On-orbit scanning precision test system for scanning telescope

Abstract

The invention discloses an in-orbit scanning precision test system for a scanning telescope. The in-orbit scanning precision test system comprises a detector, a telescope scanning mechanism, a scanning controller, a video processor, a management controller, a satellite data transmission system and a ground data receiving system, wherein the scanning controller is used for collecting real-time angle information of the telescope; the management controller is used for receiving a GPS time code and a second pulse signal sent by a satellite; the video processor is used for transmitting the imaging synchronization pulse to the detector; receiving image data, and inputting the real-time angle information, the GPS time code and the second pulse signal into the image data to obtain an image and auxiliary data; the detector is used for performing synchronous integral control under the triggering of the imaging synchronous pulse to obtain image data; and the ground data receiving system is used for extracting real-time angle information of each row of images in the images and the auxiliary data, and obtaining scanning precision according to the real-time angle information of each row of images. According to the invention, the scanning precision of the scanning telescope can be monitored in orbit, and the scanning precision of an in-orbit system is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of space remote sensing, and in particular relates to an on-orbit scanning accuracy testing system for a scanning telescope. Background Art

[0002] The space telescope scanning imaging system adopts the overall rotation scanning method of the telescope, and can realize large field of view target imaging through a small-scale detector; the telescope scanning imaging system uses two motors to drive a telescope system and a half-angle reflector to rotate in one direction at a uniform speed respectively. The two are synchronized in phase to collect ground radiation information within the scanning field of view. The ground radiation information is converged to the focal planes of different channels at the back end after passing through the color separation plate and the relay optical system of each channel. The focal plane of each channel converts the radiation information into image information and transmits it to the satellite data transmission system, thereby transmitting the imaging information back to the ground.

[0003] However, there is no technology in the prior art that can monitor the accuracy of the scanning system on-orbit, so it is impossible to directly obtain the scanning accuracy data on-orbit. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and provide an on-orbit scanning accuracy test system for a scanning telescope, so as to monitor the scanning accuracy of the scanning telescope system on-orbit and ensure the scanning accuracy of the on-orbit system.

[0005] The object of the present invention is achieved through the following technical solutions: a scanning telescope on-orbit scanning accuracy test system, comprising: a detector, a telescope scanning mechanism, a scanning controller, a video processor, a management controller, a satellite data transmission system and a ground data receiving system; wherein the scanning controller is connected to the telescope scanning mechanism; the scanning controller controls the rotation of the telescope scanning mechanism; the scanning controller collects the real-time angle information of the telescope, and sends the real-time angle information and imaging synchronization pulse of the telescope to the video processor; the management controller receives the GPS time code and second pulse signal sent by the satellite and forwards the GPS time code and second pulse signal to the video processor; the video processor receives the real-time angle information, imaging synchronization pulse, The detector receives the imaging synchronization pulse, performs synchronous integration control under the triggering of the imaging synchronization pulse to obtain the image data, and transmits the image data to the video processor; the satellite data transmission system receives the image and the auxiliary data and sends the image and the auxiliary data to the ground data receiving system; the ground data receiving system receives the image and the auxiliary data, extracts the real-time angle information of each row of the image in the image and the auxiliary data, and obtains the scanning accuracy of the telescope system on orbit according to the real-time angle information of each row of the image.

[0006] In the above-mentioned scanning telescope on-orbit scanning accuracy test system, the scanning controller controls the telescope scanning mechanism to rotate 360° at a uniform speed.

[0007] In the above-mentioned scanning telescope on-orbit scanning accuracy test system, the scanning controller controls the telescope scanning mechanism to rotate 360° at a fixed angular rate ω; the scanning controller rotates at a preset period t col The real-time angle information θ of the telescope is collected and sent to the video processor through the serial interface.

[0008] In the above-mentioned scanning telescope on-orbit scanning accuracy test system, the video processor receives the imaging synchronization pulse sent by the scanning controller, and triggers the detector to start scanning at a preset period t0 at the falling edge of the imaging synchronization pulse. int Perform repeated integration.

