JP2017035055A - Apparatus, method, and program for measuring plant growth parameters - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus, method, and program for measuring plant growth parameters, which are capable of carrying out calibration by obtaining a calibration value, even when an image picked up by a satellite the ground includes a portion where the ground is not observed.SOLUTION: A plant growth parameter measuring apparatus D according to the present invention comprises: acquiring a plurality of satellite images respectively corresponding to a plurality of wavelengths; acquiring a plurality of aircraft images obtained by picking up a partial area of the satellite image of the ground at each of the plurality of wavelengths from the aircraft; acquiring ambient light data of ambient light that illuminates the partial area; calculating a relative growth index by a relative growth index calculation unit 22 on the basis of a plurality of satellite images; calculating a calibration value by the calibration value calculation unit 24 from the absolute growth index of the partial area obtained by a partial area absolute growth index calculation unit 23 on the basis of a partial area relative growth index extracted from the relative growth index and the plurality of the aircraft images and the ambient light data; and calibrating the relative growth index by the absolute growth index calculation unit 25 using a calibration value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plant growth index measurement device, a plant growth index measurement method, and a plant growth index measurement program for obtaining a growth index that represents the degree of growth in a plant.

  In agriculture, it is necessary to appropriately carry out fertilization management such as the time of topdressing and the amount of topdressing, for example, in order to grow plants of high quality and stable crops. Therefore, the current plant state is determined. For this determination, a leaf color plate (leaf color scale) provided with a plurality of color samples whose colors gradually changed from yellowish green to dark green, for example, since the darkness of the leaf color represents the state of the plant. It is used. Since the determination of the state of a plant using such a leaf-colored plate is a subjective determination or is not suitable for agricultural industrialization, various devices have been researched and developed in recent years. For example, there is a field management support method disclosed in Patent Document 1.

  The field management support method disclosed in Patent Document 1 is a field management support method that supports farm work for each crop variety in a management target field, and the support device that supports farm work in a field includes a management target field. A first vegetation index representing the amount and activity of cultivars of crop varieties in the field to be managed is calculated based on the wavelength components of the red wavelength and near infrared wavelength of the satellite image data obtained by photographing the region, and stored in the growth index database. A second step of accepting a fixed point actual value of the growth index representing the growth status of the crop in the management target field and storing it in the fixed point growth index database; and a vegetation index at the observation position of the fixed point actual value of the growth index Based on the third step acquired from the growth index database, the vegetation index acquired from the growth index database, and the fixed point actual value of the growth index. The fourth step of calculating a regression curve by the least square method with the vegetation index as the X-axis and the growth index fixed point actual measurement value as the Y-axis, and using the regression curve, the correction data for the growth index in the managed field is calculated. A fifth step of storing in the corrected growth index database, a sixth step of acquiring correction data of the growth index corresponding to the management target field from the corrected growth index database based on the coordinate values of the management target field, and management A seventh step of displaying the correction data of the growth index corresponding to the target field in a display form corresponding to the growth state with the graphic representing the management target field for each year, and supporting farm work in the management target field Is.

Japanese Patent No. 4873545

  By the way, in the field management support method disclosed in Patent Document 1, correction data (calibration value) is calculated via a regression curve based on a fixed point actual value of a vegetation index based on satellite image data and a growth index on the ground. Thus, the vegetation index based on the satellite image data is calibrated (calibrated) based on the fixed point actual measurement value of the growth index on the ground. For this reason, when the fixed point of the fixed point actual measurement value cannot be seen from the satellite by, for example, a cloud, fog, an aircraft, or the like, there is no vegetation index based on the satellite image data corresponding to the fixed point actual measurement value. There was a possibility that correction data (calibration value) could not be calculated and calibration (calibration) could not be performed.

  The present invention has been made in view of the above circumstances, and its object is to provide a plant growth index measuring apparatus and a plant that can calibrate by obtaining a calibration value even when there is a portion where the ground cannot be seen in a satellite image. It is to provide a growth index measurement method and a plant growth index measurement program.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, the plant growth index measuring apparatus according to one aspect of the present invention acquires a plurality of satellite images corresponding to each of the plurality of wavelengths obtained by imaging the ground from the satellite at a plurality of different wavelengths. An acquisition unit and a partial region that is a partial region in which the ground is reflected in the satellite image acquired by the satellite image acquisition unit are captured from the aircraft at each of the plurality of wavelengths, corresponding to each of the plurality of wavelengths. An aircraft image acquisition unit that acquires a plurality of aircraft images, an ambient light acquisition unit that acquires a light amount or an incidence rate in ambient light illuminating the partial area, and the plurality of satellite images acquired by the satellite image acquisition unit Based on the relative growth index calculation unit to obtain a relative growth index relatively representing the degree of growth in the plant, and the aircraft image acquisition unit acquired Based on the number of aircraft images and the amount of light or incident rate acquired by the ambient light acquisition unit, a partial region absolute growth index calculation unit for obtaining a partial region absolute growth index that absolutely represents the degree of growth in plants, The relative growth index corresponding to the partial area of the relative growth index obtained by the relative growth index calculation unit is obtained as a partial area relative growth index, and the obtained partial area relative growth index and the partial area absolute growth are obtained. Based on the partial region absolute growth index obtained by the index calculation unit, a calibration value calculation unit for obtaining a calibration value for ablating the partial region relative growth index, and the relative value obtained by the relative growth index calculation unit And an absolute growth index calculation unit that calculates an absolute growth index by calibrating the growth index with the calibration value obtained by the calibration value calculation unit.

  Such a plant growth index measuring apparatus acquires a plurality of satellite images corresponding to each of a plurality of wavelengths captured by the satellite image acquisition unit as the imaging target from the satellite, and the satellite image acquisition unit acquires the satellite image. A plurality of aircraft images corresponding to each of the plurality of wavelengths obtained by imaging a partial area, which is a partial area in which the ground is reflected, are illuminated by the ambient light acquisition unit. The amount of light in the ambient light or the incident rate is acquired. In this way, even when there are portions where the ground cannot be seen due to, for example, clouds, fog, etc., in the plurality of satellite images from the satellite, the ground is captured avoiding portions where the ground is not reflected in the satellite image. A plurality of aircraft images corresponding to the partial area and the light amount or incident rate (hereinafter abbreviated as “environment light data”) in the environmental light illuminating the partial area can be acquired. That is, a plurality of satellite images, a plurality of aircraft images, and the ambient light data in a set of the partial areas in which the ground is reflected can be acquired. For this reason, the plant growth index measuring apparatus is configured such that, in the partial area, the partial area relative growth index based on a plurality of satellite images, a plurality of aircraft images, and the ambient light data are used in the partial area. The calibration value can be obtained based on the partial region absolute growth index, and the relative growth index based on the plurality of satellite images can be calibrated with the calibration value by the absolute growth index calculation unit. Therefore, the plant growth index measuring apparatus can obtain an absolute growth index in which the relative growth index is calibrated to the calibration value.

  Further, in another aspect, in the above-described plant growth index measuring apparatus, each of the plurality of wavelengths obtained by imaging the satellite image acquisition unit at a predetermined target time from the satellite as an imaging target at each of the plurality of wavelengths. An absolute growth index storage unit that acquires a plurality of satellite images at the target time corresponding to the target time and stores an absolute growth index at the past time obtained at the past time that is past the target time in the imaging target. Further, the relative growth index calculation unit obtains the relative growth index as a target time relative growth index based on a plurality of satellite images at the target time acquired by the satellite image acquisition unit, and the calibration value calculation unit Is a part of the target time relative growth index obtained by the relative growth index calculation unit in which the ground is reflected in each of the plurality of satellite images at the target time. The second partial area corresponding to the second partial area of the second partial area relative growth index corresponding to the second partial area and the absolute growth index at the past time stored in the absolute growth index storage unit. A second calibration value for absoluteizing the second partial region relative growth index is obtained based on the partial growth absolute growth index, and the absolute growth index calculation unit is the relative growth index calculation unit. The absolute growth index at the target time is further obtained by calibrating the obtained target time relative growth index with the second calibration value obtained by the calibration value calculation unit.

  Such a plant growth index measuring apparatus can obtain the second calibration value by using the absolute growth index at the past time. Therefore, even if the plant growth index measuring device cannot acquire the plurality of aircraft images and the ambient light data, the target growth time can be obtained by calibrating the relative growth index at the target time with the second calibration value. The absolute growth index can be obtained.

