KR100469801B1 - System and Method for Real Time Surveying Ground Control Points of Aerial Photograph - Google Patents

Abstract

PURPOSE: A real time navigation reference point measurement system and a method thereof are provided to control temporal gap between the ground reference point calculation and aerial triangle measurement work using a GPS. CONSTITUTION: According to the real time navigation reference point measurement system, a mobile numerical aviation photo measurement system comprises a pen computer having a module required in an aerial triangle measurement work, and a numerical aviation photo measurement software, and an electronic pen having three dimensional mouse function, and a dedicated mouse port. A RTK(Real Time Kinematic) GPS measurement system comprises a GPS antenna, and a GPS receiver, and a single base station and a number of rover stations. And an observation point sharing system has a digital TRS terminal for communication with a small computer, and an observation sharing server and a client attached in each RTK rover station.

Description

System and method for real time surveying ground control points of aerial photograph

The present invention relates to a real-time navigation control point surveying system using real time kinematic GPS (RTK) GPS and a mobile digital aerial photography survey system, and more specifically, it is possible to measure the precise position of an observation point within a few seconds, Real-time aviation triangulation technique using mobile numerical aerial surveying system is introduced to detect and correct the changes of RTK GPS positioning method, which is likely to change in positioning accuracy according to the reception condition of radio wave and the reception environment of real-time error correction signal. A real-time navigational reference point survey system.

Aerial photogrammetry uses aerial photo cameras mounted on the aircraft to shoot the ground with a certain overlapping level, forms three-dimensional stereoscopic vision using photographs taken from the same area, and observes the shape of various features to make drawings or figures. This is a survey method that writes to a file.

If the positional relationship of the pictures taken in the same area is adjusted to the same as the time of the shooting, and the stereoscopic device is used to adjust the two eyes of the observer to see each picture, the observer can observe the 3D stereoscopic topography. An aerial survey is a survey method developed using this principle. The aerial survey consists of photographing, ground control point surveying, facial expression and stereoscopic vision formation, and feature information extraction of features. Among them, photography and ground control point surveying are performed externally, and the rest is indoor work. to be. Ground control point surveying is the process of surveying the map coordinates of the point clearly shown in the photograph. Until now, static surveying using a two-frequency GPS receiver or surveying using a conventional instrument has been used for field surveying. However, field surveying using these surveying instruments is time-consuming and expensive. It is a significant part of the cost.

The reason why the time-consuming static positioning method is used among the various methods of GPS surveying for the ground control point survey is that the accuracy of the survey results can be verified through the observation of the closed polygon. The GPS static positioning method installs a GPS signal receiver at two points that are to be measured, receives a radio wave from four or more satellites simultaneously for a long time, and then processes the data indoors to calculate the relative distance between the two points. Technique. In the field observation, when constructing a closed polygonal observation network, a geometric condition occurs that the vector sum of three observation bases forming a triangle must be zero. When the condition is satisfied, the entire baseline You can analyze the magnitude of the errors involved and verify the reliability of the survey results. For this reason, GPS static positioning method is mainly used in spite of the disadvantage that it takes much time and cost to survey aerial control point.

The new positioning method that has been introduced in the field of GPS positioning since the late 1990s is the real time kinematic GPS positioning method. It is a technique that can calculate the precise distance between two points immediately after observation by using wireless radio communication to transfer the necessary part of data from one observation receiver to the other receiver. Although the positioning accuracy is inferior, it is an excellent observation method because it can measure the position in a short time in real time.

However, such a real-time mobile positioning method is not used for surveying reference point measurement because the position measurement is performed in a short time, but the positioning accuracy fluctuates due to the reception state of radio waves. Although indicators can be used to evaluate positioning accuracy at the time of observation, it is difficult to establish a rigorous accuracy evaluation criteria such as the closed polygon satisfaction condition in static positioning method, so it is difficult to devise a method to completely eliminate such accuracy fluctuations. it's difficult. In addition, since the observation method itself is a radial observation centered on one reference station, only one baseline is observed, and it is very difficult to form an observation network constituting a closed polygon.

On the other hand, the digital photogrammetry system was developed by improving the existing mechanical and analytical photogrammetry system used for aerial surveys. For aerial surveys, the location of two stereoscopic images that are duplicated in the same area must be adjusted so that the positional relationship between them is the same as when they were photographed. Can be. Existing photogrammetry systems use aerial photographic film in analog method, use mechanisms for reproducing positional relationship, and consequently have disadvantages that involve considerable weight and volume of machinery.