[0009] In the above-mentioned scanning telescope on-orbit scanning accuracy test system, the preset period t col and the preset period t int The relationship is: col ≤1 / 5*t int .

[0010] In the above scanning telescope on-orbit scanning accuracy test system, the scanning accuracy of the telescope system on-orbit is obtained according to the real-time angle information of each line of image, including: setting n*t int is the minimum time unit; where n is the number of frames of image data; the angle travel value of the minimum time unit is calculated row by row according to the real-time angle information of each row of image, and the angle series [Δθ1, Δθ2, Δθ3, ... Δθ m ]; where Δθ1 is the first minimum time unit angular travel value, Δθ2 is the second minimum time unit angular travel value, Δθ3 is the third minimum time unit angular travel value, and Δθ m is the angle travel value of the mth minimum time unit, and m is the number of minimum time units in the imaging cycle; calculate the angle series [Δθ1, Δθ2, Δθ3, ... Δθ m The standard deviation of ] rel ;According to the angular rate ω and the minimum time unit, the standard value of the angular travel at the nominal speed is obtained. std ; According to the standard deviation δ rel And the standard value of angular travel at nominal speed δ std Obtain the scanning accuracy of the telescope system on orbit.

[0011] In the on-orbit scanning accuracy test system of the above-mentioned scanning telescope, the standard value of the angular travel at the nominal speed is δ std It is obtained by the following formula:

[0012] δ std =ωnt int .

[0013] In the above-mentioned scanning telescope on-orbit scanning accuracy test system, the on-orbit scanning accuracy of the telescope system is obtained by the following formula:

[0014]

[0015] Among them, ε is the scanning accuracy of the telescope system on orbit.

[0016] In the on-orbit scanning accuracy test system of the scanning telescope, the angle sequence [Δθ1, Δθ2, Δθ3, ... Δθ m ] Whether the angle data is valid includes:

[0017] According to the preset period t col and the preset period t int Get the real-time angle sampling times N within the line period;

[0018] According to the real-time angle sampling times N, the angular rate ω and the preset period t within the line period col Get the standard line angle difference Δλ;

[0019] Calculate the difference between the real-time angle data of two adjacent frames of images, which is recorded as the angle data difference series [Δλ1, Δλ2, Δλ3, ... Δλ m-1 ]; where Δλ1 is the angle difference between the second frame image and the first frame image, Δλ2 is the angle difference between the third frame image and the second frame image, Δλ3 is the angle difference between the fourth frame image and the third frame image, and Δλ m-1 is the angle difference between the m-th frame image and the m-1-th frame image;

[0020] The angle data difference series [Δλ1, Δλ2, Δλ3, ... Δλ m-1 The elements in ] are compared with Δλ in turn. If it is less than Δλ, the element is invalid and replaced by Δλ.

[0021] In the above-mentioned scanning telescope on-orbit scanning accuracy test system, the real-time angle sampling times N within the line period is obtained by the following formula:

[0022]

[0023] The standard line angle difference Δλ is obtained by the following formula:

[0024] Δλ=Nωt col .

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention obtains image auxiliary data through a ground data receiving system to quickly and in real time obtain the scanning accuracy of the telescope system, and effectively corrects the control parameters of the scanning control system according to the calculation results to ensure the scanning accuracy of the on-orbit system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0028] Figure 1 It is a structural block diagram of an on-orbit scanning accuracy test system for a scanning telescope provided by an embodiment of the present invention;

[0029] Figure 2 This is a timing diagram of scanning accuracy test data provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] Figure 1 1 is a structural block diagram of an on-orbit scanning accuracy test system for a scanning telescope provided by an embodiment of the present invention. Figure 1 As shown, the scanning telescope on-orbit scanning accuracy test system includes: a detector, a telescope scanning mechanism, a scanning controller, a video processor, a management controller, a satellite data transmission system and a ground data receiving system; wherein,