  Moreover, in another aspect, in the above-described plant growth index measuring apparatus, the satellite image acquisition unit captures the ground from the satellite at each of the plurality of wavelengths as an imaging target at a predetermined target time. An absolute growth index storage unit that acquires a plurality of satellite images at the target time corresponding to each, and stores an absolute growth index at a past time obtained at a past time that is past the target time in the imaging target. And the correspondence information storage unit that stores the correspondence between the date and the growth index, and the plurality of satellite images at the target time acquired by the satellite image acquisition unit, the target is Based on the time, the absolute growth index at the past time stored in the absolute growth index storage unit, and the correspondence stored in the correspondence information storage unit, the target time Characterized in that it further comprises an absolute growth index estimation unit for estimating the absolute growth index. Preferably, in the above-described plant growth index measuring apparatus, the absolute growth index estimation unit obtains a deviation amount between the absolute growth index and the correspondence relationship at the past time, and shifts the correspondence relationship by the obtained deviation amount. An estimated correspondence is obtained by (shifting), and an absolute growth index at the target time is estimated by obtaining a growth index at the target time from the estimated correspondence.

  Since such a plant growth index measuring apparatus further includes the absolute growth index storage unit, the correspondence relationship information storage unit, and the absolute growth index estimation unit, a plurality of the time points at the target time acquired by the satellite image acquisition unit. Even when the ground is not shown in the satellite image, the absolute growth index at the target time can be obtained.

  In the plant growth index measurement method according to another aspect of the present invention, a plurality of satellite images corresponding to each of the plurality of wavelengths obtained by imaging the ground as an imaging target from a satellite at each of a plurality of different wavelengths are obtained. In each of the plurality of wavelengths, a part of the satellite image acquired in the satellite image acquisition step and a part of the satellite image acquired in the satellite image are captured at a plurality of wavelengths from the aircraft. An aircraft image acquisition step of acquiring a plurality of corresponding aircraft images, an environmental light acquisition step of acquiring a light amount or an incident rate in ambient light illuminating the partial area, and the plurality of acquired in the satellite image acquisition step A relative growth index calculation step for obtaining a relative growth index relatively representing the degree of growth in the plant based on the satellite image; and the aircraft image acquisition process A partial region absolute growth index for obtaining a partial region absolute growth index that absolutely represents the degree of growth in a plant based on the plurality of aircraft images acquired in step 1 and the light quantity or incidence rate acquired in the ambient light acquisition step A relative growth index corresponding to the partial area of the relative growth index determined in the calculation step and the relative growth index calculation step is determined as a partial area relative growth index, and the calculated partial area relative growth index and the one On the basis of the partial region absolute growth index obtained in the partial region absolute growth index calculation step, a calibration value calculation step for obtaining a calibration value for absoluteizing the partial region relative growth index, and in the relative growth index calculation step An absolute growth index calculation step for obtaining an absolute growth index by calibrating the calculated relative growth index with the calibration value obtained in the calibration value calculation step. That.

  Furthermore, the plant growth index measurement program according to another aspect of the present invention is a computer-aided program for imaging a plurality of satellite images corresponding to each of the plurality of wavelengths obtained by imaging the ground from the satellite at each of a plurality of different wavelengths. A plurality of the plurality of the plurality of wavelengths captured from the aircraft at each of the plurality of wavelengths. Acquired in an aircraft image acquisition step of acquiring a plurality of aircraft images corresponding to each wavelength, an ambient light acquisition step of acquiring a light amount or incidence rate in ambient light illuminating the partial area, and the satellite image acquisition step Based on the plurality of satellite images, a relative growth index calculating step for obtaining a relative growth index relatively representing the degree of growth in the plant; Based on the plurality of aircraft images acquired in the aircraft image acquisition step and the light quantity or incidence rate acquired in the ambient light acquisition step, a partial region absolute growth index that absolutely represents the degree of growth in a plant is obtained. The relative growth index corresponding to the partial area of the relative growth index calculated in the partial area absolute growth index calculation step and the relative growth index calculation step is determined as the partial area relative growth index, and the calculated partial area relative Based on the growth index and the partial growth absolute growth index calculated in the partial growth absolute growth index calculation step, a calibration value calculation step for obtaining a calibration value for ablating the partial growth relative growth index, and the relative Absolute growth index calculation step for obtaining an absolute growth index by calibrating the relative growth index obtained in the growth index calculation step with the calibration value obtained in the calibration value calculation step Is a program for executing the.

  Such a plant growth index measurement method and a plant growth index measurement program acquire a plurality of satellite images corresponding to each of a plurality of wavelengths captured from the satellite as an imaging target through a satellite image acquisition step, and acquire an aircraft image. In the step, a plurality of aircraft images corresponding to each of the plurality of wavelengths obtained by imaging a partial region that is a partial region in which the ground is reflected in the satellite image are obtained. The amount of light or the incidence rate of ambient light that illuminates a partial area is acquired. In this way, even when there are portions where the ground cannot be seen due to, for example, clouds, fog, etc., in the plurality of satellite images from the satellite, the ground is captured avoiding portions where the ground is not reflected in the satellite image. A plurality of aircraft images corresponding to the partial area and the ambient light data can be acquired. That is, a plurality of satellite images, a plurality of aircraft images, and the ambient light data in a set of the partial areas in which the ground is reflected can be acquired. For this reason, the plant growth index measurement method and the program include the partial basin relative growth index based on a plurality of satellite images, a plurality of aircraft images, and the ambient light data in the partial area by a calibration value calculation step. The calibration value can be obtained based on the partial region absolute growth index according to the above, and the relative growth index based on the plurality of satellite images can be calibrated with the calibration value by the absolute growth index calculation step. Therefore, the plant growth index measurement method and the program can determine an absolute growth index in which the relative growth index is calibrated to the calibration value.

  The plant growth index measuring apparatus, the plant growth index measuring method, and the plant growth index measuring program according to the present invention can calibrate by obtaining a calibration value even when there is a portion where the ground cannot be seen in the satellite image.

It is a block diagram which shows the structure of the plant growth parameter | index measuring apparatus in embodiment. It is a block diagram which shows the structure of the aircraft in embodiment. It is a figure for demonstrating an incidence rate. It is a flowchart which shows operation | movement of the plant growth parameter | index measuring apparatus in embodiment. It is a figure for demonstrating operation | movement of the 1st aspect in the calibration process shown in FIG. It is a flowchart which shows operation | movement of the 1st aspect in the calibration process shown in FIG. It is a figure which shows an example of a relative NDVI image based on a satellite image and the said satellite image. It is a figure which shows an example of an absolute NDVI image based on an aircraft image and the said aircraft image. It is a figure for demonstrating operation | movement of the 2nd aspect in the calibration process shown in FIG. It is a flowchart which shows the operation | movement of the 2nd aspect in the calibration process shown in FIG. It is a figure for demonstrating the operation | movement of the 3rd aspect in the calibration process shown in FIG.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably. In this specification, when referring generically, it shows with the reference symbol which abbreviate | omitted the suffix, and when referring to an individual structure, it shows with the reference symbol which attached the suffix.

  First, the structure of the plant growth parameter | index measuring apparatus in this embodiment is demonstrated. FIG. 1 is a block diagram illustrating a configuration of a plant growth index measuring apparatus according to an embodiment. FIG. 2 is a block diagram illustrating a configuration of the aircraft in the embodiment. FIG. 3 is a diagram for explaining the incidence rate. FIG. 3A shows the case of the incidence rate of the first mode, and FIG. 3B shows the case of the incidence rate of the second mode. The horizontal axis in FIG. 3 is the wavelength, and the vertical axis is the intensity.

  The plant growth index measuring apparatus in the embodiment uses a predetermined calibration value (calibration value) for a growth index (relative growth index) obtained based on a plurality of satellite images corresponding to a plurality of different wavelengths. It is a device for obtaining an absolute growth index by calibrating. The plant growth index measuring device D in such an embodiment includes an interface unit (IF unit) 1, a control processing unit 2, and a storage unit 3, as shown in FIG. Then, an input unit 4 and an output unit 5 are further provided.

  The IF unit 1 is an interface circuit that is connected to the control processing unit 2 and inputs / outputs data to / from an external device according to the control of the control processing unit 2. For example, the IF unit 1 uses the Bluetooth (registered trademark) standard for data A Bluetooth interface circuit for inputting / outputting data, an IrDA interface circuit for inputting / outputting data using the IrDA (Infrared Data Association) standard, a USB interface circuit for inputting / outputting data using the USB (Universal Serial Bus) standard, and the like. The IF unit 1 may be a communication circuit (communication card) that is connected to the control processing unit 2 and performs wired or wireless communication according to the control of the control processing unit 2. Such an IF unit 1 generates a communication signal containing data to be transferred input from the control processing unit 2 according to a communication protocol used in the communication network, and generates the generated communication signal via the communication network. Send to external device. The IF unit 1 receives a communication signal from the external device via the communication network, extracts data from the received communication signal, and converts the extracted data into data in a format that can be processed by the control processing unit 2. To the control processing unit 2. The IF unit 1 receives the plurality of satellite images, the plurality of aircraft images from an external device (for example, a server device or a USB memory) that stores a plurality of satellite images, a plurality of aircraft images, and ambient light data corresponding to the aircraft images. Acquiring the image and the ambient light data corresponding to the aircraft image corresponds to an example of each of the satellite image acquisition unit, the aircraft image acquisition unit, and the ambient light acquisition unit.