The digital photogrammetry system is a digitization of the existing photogrammetry systems. Instead of aerial photographic film, digital photogrammetric data is used instead of aerial photographic film. It is designed to perform by calculation. The principle of stereoscopic vision formation has also been changed to a numerical formula, in which two aerial photographs are alternately displayed on the screen at a frequency of 60 KHz, and one eye can see only one image through stereoscopic glasses that react differently to each frequency band. Make sure to see the real world in a way that makes sense. In addition to this method, there are various methods of implementing the numerical instance of the numerical entity.

Digital photogrammetry systems do not require aerial photographic films or separate mechanical devices to form the real world, but only high-performance computers and electronic devices used to implement digital image data and stereoscopic vision. In this digital imaging system, the relative positional relationship between two aerial photographs can be calculated by simply selecting the same point on two overlapping aerial photographs, and selecting the position of the ground reference point on the photograph and inputting coordinates. Up to the absolute position of the three-dimensional model based on the map coordinate system can be calculated.

The aerial photographing process currently used is aerial photographing → ground reference point surveying using GPS static positioning method → GPS coordinate data analysis to calculate ground reference point coordinates → ground control point performance and map production using aerial surveying equipment Is done. This process is technically proven and has sufficient accuracy to be applied to the production of national digital topographic maps. However, the ground reference point survey part using GPS static positioning method has sufficient accuracy to be used for aerial surveys, but the observation time per reference point is long and requires a lot of time and manpower. In addition, GPS data processing, verification, and performance calculations are performed after all observations are completed. If the data processing results are poor, it is often necessary to re-evaluate after the observation ends. The disadvantage is that there is a lack of linkage with the aerial survey part that is actually used.

The above problems are caused by separation of the aerial triangulation process that defines the positional relationship between aerial photographs using the ground reference point survey and the ground reference point in the aerial survey process.

The present invention has been made to solve the problems of the prior art as described above, the main object of the present invention is to remove the time interval between the observation operation of the ground reference point surveying using GPS and the observation data processing operation to simultaneously observe the data It is possible to calculate processing and performance, and to use RTK GPS positioning method and mobile digital aerial photography system to eliminate the time gap between ground control point performance calculation using GPS and aerial triangulation work. To provide.

Figure 1 shows the configuration of a mobile digital aerial photography survey system of the present invention.

FIG. 2 shows a state in which a stereoscopic mirror is mounted in FIG. 1.

Figure 3 shows the configuration of the RTK GPS surveying system of the present invention.

Figure 4 shows the configuration of the observation point sharing system of the present invention.

Figure 5 shows the configuration of a database for observation point sharing server of the present invention.

Figure 6 shows the internal expression operation (A) and the junction setting operation (B) as a preliminary preparation of the ground reference point observation using the real-time navigation reference point surveying system according to the present invention.

7 shows the configuration of a GPS observation network for surveying and calculating reference station coordinates to be used as a base station for RTK GPS surveying in field work.

8 shows a real-time ground control point surveying sequence of the present invention.

Figure 9 illustrates the verification of the accuracy of the surveying reference points surveyed in real time using the air triangulation function included in the mobile digital photogrammetry system.

In order to achieve the above object, the present invention is a real time kinematic global positioning system (RTK) positioning method and a real-time navigation reference point surveying system using a mobile digital aerial photography survey system,

(a) A mobile numerical aerial photography survey system with the following components:

(i) a pen computer embodying some modules necessary for aerial triangulation of a digital aerial photography survey system;

(ii) the ability to display photographed data taken over the area, to select the location on the photographic data corresponding to the field observation point, to input measured coordinates, and to perform aerial triangulation; Digital aerial photography surveying software having a function of verifying the accuracy of coordinates;

(iii) an electronic pen in which an implementation part of the entity and a three-dimensional mouse function are implemented; And

(iv) a dedicated mouse terminal portion;

(b) GPS antennas for receiving radio waves from GPS satellites, GPS receivers for storing received data and processing various data, RFM modems for transmitting and receiving error correction signals, and various additional devices used for power supply and connection between devices. RTK GPS surveying system composed of a single base station and a plurality of mobile stations including; And

(c) a point of view sharing system comprising a viewpoint sharing server installed near a RTK base station, equipped with a small computer and equipped with a digital TRS terminal for communication, and a terminal type client attached to each RTK mobile station. It provides a real-time navigational control point surveying system.

In the present invention, the observation point sharing server comprises: (i) an aerial photograph strip information table; (ii) mobile station receiver information table; (iii) an aerial photo table; And (iv) a relational database consisting of a viewpoint table.

The present invention also provides a survey method for aerial photography, characterized in that using the real-time navigation reference point survey system.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

The system of the present invention is composed of a mobile digital aerial photographing system, an RTK GPS surveying system, and an observation point sharing system for sharing survey results observed by various GPS mobile stations.