[0032] The scanning controller is connected to the telescope scanning mechanism; the scanning controller controls the rotation of the telescope scanning mechanism;

[0033] The scanning controller collects the real-time angle information of the telescope and sends the real-time angle information and imaging synchronization pulse of the telescope to the video processor;

[0034] The management controller receives the GPS time code and the pulse-per-second signal sent by the satellite and forwards the GPS time code and the pulse-per-second signal to the video processor;

[0035] The video processor receives real-time angle information, imaging synchronization pulses, GPS time codes and second pulse signals, and transmits the imaging synchronization pulses to the detector; receives image data, inserts the real-time angle information, GPS time codes and second pulse signals into the image data to obtain images and auxiliary data, and transmits the images and auxiliary data to the satellite data transmission system;

[0036] The detector receives an imaging synchronization pulse, performs synchronous integration control under the triggering of the imaging synchronization pulse to obtain image data, and transmits the image data to the video processor;

[0037] The satellite data transmission system receives images and auxiliary data and sends the images and auxiliary data to the ground data receiving system;

[0038] The ground data receiving system receives images and auxiliary data, extracts real-time angle information of each row of images in the images and the auxiliary data, and obtains the scanning accuracy of the telescope system on track according to the real-time angle information of each row of images.

[0039] The scanning controller controls the telescope scanning mechanism to rotate 360 ​​degrees at a constant speed, collects the real-time angle information of the telescope at a fixed frequency, and sends it to the video processor; the management controller receives the GPS time code and second pulse signal sent by the satellite and forwards it to the video processor. The video processor receives the real-time angle information, imaging synchronization pulse, GPS time code and second pulse signal, performs synchronous integration control on the detector, and enters the latest real-time angle information of each integration into the image and auxiliary data. The satellite data transmission system sends the image and auxiliary data to the ground data receiving system; through the real-time angle information of each line of image extracted from the image auxiliary data of the ground data receiving system, the scanning accuracy of the telescope system on orbit is obtained through calculation methods.

[0040] The scanning controller controls the telescope scanning mechanism to rotate 360° at a fixed angular rate ω. The scene image within the 360° field of view is introduced into each channel detection unit through the optical path. The scanning controller rotates the telescope scanning mechanism at a period t col The real-time angle θ of the telescope is collected, and the real-time angle θ obtained at each collection point is sent to the video processor through the serial interface.

[0041] The video processor receives the imaging synchronization pulse sent by the scanning controller, and triggers the detection unit to start scanning at a period of t0 at the falling edge of the imaging synchronization pulse. int Repeat the integration and after each integration starts, the latest telescope real-time angle θ in the current cache is int Enter the image auxiliary data of the current line.

[0042] The satellite data transmission system sends images and auxiliary data to the ground receiving system, extracts real-time angle information from the auxiliary data, and calculates the scanning accuracy of the system.

[0043] like Figure 1 The scanning controller shown collects the real-time angle period t col Confirmation method:

[0044] Calculate the scanning real-time angle acquisition period t col :t col ≤1 / 5*t int .

[0045] like Figure 2 As shown, the scanning accuracy of the telescope system on orbit is obtained based on the real-time angle information of each row of images:

[0046] Set to n*t int is the minimum time unit; where n is the number of frames of image data;

[0047] According to the real-time angle information of each row of images, the angle travel value of the minimum time unit is calculated row by row, and the angle series [Δθ1, Δθ2, Δθ3, ... Δθm ]; where Δθ1 is the first minimum time unit angular travel value, Δθ2 is the second minimum time unit angular travel value, Δθ3 is the third minimum time unit angular travel value, and Δθ m is the angle travel value of the mth minimum time unit, and m is the number of minimum time units in the imaging cycle;

[0048] Find the angle series [Δθ1, Δθ2, Δθ3, ... Δθ m The standard deviation of ] rel ;

[0049] According to the angular rate ω and the minimum time unit, the standard value of the angular travel δ at the nominal speed is obtained std ;

[0050] According to the standard deviation δ rel And the standard value of angular travel at nominal speed δ std Obtain the scanning accuracy of the telescope system on orbit.