  The plurality of satellite images are a plurality of images corresponding to each of the plurality of wavelengths obtained by imaging (capturing) the ground from the satellite at each of a plurality of different wavelengths.

  The plurality of aircraft images correspond to each of the plurality of wavelengths obtained by imaging a partial region that is a partial region in which the ground is reflected in the satellite image acquired by the IF unit 1 from the aircraft at each of the plurality of wavelengths. A plurality of images.

  The ambient light data corresponding to the aircraft image is a light amount or an incidence rate in ambient light that illuminates a partial region in the aircraft image. As shown in FIG. 3 (A), the incident rate is a ratio (Eaim / Eall) of the energy Eaim of the target wavelength λaim to the total energy Eall over the entire wavelength range in which ambient light is measured, or FIG. 3 (B). , The ratio (Eaim / Eref) of the energy Eaim of the target wavelength λaim to the energy Eref of the predetermined contrast wavelength λref.

  The plurality of aircraft images corresponding to each of the plurality of wavelengths include, for example, an airplane, a helicopter, a multi-vehicle that is equipped with a camera capable of generating an image at each of the plurality of wavelengths, or is operated by radio-controlled flight (guided flight) or autonomous flight. Obtained by unmanned aerial vehicles (drones) such as copter and balloon. In addition, the ambient light may be measured by an ambient light measurement unit that measures the ambient light mounted on such an aircraft, and the ambient light measurement unit is arranged near the partial area. It may be measured by a measuring unit.

  Such an aircraft UAV includes, for example, a GPS (Global Positioning System) 61, a flight mechanism unit 62, a UAV control processing unit 63, an imaging unit 64, and a UAV storage as shown in FIG. Unit 65, UAV interface unit (UAVIF unit) 66, and ambient light measurement unit 67. In this example, the ambient light is measured by the ambient light measurement unit 67 mounted on the aircraft.

  The GPS 61 is a device that is connected to the UAV control processing unit 63 and measures the position of the aircraft UAV by a satellite positioning system for measuring the current position on the earth according to the control of the UAV control processing unit 63. The result (latitude X, longitude Y, altitude Z) is output to the UAV control processing unit 63. The GPS 61 may be a GPS having a correction function for correcting an error such as DGSP (Differential GSP).

  The flight mechanism unit 62 is connected to the UAV control processing unit 63 and is a mechanism for flying the aircraft UAV according to the control of the UAV control processing unit 63. The flight mechanism unit 62 includes, for example, a plurality of rotors (rotary blades) that are arranged radially, a power unit that is connected to the UAV control processing unit 63 and rotates the plurality of rotors in a balanced manner according to the control of the UAV control processing unit 63, and And a gyro sensor for detecting the inclination of the aircraft UAV.

  The imaging unit 64 is connected to the UAV control processing unit 63 and, according to the control of the UAV control processing unit 63, captures a plurality of images corresponding to each of the plurality of wavelengths captured by imaging the ground at a plurality of different wavelengths. It is a device to generate. More specifically, the imaging unit 64 includes a visible imaging unit that generates a visible light image (visible image) and an infrared imaging unit that generates an infrared light image (infrared image). The visible imaging unit, for example, a first band pass filter that transmits light in a relatively narrow band having a wavelength of 550 nm as a center wavelength, and an optical image of visible light of an imaging target that has passed through the first band pass filter A first image-forming optical system that forms an image on an image-forming surface; a first image-forming optical system that is disposed so that a light-receiving surface coincides with the first image-forming surface; An image sensor, and a first digital signal processor (DSP) configured to perform known image processing on the output of the first image sensor to generate image data (visible aircraft image) with visible light, and the like. A so-called camera (visible camera) or the like. The infrared imaging unit, for example, a second bandpass filter that transmits light in a relatively narrow band having a wavelength of 850 nm as a center wavelength, and an optical image of infrared light of an imaging target that has passed through the second bandpass filter. A second image forming optical system that forms an image on a predetermined image forming surface, a light receiving surface that is aligned with the second image forming surface, and converts an optical image of the infrared light of the imaged object into an electrical signal A second image sensor configured to include a second DSP that performs known image processing on the output of the second image sensor to generate data of an infrared image (infrared aircraft image). An infrared camera or the like. The visible imaging unit outputs data of the visible aircraft image in visible light to the UAV control processing unit 63, and the infrared imaging unit outputs data of the infrared aircraft image in infrared light to the UAV control processing unit. To 63. The UAV control processing unit 63 stores the visible aircraft image data and the infrared aircraft image data in the UAV storage unit 65 in association with each other. The visible imaging unit and the infrared imaging unit are arranged so as to capture the same imaging target.

  In the above description, the imaging unit 64 includes the visible imaging unit and the infrared imaging unit. However, the imaging unit 64 receives the R pixel that receives red, the G pixel that receives green, and the blue. An image sensor (RGBIr image sensor) having a unit arrangement in which B pixels that perform IR and Ir pixels that receive infrared light are arranged in 2 rows and 2 columns, W pixels that receive white, Y pixels that receive yellow, and red An image sensor (WYRIr image sensor) having a unit arrangement in which R pixels and Ir pixels that receive infrared light are arranged in two rows and two columns may be used, and may be configured with one camera. In this case, for example, the output of the R pixel and the output of the Ir pixel are used for the calculation of the growth index. Further, for example, the output of the G pixel and the output of the Ir pixel are used for calculating the growth index. Further, for example, the output of the B pixel and the output of the Ir pixel are used for calculating the growth index. Further, for example, the output of the W pixel and the output of the Ir pixel are used for the calculation of the growth index. For example, the output of the Y pixel and the output of the Ir pixel are used for the calculation of the growth index.

  The ambient light measuring unit 67 is an apparatus that is connected to the UAV control processing unit 63 and measures the ambient light that illuminates the partial area imaged by the imaging unit 64 under the control of the UAV control processing unit 63. For this reason, the ambient light measurement unit 67 is preferably arranged so that the incident aperture that captures ambient light is oriented in a direction substantially opposite to the imaging direction of the imaging unit 64. For example, the imaging unit 64 is disposed so as to face downward, and the ambient light measurement unit 67 is disposed so as to face upward. Such an ambient light measurement unit 67 includes, for example, a visible camera similar to the imaging unit 64. In this case, the amount of light is obtained. Further, for example, the ambient light measurement unit 67 is configured to include a spectrometer, and in this case, the incidence rate is obtained. The ambient light measurement unit 67 outputs the measurement result (visible image or wavelength spectrum) to the UAV control processing unit 63. The UAV control processing unit 63 obtains ambient light data from the measurement result, and the obtained ambient light data. Are stored in the UAV storage unit 65 in association with the data of the visible aircraft image and the data of the infrared aircraft image.

  The UAVIF unit 66 is an interface circuit that is connected to the UAV control processing unit 63 and inputs / outputs data to / from an external device under the control of the UAV control processing unit 63 as in the case of the IF unit 1 described above.

  The UAV storage unit 65 is a circuit that is connected to the UAV control processing unit 63 and stores various predetermined programs and various predetermined data under the control of the UAV control processing unit 63. The various predetermined programs include, for example, control processing programs such as a control program for controlling each part of the aircraft UAV in accordance with the function of each part, and an autonomous flight program for autonomous flight. The various predetermined data include the plurality of aircraft images (in this example, visible aircraft images) obtained by imaging the partial area, such as the position information of the departure point and the destination point, from the aircraft UAV at each of the plurality of wavelengths. And infrared aircraft images), and necessary data for obtaining ambient light data for the partial area is included. The UAV storage unit 65 includes, for example, a ROM (Read Only Memory) that is a nonvolatile storage element, an EEPROM (Electrically Erasable Programmable Read Only Memory) that is a rewritable nonvolatile storage element, and the like. The UAV storage unit 65 includes a RAM (Random Access Memory) serving as a working memory for the so-called UAV control processing unit 63 that stores data generated during execution of the predetermined program.

