SU1529048A1 - Photometer for measuring characteristics of vegetative cover - Google Patents

Abstract

This invention relates to spectrophotometry and can be used in agriculture. The purpose of the invention is to expand the number of measured parameters of vegetation cover. The sensor of the Photometer has two bodies 1 and 2 mounted on one base 3, with the blend 12 of one of the bodies limiting the viewing angle to 15 °, and the blend of the second body is made in the form of a nozzle consisting of two flat disks 13 and 14 and a diaphragm 15 located successively along the course of radiation, limiting reception of radiation by two circular cones with vertex angles of 90 and 95 °. The photometer allows for measuring the difference between the photodetectors of the first and second buildings to measure the mass of only the vertical components of the vegetation cover, to recognize the type, to establish the phase of development of agricultural crops, and also to determine the mass of green weeds among cultivated plants. 1 il.

Description

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(21) 4313148 / 30-25

(22) 10/06/87

(46) 12/15/89. -Bull No. 46

(71) All-Union Scientific Research Institute of Agricultural Meteorology

(72) A.A.Gen and A, F.Konov

(53) 535.24 (088 „8)

(56) Kondratyev K.Ya. et al. Aerospace investigations of soil and vegetation L; Hydrometeoizdat, 1986, glo 2.

USSR Author's Certificate 1245893, class G 01 J 1/04, 1986.

(54) PHOTOMETER FOR MEASUREMENT OF PLANT COVER CHARACTERISTICS

(57) The invention relates to spectrophotometry and can be used in agriculture. The purpose of the invention is to expand the number of dimensions e67

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parameters of vegetation cover. The photometer sensor has two bodies 1 and 2 mounted on one base 3, and the hood 12 of one of the bodies limits the viewing angle to 15 ° and the second body hood is designed as a nozzle consisting of two flat disks 13 and 14 and a diaphragm 15 located successively along the course of radiation, limiting reception of radiation by two circular cones with vertex angles of 90 and 95 °. The photometer allows for measuring the difference between the photodetectors of the first and second buildings, measuring only the masses of the vertical components of the vegetation cover, identifying the type, determining the phase of development of agricultural crops, and determining the mass of green weeds among cultivated plants. 1 il.

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The invention relates to devices for measuring the intensity and spectral composition of the radiation, can be used for photometric measurements in agriculture.

The aim of the invention is to increase the number of measured vegetation parameters by changing the characteristics of the angular sensitivity and simultaneity of measurements in two different directions. The drawing shows the date, / chick photometer, vertical section.

The photometer sensor consists of two housings 1 and 2 fixed rigidly on a common base 3 ". Each of the housings 1 and 2 contains a correction element 4, a rotor 5 on which a light-scattering, opaque cap 6 with openings are located, and a conical light-scattering closure - a cavity, a beam-splitting element 7, a light filter 8 on the IR spectral range, a light filter 9 on the K-spectral range, photodetectors of the corresponding ranges 10 and 11. In front of the body 1 there is a cylindrical hood 12 that limits the angle of view 15. Before the nozzle body 2 is mounted consisting of opaque shields in the form of a disk 13, diaphragm 14 and 15 which confine, nachivaet receiving radiation angle two circular cones with apex angles of 90 and 95 °.

The photometer works as follows.

First, the photometer is configured. The rotors 5 of both housings are installed so that radiation from the entire celestial hemisphere enters the photodetectors of the housings 1 and 2. In this position, the difference of signals at the output of the electronic unit (not shown) is zero.

After adjustment, the photometer is put into operation. The rotors 5 rotate 180 ° and radiation from the underlying surface in an angle limited by a cone with an apex of 15 ° (blend 12), and radiation from the underlying surface in a gap (on drawing) between the screens 13, 14 and the diaphragm 15 “The equality of the signals between the devices established during the adjustment varies in proportion to the mass of the vertical components of the vegetation cover.

The essence of the invention is as follows.

The ratio of the spectral luminance coefficient (CQW) of vegetation in the IR spectral range to CQW in the K spectral range depends on the mass of vegetation cover, the measurement direction and the spatial arrangement of photocells in vegetation cover .. Under other equal conditions, the CQW ratio for vegetation with horizontal phytoelements does not depend on the direction of measurement, for vegetation cover with vertically arranged phytoelements (vertical components of mass) increase It grows with increasing viewing angle. Consequently, according to the difference of signals in two fixed directions, we can judge the mass of only the vertical components of the mass of vegetation cover. The choice of angles of view of the photometer was made on the basis of information analysis of measurement data of indicatrices of different types of vegetation cover of high spatial resolution. The best in terms of informativeness is the combination of two angles of view 15 and a solid angle limited by two circular cones with angles of apex 90 and 95. This combination of angles of view allows you to increase information on the structure of vegetation by 20-30% compared with other possible variants of observation angles. Simultaneous observation in two different directions is provided. that the photometer is equipped with two parallel operating devices for converting directional radiation into scattered radiation with different field-forming nozzles.

The device allows to measure the mass of only the vertical components of the vegetation by the difference of signals between the photodetectors of buildings 1 and 2, identify the type of vegetation, determine the phases of development of agricultural crops, and determine the mass of green weeds among cultivated plants differing in the arrangement of leaves.

According to the indications of only carpus with a field angle of 15 °, it is possible to determine the total mass of vegetation cover.

Claims (1)

Invention Formula In order to increase the number of measured parameters of vegetation cover, the photometer contains an additional body identical to the first case, with a correction element and a rotor identical to the correction element and the rotor installed respectively on the first case and inside it , both bodies are rigidly connected to each other in such a way that their inlets are of the same orientation, the hood of the first building is made with a photometer to measure the characteristics of the vegetation cover containing the building mustache with the first and second inlets oriented in opposite directions, a correction element in the form of an opaque cap with openings, mounted on a J5 lindrical and limiting field From the point of view of the photodetectors with an angle of 15, the blend of the second body is made in the form of a nozzle consisting of an additional body mounted along the axis of the hole, oriented identical to the second hole of the first frame. the first inlet, a hood mounted on the second inlet, a rotor containing a light-scattering cavity and a beam-splitting element with optically coupled photodetectors of the red and infrared spectral ranges, the rotor being installed inside the housing with the possibility of alternating optical communication of the beam-splitting element through the light scattering a cavity with the first and second inlets, as well as an electronics unit, connected to both photodetectors, about tl and h apus, two opaque screens a disc-shaped diaphragm and, disposed between them and confining corporal 25 acceptance angle of radiation ny two circular cones with apex angles of 90 and 95 °, and the electronics unit is connected with the two additional photodetectors rotor housing. 90486 In order to increase the number of measured parameters of vegetation cover, the photometer contains an additional body identical to the first case, with a correction element and a rotor identical to the correction element and the rotor installed respectively on the first case and inside it , both bodies are rigidly connected to each other in such a way that their inlets are of the same orientation, the hood of the first body is made cylindrical and field bounding a disk, two opaque screens in the form of a disk and a diaphragm installed between them, limiting the solid angle of radiation intake by two circular cones with apexes of 90 and 95 °, and the electronics unit is connected to both rotor photodetectors of the additional housing.