1 is a block diagram of a mobile digital aerial photography surveying system designed to apply the coordinates surveyed at the survey site directly to the aerial photographic surveying system, as shown, the overall configuration of a mobile digital aerial photography surveying system according to the present invention It consists of a pen computer, digital aerial photography survey software, a three-dimensional mouse control terminal, an electronic pen for three-dimensional pointer adjustment, a wireless data modem for connection to a point-of-view sharing system, a USB port for GPS connection, and a stereoscopic instance.

The pen computer selected and implemented some of the modules required for aerial triangulation, among other features of the digital photogrammetry system, with the addition of several additional devices needed to form the entity. The software for numerical aerial photography surveying, which is the core of the system, is designed to run smoothly on a pen computer, and the above software can display overlapped photographed data for the area and the image data corresponding to the field observation point. Selecting a location, inputting measured coordinates, and performing aerial triangulation to verify the accuracy of the measured coordinates. Another main component of the system is an electronic pen for controlling a three-dimensional pointer and a dedicated mouse terminal portion in which an implementation part at the time of implementation and a three-dimensional mouse function are implemented. In order to accurately display the field observation point on the over-photographed image, it is efficient to display the scene at a time after forming the actual vision. Therefore, the three-dimensional pointer adjustment electronic pen is able to form a real vision immediately in the field by using the stereoscopic stereoscopic method, and the three-dimensional mouse function is implemented to display in consideration of the height. As shown in FIG. 1, when the rotation button attached to the pen is rotated, the mouse pointer is moved in the height direction when the mouse pointer is formed, and the current position can be accurately displayed on the picture using this function. In addition to the electronic pen, the three-dimensional mouse adjustment function also attaches to the pen computer so that the height of the mouse pointer can be adjusted through the fingers of the hand holding the computer.

3 is a schematic diagram of an RTK GPS surveying system in charge of a real-time ground control point survey portion, wherein the entire RTK GPS surveying system includes a single base station and a plurality of mobile stations. The exact coordinates of the base station are installed at a point already known or at a national reference point, and the mobile station is installed at a point to be surveyed but moved to another point after the observation is completed. The base station and the mobile station are both a GPS antenna for receiving radio waves from a GPS satellite, a GPS receiver for storing received data and processing various data, an RFM modem for supplying error correction signals, a power supply, and various devices used for connection between devices. It consists of an additional device. In order to calculate the exact distance between the base station and the mobile station and to calculate the position of the mobile station using the calculated distance, carrier phase data information is transmitted from the base station to the mobile station firstly, the exact coordinates of the base station, and secondly, GPS satellite signals. Should be. The mobile station receives this information through the RFM modem and precisely calculates the position of the mobile station through real time ambiguity resolution.

4 is a block diagram of a viewpoint sharing system for sharing survey results observed by various mobile stations, and includes a single viewpoint sharing server installed near a base station and terminal-type clients attached to each mobile station. A digital trunked radio system (TRS) scheme is used for communication between the single viewpoint sharing server and clients of each mobile station. The GPS survey portion consists of a single base station and a plurality of mobile stations, which perform surveys in different regions. When applying the surveyed results to a mobile digital photogrammetry system, the coordinates surveyed at each mobile station must be collected and the collected coordinates must be available to the digital photogrammetry system equipped at each mobile station. The aerial photographic stereoscopic models built into each digital photogrammetry system cover the entire map production area, and more accurate calculations can be performed when more ground control point coordinates are widely distributed. The coordinates surveyed at each mobile station are collected.

Terminals attached to each mobile station transmit observation point items included in the mobile digital photogrammetry system connected to the calculated coordinates after the observation point survey is performed to the observation point sharing server installed near the base station. The viewpoint sharing server registers the received coordinates, compares all the registered viewpoints with the transmitted viewpoint items, and transmits all newly registered viewpoint information to the terminal. In this way, the mobile stations share information from the observation points and can perform more accurate aerial triangulation. The observation point sharing server installed near the base station is equipped with a small computer and a digital TRS terminal for communication. The viewpoint sharing server manages the viewpoint information transmitted from the mobile stations, as shown in Fig. 5, i) an aerial photograph strip information table, ii) a mobile station receiver information table, iii) an aerial photograph table, and iv) a viewpoint table. Contains a relational database consisting of:

The process of obtaining a ground reference point using the real-time navigational reference point surveying system according to the present invention includes a preliminary preparation work, a site preparation work, and a real-time ground reference point surveying and aerial triangulation work.

The preliminary work is to input data into the mobile digital photogrammetry system before leaving the field observation. First, convert the aerial film into numerical image data using an aerial photograph scanner and convert the generated image data into digital photographs. Enter it into the survey system. After inputting the image data into the system, after generating a project file to comprehensively manage the aerial photographs and ground control point information and other related information to be used, and after the project file is generated, the internal expression work, as shown in Figure 6a Is carried out. Next, as shown in Fig. 6B, in order to define the positional relationship between the two overlapping pictures, a joint point setting operation is performed. Junction setting work is performed on all overlapping pictures taken by selecting the same point from two overlapping pictures, targeting pictures taken in the direction of aircraft flight, and overlapping in the direction perpendicular to the aircraft flight direction. Do the same with the pictures. Once the junction entry is complete, all image data, project files and other relevant data will be copied into the mobile digital photogrammetry systems that will be used in the field.