  The UAV control processing unit 63 controls each part of the aircraft UAV according to the function of each part, captures the partial area at each of the plurality of wavelengths, and obtains the plurality of aircraft images. This is a circuit for obtaining ambient light data for. The UAV control processing unit 63 includes, for example, a CPU (Central Processing Unit) and its peripheral circuits.

  In such an aircraft UAV, first, the position information (for example, latitude, longitude and altitude) of the departure point detected by the GPS 61 or the position information of the departure point input via the UAVIF unit 66 is stored in the UAV storage unit 65. Then, the position information (for example, latitude, longitude, and altitude) of the destination point input via the UAVIF unit 66 is stored in the UAV storage unit 65. The aircraft UAV autonomously flies from the departure point to the destination corresponding to the position information stored in the UAV storage unit 65 by controlling the flight mechanism unit 62 by the UAV control processing unit 63. When the aircraft UAV reaches the destination point, the UAV control processing unit 63 controls the imaging unit 64 to generate a plurality of aircraft images (in this example, a visible aircraft image and an infrared aircraft image). Store in the UAV storage unit 65. Thereby, a plurality of aircraft images corresponding to each of the plurality of wavelengths, obtained by looking down at the partial area, are obtained. At this time, the aircraft UAV controls the ambient light measurement unit 67 by the UAV control processing unit 63 to measure the ambient light illuminating the partial area, and the ambient light data obtained from the measurement result is obtained as the UAV. Store in the storage unit 65. When these multiple aircraft images and ambient light data are obtained, the aircraft UAV controls the flight mechanism unit 62 by the UAV control processing unit 63, thereby returning to the departure point corresponding to the position information stored in the UAV storage unit 65. Fly autonomously from the destination and return. When the aircraft UAV returns to the departure point, each data of the visible aircraft image and the infrared aircraft image and the ambient light data stored in the UAV storage unit 65 are transferred to the external device (for example, a server device or a USB memory) via the UAVIF unit 66. Etc.). In this example, the return point is the same as the departure point, but may be different. Further, instead of autonomous flight, wireless flight by operator operation (maneuvering) may be used.

  Returning to FIG. 1, the input unit 4 is connected to the control processing unit 2 to obtain various commands such as a command for instructing the start of calculation of the growth index and a growth index such as a field name to be measured. Is a device for inputting various data necessary for the plant growth index measuring device D, such as a keyboard and a mouse. The output unit 5 is connected to the control processing unit 2, and according to the control of the control processing unit 2, the command and data input from the input unit 4, the relative growth index obtained by the plant growth index measuring device D, and the absolute A device that outputs a measurement result such as a growth index, for example, a display device such as a CRT display, an LCD and an organic EL display, or a printing device such as a printer.

  A touch panel may be configured from the input unit 4 and the output unit 5. In the case of configuring this touch panel, the input unit 4 is a position input device that detects and inputs an operation position such as a resistive film method or a capacitance method, and the output unit 5 is a display device. In this touch panel, a position input device is provided on the display surface of the display device, one or more input content candidates that can be input to the display device are displayed, and the user touches the display position where the input content to be input is displayed. Then, the position is detected by the position input device, and the display content displayed at the detected position is input to the plant growth index measuring device D as the user operation input content. In such a touch panel, since the user can easily understand the input operation intuitively, a plant growth index measuring device D that is easy for the user to handle is provided.

  The storage unit 3 is a circuit that is connected to the control processing unit 2 and stores various predetermined programs and various predetermined data under the control of the control processing unit 2. The various predetermined programs include, for example, a control program that controls each part of the plant growth index measuring device D according to the function of each part, and the degree of growth in the plant based on a plurality of satellite images. Absolutely represents the degree of growth in plants based on a relative growth index calculation program for obtaining the relative growth index shown in FIG. 5 and a plurality of aircraft images and ambient light amounts or incident rates (environmental light data) for some areas. A partial area absolute growth index calculation program for obtaining a partial area absolute growth index, or a relative growth index corresponding to the partial area of the relative growth index obtained by the relative growth index calculation program as a partial area relative growth index The partial growth relative growth index obtained and the partial growth absolute growth index obtained by the partial growth absolute growth index calculation program. Based on the above, the calibration value calculation program for obtaining a calibration value for abating the partial region relative growth index, and the relative growth index obtained by the relative growth index calculation program was obtained by the calibration value calculation program A control processing program such as an absolute growth index calculation program for obtaining an absolute growth index by calibrating with the calibration value is included. The various predetermined data correspond to an identifier (for example, a field name) for identifying and identifying a field to be measured, a plurality of satellite images corresponding to each of the plurality of wavelengths, and each of the plurality of wavelengths. A plurality of aircraft images, ambient light data, a relative growth index determined by the relative growth index calculation program, a partial area absolute growth index determined by the partial area absolute growth index calculation program, and the calibration Includes calibration data obtained by the value calculation program, absolute growth index obtained by the absolute growth index calculation program, and data necessary for obtaining the absolute growth index such as selected place information that is information indicating the partial area. It is. Similarly to the UAV storage unit 65, the storage unit 3 includes a ROM, an EEPROM, and the like, and a RAM serving as a working memory of the so-called control processing unit 2 that stores data generated during execution of the predetermined program. Including. The storage unit 3 may include a relatively large capacity hard disk.

  The storage unit 3 functionally stores a satellite image storage unit 31 that stores the plurality of satellite images and an aircraft image that stores the plurality of aircraft images in order to store a part of the various predetermined data. A storage unit 32; an ambient light information storage unit 33 for storing the ambient light data; a relative growth index storage unit 34 for storing the relative growth index; and an absolute growth index storage unit for storing the partial region absolute growth index and the absolute growth index. 35, a calibration value storage unit 36 for storing the calibration value, and a selection location information storage unit 37 for storing the selection location information.

  The control processing unit 2 is a circuit for controlling each part of the plant growth index measuring device D according to the function of each part and obtaining an absolute growth index. The control processing unit 2 includes, for example, a CPU (Central Processing Unit) and its peripheral circuits. In the control processing unit 2, a control processing program is executed, whereby a control unit 21, a relative growth index calculation unit 22, a partial region absolute growth index calculation unit 23, a calibration value calculation unit 24, and an absolute growth index calculation unit 25. Is functionally configured.

  The control part 21 controls each part of the plant growth parameter | index measuring apparatus D according to the function of the said each part, respectively.

  The relative growth index calculation unit 22 obtains a relative growth index that relatively represents the degree of growth in plants based on a plurality of satellite images acquired by the IF unit 1 as an example of a satellite image acquisition unit. The growth index is an index representing the degree of growth in the plant. For example, NDVI (Normalized Difference Vegetation Index, Normalized Vegetation Index), RVI (Ratio Vegetation Index, Specific Vegetation Index), DVI (Difference Vegetation Index, Difference Index Vegetation Index, ), TVI (Transformed Vegetation Index), IPVI (Infrared Percentage Index), and the like. The NDVI value may be converted into a SPAD (Soil & Plant Analyzer Development) value by a known conversion formula. In the present embodiment, for example, the relative NDVI value Vrel is obtained as an example of the relative growth index from the luminance value Gp of the wavelength 550 nm and the luminance value Ip of the wavelength 850 nm in the satellite image (Vrel = (Ip−Gp) / (Ip + Gp)). ).

  The partial region absolute growth index calculation unit 23 is based on a plurality of aircraft images acquired by the IF unit 1 as an example of an aircraft image acquisition unit and ambient light data acquired by the IF unit 1 as an example of an ambient light acquisition unit. A partial region absolute growth index that absolutely represents the degree of growth in a plant is obtained. For example, the absolute NDVI value Vabs in a partial region is partially obtained from the brightness value Ga of wavelength 550 nm, the brightness value Ia of wavelength 850 nm, the ambient light data Gc of wavelength 550 nm, and the ambient light data Ic of wavelength 850 nm in an aircraft image. Obtained as an example of the region absolute growth index (Vabs = ((Ia / Ic) − (Ga / Gc)) / ((Ia / Ic) + (Ga / Gc)) in the case of light intensity] Vabs = ( (Ia / 1)-(Ga / (Gc / Ic))) / ((Ia / 1) + (Ga / (Gc / Ic)) Note that when the ambient light data is a light amount, the ambient light data When the ambient light data has an incident rate, the brightness values at the respective wavelengths of the aircraft image data are equal to each other at the same exposure time. The amount of light is converted to a considerable amount.

  The calibration value calculation unit 24 calculates a relative growth index corresponding to the partial region among the relative growth indexes calculated by the relative growth index calculation unit 22 as a partial region relative growth index, Based on the partial area absolute growth index obtained by the partial area absolute growth index calculation unit 23, a calibration value (first calibration value) C1 for ablating the partial area relative growth index is obtained. .

  The absolute growth index calculation unit 25 calculates the absolute growth index by calibrating the relative growth index obtained by the relative growth index calculation unit 22 with the first calibration value C1 obtained by the calibration value calculation unit 24.

  Next, operation | movement of the plant growth parameter | index measuring apparatus in this embodiment is demonstrated. FIG. 4 is a flowchart showing the operation of the plant growth index measuring apparatus in the embodiment. FIG. 5 is a diagram for explaining the operation of the first mode in the calibration processing shown in FIG. FIG. 6 is a flowchart showing the operation of the first mode in the calibration process shown in FIG. FIG. 7 is a diagram illustrating an example of a satellite image and a relative NDVI image based on the satellite image. 7A shows an image of a predetermined area including the measurement target field AR1 as a reference, and FIG. 7B shows an image of the measurement target field AR1 imaged in the visible wavelength band as a reference. FIG. 7C shows, as an example, a satellite image (visible satellite image) obtained by imaging the field AR1 to be measured shown in FIGS. 7A and 7B from the satellite at a wavelength of 550 nm, and FIG. Shows, as an example, a satellite image (infrared satellite image) obtained by imaging the field AR1 to be measured shown in FIGS. 7A and 7B from the satellite at a wavelength of 850 nm, and FIG. The measurement target field generated from the visible satellite image shown in FIG. 7C and the infrared satellite image shown in FIG. 7D by obtaining the NDVI value from each pixel value (luminance value) at the pixel at the same position. The relative NDVI image of AR1 is shown. FIG. 8 is a diagram illustrating an example of an aircraft image and an absolute NDVI image based on the aircraft image. FIG. 8A shows an image of a predetermined area including the measurement target field AR1 as a reference, and FIG. 8B shows a partial region in the measurement target field AR1 captured in the visible wavelength band as a reference. FIG. 8C shows, as an example, an aircraft image obtained by imaging a partial area AR2 in the measurement target field AR1 shown in FIGS. 8A and 8B from the aircraft UAV at a wavelength of 550 nm (visible). FIG. 8D shows, as an example, an aircraft image (infrared image) obtained by imaging a partial region AR2 in the measurement target field AR1 shown in FIGS. 8A and 8B from the aircraft at a wavelength of 850 nm. FIG. 8 (E) shows the visible aircraft image shown in FIG. 8 (C) and FIG. 8 (D) by obtaining the NDVI value from each pixel value (luminance value) in the pixels at the same position. Indicated in Generated from the infrared aircraft image, indicating the absolute NDVI image of a part AR2 in the field AR1 measured.

  In such a plant growth index measuring device D, when a power switch (not shown) is turned on by a user (operator), the control processing unit 2 executes initialization of each necessary unit, and by executing the control processing program, In the control processing unit 2, a control unit 21, a relative growth index calculation unit 22, a partial region absolute growth index calculation unit 23, a calibration value calculation unit 24, and an absolute growth index calculation unit 25 are functionally configured.

  In FIG. 4, a plurality of satellite images corresponding to each of the plurality of wavelengths are acquired from the IF unit 1 by the control processing unit 2, and the acquired plurality of satellite images are satellites of the storage unit 3 by the control processing unit 2. It is stored in the image storage unit 31 (S1). For example, in the case where the field AR1 shown in FIGS. 7A and 7B is a measurement target, the data of the visible satellite image of the field AR1 captured at the wavelength 550 nm shown in FIG. 7C and FIG. Data of the infrared satellite image of the field AR1 captured at a wavelength of 850 nm shown in (D) is, for example, from a server device that manages and provides each data of the visible satellite image and the infrared satellite image by the control processing unit 2. Obtained via the IF unit 1 and stored in the satellite image storage unit 31. As a server device that manages and provides such satellite images, for example, there is Landsat (http://Landsat.usgs.gov/landsat8.php).

  Next, a relative growth index is determined by the relative growth index calculation unit 22 of the control processing unit 2 based on the acquired satellite images, and the relative growth index calculation unit 22 stores the calculated relative growth index. 3 is stored in the relative growth index storage unit 34 (S2). More specifically, for example, the relative growth index calculation unit 22 takes out each data of the visible satellite image and the infrared satellite image stored in the satellite image storage unit 31, and for all the pixels, in each pixel at the same position. A relative NDVI value Vrel is obtained from each pixel value (luminance value) as an example of the relative growth index, and a relative NDVI image (relative NDVI map) having the relative NDVI value Vrel as a pixel value is generated. For example, when the pixel values (luminance values) of the visible satellite image and the infrared satellite image at the pixel position (i, j) are Gp (i, j) and Ip (i, j), the pixel position (i, j ) Is the relative NDVI value Vrel (i, j) of the pixel at the pixel position (i, j) as Vrel (i, j) = (Ip (i, j) −Gp (i, j)). ) / (Ip (i, j) + Gp (i, j)). In one example, Vrel (i, j) is obtained for each of all pixels from the visible satellite image shown in FIG. 7C and the infrared satellite image shown in FIG. An NDVI image is generated. In FIG. 7E, relative NDVI values that can be taken as numerical values are divided in advance into a plurality of sections, and different gradations are assigned in advance to the sections, and the relative NDVI values Vrel (i) obtained as described above are obtained. , J), each pixel is displayed with the gradation corresponding to it.

  Next, the calibration processing is executed by the control processing unit 2 to obtain the first calibration value C1, and the obtained first calibration value C1 is obtained by the calibration value calculation unit 24 in the calibration value storage unit 36 of the storage unit 3. (S3). In the present embodiment, the calibration process of the first aspect is executed as follows.

  The calibration process requires a set of a satellite image that captures the ground, an image that captures the ground from which ambient light can be measured (aircraft image in the present embodiment), and ambient light data of the ambient light. When the fixed point actual measurement value is used as in Patent Document 1, when the fixed point of the fixed point actual measurement value is not visible from the satellite, for example, by a shield such as a cloud, a fog, or an aircraft, there is no satellite image of the ground. The calibration process becomes difficult. Therefore, in the calibration process of the first aspect, for example, as shown in FIG. 5, there is a region where the ground is not reflected in the satellite image because a shield such as a cloud exists between the satellite and the ground. Even in this case, a partial area, which is a partial area in which the ground is reflected in the satellite image, is selected avoiding the area where the ground is not reflected, and the partial area is selected from the aircraft at each of the plurality of wavelengths. A plurality of aircraft images corresponding to each of the plurality of wavelengths are captured, and the ambient light illuminating the partial area is measured to determine the amount of light in the ambient light or the incident rate (environmental light data). It is done. As a result, a set (set) of the satellite image of the ground and the ground image (aircraft image in this embodiment) that can measure the ambient light and the ambient light data of the ambient light is obtained. It becomes possible.

  More specifically, in the calibration process of the first aspect, in FIG. 6, first, the partial area in which the ground in the satellite image acquired in process S <b> 1 by the user (operator) is taken as the first selected place. The first selected place is input to the plant growth index measuring device D via the input unit 4 or the IF unit 1 and stored in the selected place information storage unit 37 of the storage unit 3. Then, this first selected place is input as the destination point to the aircraft UAV via the UAVIF unit 66 and stored in the UAV storage unit 65 (S11). For example, as shown in FIG. 7A and FIG. 8A, in the field AR1 to be measured, it is not hidden by a shielding object such as a cloud, for example, and thus the ground is shown in plan view. The upper left partial area AR2 in the field AR1 is selected as the first selected place AR2, and this first selected place AR2 is input and stored in the plant growth index measuring device D, and is input and stored in the aircraft UAV. More specifically, in the plant growth index measuring apparatus D, for example, a satellite image is displayed on the output unit 5, and the outer periphery of the partial area AR2 is traced by an input operation of the input unit 4 such as a pointing device with a cursor. Alternatively, when the four vertices of the partial area AR2 are designated by the input operation of the input unit 4 with a cursor, the partial area AR2 is input and stored in the plant growth index measuring device D. In the aircraft UAV, for example, the latitude and longitude at the center position of the partial area AR2 and a predetermined altitude are input and stored in the aircraft UAV.

  When the position information of the destination point is input, the aircraft UAV autonomously flies (or radio-controlled flight) from the departure point to the destination point as described above, and when reaching the destination point, the partial area AR2 A plurality of aircraft images (visible aircraft image and infrared aircraft image in the present embodiment) corresponding to each of the plurality of wavelengths are generated and stored in the UAV storage unit 65. At that time, the ambient light measurement unit The ambient light is measured at 67, ambient light data is obtained based on the measurement result, and stored in the UAV storage unit 65. When the imaging and measurement are completed, the aircraft UAV returns autonomously (or radio-controlled flight) from the destination point to the departure point.