In order to use the RTK GPS positioning method selected as the ground control point, first calculate the exact coordinates of the point where the base station is to be installed. As shown in FIG. 7, the exact coordinates of the point where the base station is to be installed are equally divided over the entire work site, and three or more points to be used as the base station of the RTK GPS survey are selected and surveyed using the static positioning method. An integrated linking observation with the national control point is performed for the calculation. When the post-observation data is processed, the location of the base station is calculated based on the location of the national reference point by using the coordinates of the national reference point.

Real-time ground reference point surveying and aerial triangulation work is carried out using a mobile station consisting of a GPS equipment, a mobile digital photogrammetry system, a wireless data communication modem as shown in FIG. 8 shows a real-time ground control point survey sequence, as shown in the figure, after moving to a survey target point displayed in an aerial photograph and displaying the current observation point in digital image data by using a real-time formation function on a mobile digital photogrammetry system. do. When you start an RTK GPS survey after displaying a viewpoint, the system begins to measure the position in 1-5 seconds, and after a few seconds or minutes the position measurement is complete if the indicator of positioning accuracy is satisfactory. The results are automatically sent to the digital photogrammetry system. The position of the ground reference point is displayed on the two numerical image data constituting the real city, and after the coordinates are input, aerial triangulation is performed. Digital photogrammetry defines the positional relationship between digital images by means of aerial triangulation, in which the center of exposure of the aerial vibrator, the point indicated on the digital image data, and the actual point on the ground must be co-linear. Based on the conditions, the adjustment calculation is performed, and the precision of the ground reference point coordinates is calculated.

An on-site observer can perform an RTK GPS survey and then check the results using the aerial photogrammetry technique of the mobile digital photogrammetry system and run the survey until satisfactory accuracy is obtained. FIG. 9 illustrates an example of verifying the accuracy of surveyed reference points measured in real time by using an aerial triangulation function included in a mobile digital photogrammetry system, and VX, VY, and VZ items of FIG. Corresponds to the elevation, the precision of each coordinate is calculated accurately. If the newly measured ground control point performance is found to be satisfactory as a result of aerial triangulation, register the observation point sharing server using the observation point sharing system. In addition, when there is a point that is observed by another mobile station and registered in the server, the data is downloaded and input to the mobile digital photogrammetry system used. After performing aerial triangulation once again using the newly surveyed performance and ground control point information downloaded from the observation point sharing server, if there is no problem in the performance, move to the next observation point.

As described above in detail specific parts of the present invention, those skilled in the art, these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described in detail above, the real-time navigation control point surveying system using the RTK GPS positioning method and the mobile digital photogrammetry system according to the present invention supports a mobile digital photogrammetry system that can be used for verifying the accuracy of surveying results. By enabling real-time ground control point surveys, the time required for ground control point surveys can be greatly reduced, reducing site survey costs and time. In addition, by performing aerial triangulation directly at the ground control point survey site, it is possible to check the accuracy of the real-time models configured for the aerial survey to prevent the delay of the process.

Claims (3)

In real-time navigation control point surveying system using RTK GPS and mobile numerical aerial survey system, (a) A mobile numerical aerial photography survey system with the following components: (i) a pen computer embodying some modules necessary for aerial triangulation of a digital aerial photography survey system; (ii) the ability to display photographed data taken over the area, to select the location on the photographic data corresponding to the field observation point, to input measured coordinates, and to perform aerial triangulation; Digital aerial photography surveying software having a function of verifying the accuracy of coordinates; (iii) an electronic pen in which an implementation part of the entity and a three-dimensional mouse function are implemented; And (iv) a dedicated mouse terminal portion; (b) GPS antennas for receiving radio waves from GPS satellites, GPS receivers for storing received data and processing various data, RFM modems for transmitting and receiving error correction signals, and various additional devices used for power supply and connection between devices. RTK GPS surveying system composed of a single base station and a plurality of mobile stations including; And (c) Viewpoint sharing, located near the RTK base station, equipped with a digital TRS terminal for communication with a small computer and comprising a relational database consisting of an aerial photograph strip information table, a mobile station receiver information table, an aerial photograph table and a viewpoint table. A real-time navigation control point surveying system comprising a viewpoint sharing system comprising a server and clients of terminal type attached to each RTK mobile station. delete A method for surveying aerial photographs using a real-time navigation reference point surveying system according to claim 1.