  Next, a plurality of aircraft images and ambient light data corresponding to each of the plurality of wavelengths obtained by the aircraft UAV are acquired from the IF unit 1 by the control processing unit 2, and the acquired plurality of The aircraft image and the ambient light data are stored in the aircraft image storage unit 32 and the ambient light information storage unit 33 in the storage unit 3 by the control processing unit 2 (S12). More specifically, when the aircraft UAV returns, for example, the UAVIF unit 66 of the aircraft UAV and the IF unit 1 of the plant growth index measuring device D are communicably connected, or a storage medium such as a USB memory, for example , The plurality of aircraft images and ambient light data stored in the UAV storage unit 65 are output from the UAVIF unit 66 of the aircraft UAV to the IF unit 1 of the plant growth index measuring device D, and the IF unit 1 Obtained from.

  Next, the control processing unit 2 obtains a partial region absolute growth index by the partial region absolute growth index calculation unit 23 and stores the calculated partial region absolute growth index in the absolute growth index storage unit 35 (S13). ). More specifically, the partial area absolute growth index calculation unit 23 extracts each data of the visible aircraft image and the infrared aircraft image stored in the aircraft image storage unit 32, and the pixels at the same position for each of all the pixels. Using the ambient light data stored in the ambient light information storage unit 33, the absolute NDVI value Vabs in the partial area is obtained as an example of the partial area absolute growth index from each pixel value (luminance value) in A partial area absolute NDVI image (partial area absolute NDVI map) having the NDVI value Vabs as a pixel value is generated. For example, the pixel values (luminance values) of the visible aircraft image and the infrared aircraft image at the pixel position (i, j) are Ga (i, j) and Ia (i, j), and the same wavelength as the wavelength of the visible aircraft image When the ambient light data of the pixel at the pixel position (i, j) is Ic, the absolute NDVI value Vabs (i, j) of a partial region in the pixel at the pixel position (i, j) Is the pixel value at the pixel position (i, j) as Vabs (i, j) = (Vabs = ((Ia / Ic) − (Ga / Gc)) / ((Ia / Ic) + (Ga / In one example, from the visible aircraft image shown in Fig. 8C and the infrared aircraft image shown in Fig. 8D, Vabs (i, j) for each of all pixels using ambient light data. To obtain a partial region shown in FIG. Absolute NDVI image is generated of.

  Next, the control processing unit 2 obtains a relative growth index corresponding to the partial area AR2 among the relative growth indices obtained in the process S2 by the calibration value calculation unit 24 as a partial area relative growth index, and the obtained part. The region relative growth index is stored in the relative growth index storage unit 34 (S14). In the present embodiment, since the relative NDVI value Vrel is obtained as the relative growth index, the relative NDVI value Vrel in the partial area AR2 is obtained as the partial area relative growth index.

  When obtaining the partial area relative growth index, a portion corresponding to the partial area AR2 in the aircraft image captured by the aircraft UAV of the relative growth index obtained in the process S2 may be designated. For example, the relative growth index obtained in step S2 is displayed on the output unit 5, and the outer periphery of the partial area AR2 is traced by an input operation of the input unit 4 such as a pointing device with a cursor, or the partial By designating the four vertices of the area AR2 by the input operation of the input unit 4 with the cursor, the partial area AR2 in the relative growth index obtained in the process S2 is input and stored in the plant growth index measuring device D. .

  Next, the control processing unit 2 uses the calibration value calculation unit 24 to calculate the partial region relative growth index (relative NDVI value Vrel in the partial region AR2 in this embodiment) and the partial region obtained in step S13. Based on the absolute growth index (in this embodiment, the absolute NDVI value Vabs in the partial area AR2), a calibration value (first calibration value) C1 for absoluteizing the partial growth relative growth index is obtained. The obtained first calibration value C1 is stored in the calibration value storage unit 36 (S15).

  More specifically, in the present embodiment, the partial region absolute growth index and the partial region relative growth index are obtained for each of the plurality of pixels as described above. For example, the average value A1 of the partial region absolute growth index obtained in the process S13 is obtained, the average value B1 of the partial region relative growth index obtained in the process S14 is obtained, and one average relative to the average value B1 of the partial region relative growth index is obtained. The ratio of the average value A1 of the partial area absolute growth index is obtained as the first calibration value C1 (C1 = A1 / B1). In the present embodiment, the calibration value calculation unit 24 obtains the average value A1 of the absolute NDVI values Vabs (i, j) in the partial area AR2 obtained in process S13, and in the partial area AR2 obtained in process S14. An average value B1 of the relative NDVI values Vrel (i, j) is obtained, and a first calibration value C1 = A1 / B1 is obtained.

  The average value A1 of the partial region absolute growth index may be a simple average, but the partial region AR2 is divided into a plurality of partial regions, and each average value is obtained for each partial region. The median value of a plurality of average values obtained for each of the partial regions may be used.

  In the calibration process of the first aspect, the first calibration value C1 is obtained by each of such processes.

  Returning to FIG. 4, the absolute growth index becomes the absolute growth of the control processing unit 2 by calibrating the relative growth index obtained in the process S2 with the first calibration value C1 obtained in the process S3 after the process S3. It is calculated | required by the index calculating part 25, and this calculated | required absolute growth index is memorize | stored in the absolute growth index memory | storage part 35 of the memory | storage part 3 by the absolute growth index calculating part 25 (S4). More specifically, for example, the absolute growth index calculation unit 25 takes out the relative growth index stored in the relative growth index storage unit 34 and the first calibration value C1 stored in the calibration value storage unit 36. By multiplying the growth index by the first calibration value C1, the relative growth index is calibrated with the first calibration value C1 to obtain an absolute growth index. In the present embodiment, the absolute growth index calculation unit 25 takes out the relative NDVI value Vrel (i, j) stored in the relative growth index storage unit 34 and the first calibration value C1 stored in the calibration value storage unit 36, For each pixel, the absolute NDVI value (i, j) is obtained by multiplying the relative NDVI value Vrel (i, j) by the first calibration value C1. In one example, when the relative NDVI image shown in FIG. 7E is calibrated with the first calibration value C1, the pixel value of the relative NDVI image (that is, the relative NDVI value Vrel (i, j)) is set to the first calibrated value for all the pixels. By multiplying the calibration value C1 of 1, an absolute NDVI image (absolute NDVI map) having the absolute NDVI value Vabs (= C1 × Vrel (i, j)) as a pixel value is generated.

  Then, the absolute growth index (in this example, an absolute NDVI image) obtained in step S4 is output to the output unit 5 by the control processing unit 2 (S5). Note that the relative growth index (relative NDVI image in this example) obtained in the process S2 may be output to the output unit 5, and a plurality of satellite images acquired in the process S1 may be output to the output unit 5. Alternatively, if necessary, the absolute growth index (in this example, an absolute NDVI image) obtained in the process S4, the relative growth index (in this example, the relative NDVI image) obtained in the process S2, and the like are passed through the IF unit 1. It can be output to an external device.

  As described above, the plant growth index measurement device D and the plant growth index measurement method and the plant growth index measurement program implemented in the present embodiment have captured the ground from the satellite as an imaging target by the above-described processing S1. The plurality of satellite images corresponding to each of the plurality of wavelengths are acquired, and the plurality of satellite images obtained by imaging the partial area AR2 that is a partial area in which the ground is reflected in the satellite image by the above-described processing S12. A plurality of aircraft images corresponding to the respective wavelengths are acquired, and the amount of light or the incident rate (environment light data) in the environmental light illuminating the partial area AR2 is acquired. In this way, even when there are portions where the ground cannot be seen due to, for example, clouds, fog, etc., in the plurality of satellite images from the satellite, the ground is captured avoiding portions where the ground is not reflected in the satellite image. A plurality of aircraft images corresponding to the partial area AR2 and the ambient light data of the ambient light illuminating the partial area AR can be acquired. That is, a plurality of satellite images, a plurality of aircraft images, and the ambient light data in a set of the partial areas AR2 in which the ground is reflected can be acquired. For this reason, the plant growth index measuring device D, the plant growth index measurement method, and the plant growth index measurement program can obtain the first calibration value C1 based on these by the calibration process S3 described above. By S4, the relative growth index based on the plurality of satellite images can be calibrated with the first calibration value C1. Therefore, the plant growth index measurement device D, the plant growth index measurement method, and the plant growth index measurement program can determine an absolute growth index in which the relative growth index is calibrated to the first calibration value C1.

  In the above-described embodiment, the absolute growth index at a past time that is earlier than the target time for which the absolute growth index is desired is obtained by the calibration process of the first aspect described above and stored in the absolute growth index storage unit 35. If there is, the absolute growth index at the target time may be obtained by any of the following calibration processes of the second and third modes.

  First, the calibration process of the second aspect will be described. FIG. 9 is a diagram for explaining the operation of the second mode in the calibration process shown in FIG. FIG. 10 is a flowchart showing the operation of the second mode in the calibration process shown in FIG.

  In the calibration process of the first aspect described above, the plurality of aircraft images are generated by imaging the partial area in which the ground in the satellite image is captured by the aircraft UAV, but the ground in the satellite image is captured. It is possible that some areas cannot be imaged by the aircraft UAV due to the presence of obstacles such as power transmission lines or prohibited areas. For this reason, in the calibration process of the second mode, as shown in FIG. 9, the target time at which the plurality of satellite images acquired in the process S <b> 1 are generated (the target date is June 15 (6 / 15)) using the absolute growth index obtained in the past (in the example shown in FIG. 9, the past month date June 10 (6/10)), the plurality of satellite images at the target time. A calibration value (second calibration value) C2 for calibrating the relative growth index based on the image is obtained, and the relative growth index based on the plurality of satellite images at the target time is calibrated with the second calibration value C2. Is done.

  In the calibration process of the second aspect, the relative growth index calculation unit 22 obtains the relative growth index as the target time relative growth index based on the plurality of satellite images at the target time, and the calibration value calculation unit 24. Is a second partial area corresponding to a second partial area that is a partial area in which the ground is reflected in each of the plurality of satellite images at the target time, out of the target time relative growth indices obtained by the relative growth index calculation unit 22. 2 partial area relative growth indices, and a second partial area absolute growth index corresponding to the second partial area among the absolute growth indices stored in the absolute growth index storage unit 35 at the past time. Based on the above, the second calibration value C2 for absoluteizing the second partial region relative growth index is obtained, and the absolute growth index calculation unit 25 obtains the target obtained by the relative growth index calculation unit 22 Time relative growth index , And requests absolute growth index in the target time by calibrating with the calibration value calculation unit the determined at 24 second calibration value C2.

  More specifically, in the calibration process of the second aspect, first, in the process S1, a predetermined target time (June 15 in the example shown in FIG. 9) is set by imaging the ground from the satellite at each of a plurality of different wavelengths. ), A plurality of satellite images at the target time corresponding to each of the plurality of wavelengths are acquired, and in processing S2, the relative growth index calculation unit 22 performs relative growth index (for example, relative at the target time). NDVI value Vrel (i, j)) is determined.

  The absolute growth index storage unit 35 stores the absolute growth index (for example, the absolute NDVI value Vabs (i, j) at the past time) at the past time (June 10 in the example shown in FIG. 9) by the above-described operation. Is stored.

  And in process S3 shown in FIG. 4, the calibration process of the 2nd aspect shown in FIG. 10 is performed. In the calibration process of the second mode, in FIG. 10, first, a partial area that is a partial area in which the ground is reflected in the satellite image at the target time acquired in the above-described process S1 by the user (operator) is displayed. The second selected place is input to the plant growth index measuring device D via the input unit 4 or the IF unit 1 and stored in the selected place information storage unit 37 of the storage unit 3. (S21). For example, in the plant growth index measuring apparatus D, a satellite image at the target time is displayed on the output unit 5, and the outer periphery of a partial area as the second selected place is a cursor, for example, an input operation of the input unit 4 such as a pointing device Or the four vertices of the partial area are specified by an input operation of the input unit 4 with a cursor, and the partial area is input and stored in the plant growth index measuring device D. The Then, the control processing unit 2 uses the calibration value calculation unit 24 to calculate the second partial region relative growth index corresponding to the second selected place input in step S21 among the target time relative growth indexes obtained in step S2. The second partial region absolute growth index corresponding to the second selected place is extracted from the absolute growth indices at the past time stored in the absolute growth index storage unit 35.

  Then, the control processing unit 2 obtains the second calibration value C2 by the calibration value calculation unit 24 based on the extracted second partial region relative growth index and second partial region absolute growth index, The obtained second calibration value C2 is stored in the calibration value storage unit 36 (S22). More specifically, in the present embodiment, each of the second partial region relative growth index and the second partial region absolute growth index is obtained for each of a plurality of pixels. Similarly, the calibration value calculation unit 24 calculates, for example, the average value B2 of the second partial region relative growth index, calculates the average value A2 of the partial region absolute growth index, and calculates the average of the partial region relative growth index. The ratio of the average value A2 of the partial region absolute growth index to the value B2 is obtained as the second calibration value C2 (C2 = A2 / B2).

  When the second calibration value C2 is obtained by the calibration process of the second aspect as described above, the relative growth index based on the plurality of satellite images at the target time becomes the second calibration value C2 in the process S4 shown in FIG. In step S5 shown in FIG. 4, absolute growth indices based on a plurality of satellite images at the target time determined by the calibration are output.

  In such a calibration process of the second aspect, the plant growth index measurement device D, the plant growth index measurement method, and the plant growth index measurement program use absolute growth indices at past times instead of the plurality of aircraft images. Thus, the second calibration value C2 can be obtained by the above-described process S3, and the target time relative growth index based on a plurality of satellite images at the target time is calibrated by the second calibration value C2 by the above-described process S4. it can. Therefore, the plant growth index measurement device D, the plant growth index measurement method, and the plant growth index measurement program calibrate the target time relative growth index to the second calibration value C2 even when the plurality of aircraft images cannot be acquired. An absolute growth index at the target time can be obtained.

  Next, the calibration process of the third aspect will be described. FIG. 11 is a diagram for explaining the operation of the third aspect in the calibration process shown in FIG.

  In the calibration processing of the first and second aspects described above, there was a partial area in which the ground was reflected in the satellite image, but it can be used as the partial area in the satellite image due to, for example, cloudy weather or fog. It is possible that the earth is not reflected. For this reason, in the calibration process of the third mode, as shown in FIG. 10, the target time (in the example shown in FIG. / 15)) using the absolute growth index obtained in the past (in the example shown in FIG. 10, the previous month and day 10 June (6/5)) and the correspondence between the month and day and the growth index Thus, the absolute growth index at the target time is estimated and obtained from the absolute growth index obtained in the past.

  In such a calibration process of the third aspect, the storage unit 3 is functionally configured with a correspondence information storage unit 38 for storing the correspondence α between the date and the growth index, as indicated by a broken line in FIG. Is done. The correspondence α between the date and the growth index is appropriately created by performing statistical processing or the like on past performance data regarding the plant growing in the field to be measured, and via the input unit 4 or IF The information is stored in advance in the correspondence information storage unit 38 via the unit 1. In the present embodiment, the correspondence relationship α between the date and the NDVI value is stored in the correspondence relationship information storage unit 38 using, for example, a functional expression or a lookup table. Since NDVI correlates with the nitrogen content as is well known, FIG. 11 shows, as an example, a graph (ideal curve) of the correspondence α between the date and the nitrogen content based on past data. .

  In the calibration process of the third aspect, the control processing unit 2 includes a plurality of satellite images at the target time acquired by the IF unit 1 as an example of the satellite image acquisition unit, as indicated by a broken line in FIG. When the ground is not reflected in each, based on the target time, the absolute growth index at the past time stored in the absolute growth index storage unit 35 and the correspondence α stored in the correspondence information storage unit 38, An absolute growth index estimation unit 26 that estimates an absolute growth index at the target time is functionally configured.

  More specifically, in the calibration process of the third aspect, first, in process S1, a predetermined target time (June 15 in the example shown in FIG. 11) is set by imaging the ground from the satellite at each of a plurality of different wavelengths. ), A plurality of satellite images at the target time corresponding to each of the plurality of wavelengths are acquired, and in processing S2, the relative growth index calculation unit 22 performs relative growth index (for example, relative at the target time). NDVI value Vrel (i, j)) is determined.

  The absolute growth index storage unit 35 stores the absolute growth index (for example, the absolute NDVI value Vabs (i, at the past time) in the past time) in the past time (in the example shown in FIG. j)) is stored.

  And in the process S3 and the process S4 shown in FIG. 4, the calibration process and the calculation of the absolute growth index of the third aspect shown in FIG. 11 are executed. In the calibration process of the third aspect, in FIG. 11, the absolute growth index estimation unit 26 determines from the operator (user) whether or not the ground is reflected in each of the plurality of satellite images at the target time acquired in process S1. When the ground is not reflected in each of the plurality of satellite images at the target time acquired through the input unit 4 and acquired in the process S1, the target time relative growth index obtained in the process S2 is incorrect. Based on the target time, the absolute growth index at the past time stored in the absolute growth index storage unit 35, and the correspondence relationship α stored in the correspondence information storage unit 38, the absolute growth index at the target time is calculated. presume. More specifically, the absolute growth index estimation unit 26 obtains a shift amount δ between the absolute growth index Vp and the correspondence α at the past time (in this example, June 5th in the present example) in FIG. The estimated correspondence β is obtained by shifting (shifting) the correspondence α by the obtained deviation δ, and the growth index Ve at the target time (June 15 in this example) is obtained from the estimated correspondence β. To estimate the absolute growth index Vabs at the target time. In the present embodiment, the absolute growth index estimation unit 26 performs such processing for each of all pixels. In this case, the deviation amount δ and the estimated correspondence relationship β are obtained for one appropriately selected pixel among all the pixels, and can be used for each of all the pixels. May be obtained and averaged for a plurality of selected pixels, and may be used for each of all pixels, or may be obtained for one appropriately selected partial region of all pixels, and may be used for each of all pixels. A plurality of appropriately selected partial regions of all pixels may be obtained and averaged and used for each of all the pixels.

  In step S5 shown in FIG. 4, the absolute growth index at the target time thus obtained is output.

  In the calibration process of the third aspect as described above, the plant growth index measuring device D, the plant growth index measurement method, and the plant growth index measurement program are executed by the correspondence relationship α and the absolute growth index estimation unit 26 at the target time. Even when the ground is not reflected in a plurality of satellite images, the absolute growth index at the target time can be obtained.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

D Plant growth index measuring device 1 Interface section (IF section)
2 Control processing unit 3 Storage unit 4 Input unit 5 Output unit 22 Relative growth index calculation unit 23 Partial region absolute growth index calculation unit 24 Calibration value calculation unit 25 Absolute growth index calculation unit 26 Absolute growth index estimation unit 31 Satellite image storage unit 32 Aircraft image storage unit 33 Ambient light information storage unit 34 Relative growth index storage unit 35 Absolute growth index storage unit 36 Calibration value storage unit 37 Selected location information storage unit 38 Corresponding relationship information storage unit

Claims (5)

A satellite image acquisition unit that acquires a plurality of satellite images corresponding to each of the plurality of wavelengths, the ground being imaged from a satellite at each of a plurality of different wavelengths,
A plurality of aircraft images corresponding to each of the plurality of wavelengths obtained by imaging a partial region, which is a partial region in which the ground is reflected in the satellite image acquired by the satellite image acquisition unit, from the aircraft at each of the plurality of wavelengths. An aircraft image acquisition unit for acquiring
An ambient light acquisition unit that acquires a light amount or an incidence rate in ambient light that illuminates the partial area;
Based on the plurality of satellite images acquired by the satellite image acquisition unit, a relative growth index calculation unit for obtaining a relative growth index relatively representing the degree of growth in the plant,
Based on the plurality of aircraft images acquired by the aircraft image acquisition unit and the light quantity or incidence rate acquired by the ambient light acquisition unit, a partial region absolute growth index that absolutely represents the degree of growth in a plant is obtained. A subregion absolute growth index calculator,
The relative growth index corresponding to the partial area of the relative growth index obtained by the relative growth index calculation unit is obtained as a partial area relative growth index, and the obtained partial area relative growth index and the partial area absolute growth are obtained. On the basis of the partial region absolute growth index obtained by the index calculation unit, a calibration value calculation unit for obtaining a calibration value for absoluteizing the partial region relative growth index,
An absolute growth index calculation unit for obtaining an absolute growth index by calibrating the relative growth index obtained by the relative growth index calculation unit with the calibration value obtained by the calibration value calculation unit. Growth index measuring device. The satellite image acquisition unit acquires a plurality of satellite images at the target time corresponding to each of the plurality of wavelengths, captured at a predetermined target time from the satellite as an imaging target at each of the plurality of wavelengths,
In the imaging object, further comprising an absolute growth index storage unit that stores an absolute growth index at a past time obtained at a past time that is past the target time,
The relative growth index calculation unit obtains the relative growth index as a target time relative growth index based on a plurality of satellite images at the target time acquired by the satellite image acquisition unit,
The calibration value calculation unit is a part of the target time relative growth index obtained by the relative growth index calculation unit, which is a partial region in which the ground is reflected in each of the plurality of satellite images at the target time. The second partial area corresponding to the second partial area of the second partial area relative growth index corresponding to the partial area and the absolute growth index at the past time stored in the absolute growth index storage unit. Based on the region absolute growth index, a second calibration value for absoluteizing the second partial region relative growth index is obtained,
The absolute growth index calculation unit calculates the absolute value at the target time by calibrating the target time relative growth index obtained by the relative growth index calculation unit with the second calibration value obtained by the calibration value calculation unit. The plant growth index measuring device according to claim 1, further comprising obtaining a growth index. The satellite image acquisition unit acquires a plurality of satellite images at the target time corresponding to each of the plurality of wavelengths, captured at a predetermined target time from the satellite as an imaging target at each of the plurality of wavelengths,
An absolute growth index storage unit that stores an absolute growth index at a past time determined at a past time that is past the target time in the imaging target;
A correspondence information storage unit for storing the correspondence between the date and the growth index;
When the ground is not shown in each of the plurality of satellite images at the target time acquired by the satellite image acquisition unit, the target time, the absolute growth index at the past time stored in the absolute growth index storage unit, and 3. The absolute growth index estimation unit that estimates an absolute growth index at the target time based on the correspondence relationship stored in the correspondence relationship information storage unit. The plant growth parameter | index measuring apparatus of description. A satellite image acquisition step of acquiring a plurality of satellite images corresponding to each of the plurality of wavelengths, wherein the ground is imaged from the satellite at each of a plurality of different wavelengths.
A plurality of aircraft images corresponding to each of the plurality of wavelengths obtained by imaging a partial region, which is a partial region in which the ground is reflected in the satellite image acquired in the satellite image acquisition step, from each of the plurality of wavelengths. Aircraft image acquisition process to acquire,
An ambient light acquisition step of acquiring a light amount or an incident rate in the ambient light illuminating the partial area;
Based on the plurality of satellite images acquired in the satellite image acquisition step, a relative growth index calculation step for obtaining a relative growth index relatively representing the degree of growth in the plant,
Based on the plurality of aircraft images acquired in the aircraft image acquisition step and the light quantity or incidence rate acquired in the ambient light acquisition step, a partial region absolute growth index that absolutely represents the degree of growth in a plant is obtained. Subregion absolute growth index calculation process,
The relative growth index corresponding to the partial area of the relative growth index calculated in the relative growth index calculation step is determined as a partial area relative growth index, and the partial area relative growth index and the partial area absolute growth determined. Based on the partial region absolute growth index obtained in the index calculation step, a calibration value calculation step for obtaining a calibration value for absoluteizing the partial region relative growth index;
An absolute growth index calculation step of obtaining an absolute growth index by calibrating the relative growth index determined in the relative growth index calculation step with the calibration value determined in the calibration value calculation step. Growth index measurement method. On the computer,
A satellite image acquisition step of acquiring a plurality of satellite images corresponding to each of the plurality of wavelengths, wherein the ground is imaged from the satellite at each of a plurality of different wavelengths.
A plurality of aircraft images corresponding to each of the plurality of wavelengths obtained by imaging a partial region, which is a partial region in which the ground is reflected in the satellite image acquired in the satellite image acquisition step, from each of the plurality of wavelengths. Aircraft image acquisition process to acquire,
An ambient light acquisition step of acquiring a light amount or an incident rate in the ambient light illuminating the partial area;
Based on the plurality of satellite images acquired in the satellite image acquisition step, a relative growth index calculation step for obtaining a relative growth index relatively representing the degree of growth in the plant,
Based on the plurality of aircraft images acquired in the aircraft image acquisition step and the light quantity or incidence rate acquired in the ambient light acquisition step, a partial region absolute growth index that absolutely represents the degree of growth in a plant is obtained. Subregion absolute growth index calculation process,
The relative growth index corresponding to the partial area of the relative growth index calculated in the relative growth index calculation step is determined as a partial area relative growth index, and the partial area relative growth index and the partial area absolute growth determined. Based on the partial region absolute growth index obtained in the index calculation step, a calibration value calculation step for obtaining a calibration value for absoluteizing the partial region relative growth index;
The absolute growth index calculation step for obtaining the absolute growth index by calibrating the relative growth index determined in the relative growth index calculation step with the calibration value determined in the calibration value calculation step,
Plant growth index measurement program.

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