[0051] Standard value of angular travel at nominal speed δ std It is obtained by the following formula: std =ωn·t int .

[0052] The scanning accuracy of the telescope system on orbit is obtained by the following formula:

[0053]

[0054] Among them, ε is the scanning accuracy of the telescope system on orbit.

[0055] Usually, ε≤0.3% is required.

[0056] like Figure 2 As shown, the method for confirming invalid data is:

[0057] According to the preset period t col and the preset period t int Calculate the number of real-time angle sampling times N within the line cycle: N = t int / t col ;

[0058] According to the real-time angle sampling times N, the angular rate ω and the preset period t within the line period col Calculate the standard line angle difference Δλ, Δλ=N*ω*t col ;

[0059] Starting from the first row, the difference between the real-time angle data of two adjacent rows is calculated row by row, which is recorded as the series [Δλ1, Δλ2, Δλ3, ... Δλ m-1]; among them, Δλ1=Δθ2-Δθ1; Δλ2=Δθ3-Δθ2; Δλ3=Δθ4-Δθ3; Δλ m-1 =Δθ m -Δθ m-1 ; Δλ1 is the angle difference between the second frame image and the first frame image, Δλ2 is the angle difference between the third frame image and the second frame image, Δλ3 is the angle difference between the fourth frame image and the third frame image, Δλ m-1 is the angle difference between the m-th frame image and the m-1-th frame image;

[0060] Let the sequence [Δλ1, Δλ2, Δλ3,...Δλ m-1 ] are compared with Δλ in turn. If Δλ is less than Δλ, the element is removed and replaced by Δλ. The calculation is continued according to the accuracy method to obtain the final scanning accuracy data. For example, if Δλ3 is less than Δλ, Δλ3 is replaced by Δλ, then Δλ3=Δθ4-Δθ3 is replaced by Δλ=Δθ4-Δθ3, then the angle series [Δθ1, Δθ2, Δθ3, ... Δθ m ] is replaced by Δλ+Δθ3.

[0061] This embodiment uses the image auxiliary data obtained by the ground data receiving system to quickly and in real time obtain the scanning accuracy of the telescope system, and based on the calculation results, effectively corrects the control parameters of the scanning control system to ensure the scanning accuracy of the on-orbit system.

[0062] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A scanning telescope on-orbit scanning accuracy test system, characterized in that include: Detector, telescope scanning mechanism, scanning controller, video processor, management controller, satellite data transmission system and ground data receiving system; among them, The scanning controller is connected to the telescope scanning mechanism; the scanning controller controls the rotation of the telescope scanning mechanism; The scanning controller collects the real-time angle information of the telescope and sends the real-time angle information and imaging synchronization pulse of the telescope to the video processor; The management controller receives the GPS time code and the pulse-per-second signal sent by the satellite and forwards the GPS time code and the pulse-per-second signal to the video processor; The video processor receives real-time angle information, imaging synchronization pulses, GPS time codes and second pulse signals, and transmits the imaging synchronization pulses to the detector; receives image data, inserts the real-time angle information, GPS time codes and second pulse signals into the image data to obtain images and auxiliary data, and transmits the images and auxiliary data to the satellite data transmission system; The detector receives an imaging synchronization pulse, performs synchronous integration control under the triggering of the imaging synchronization pulse to obtain image data, and transmits the image data to the video processor; The satellite data transmission system receives images and auxiliary data and sends the images and auxiliary data to the ground data receiving system; The ground data receiving system receives images and auxiliary data, extracts real-time angle information of each row of images in the images and the auxiliary data, and obtains the scanning accuracy of the telescope system on track according to the real-time angle information of each row of images.

2. The scanning telescope on-orbit scanning accuracy test system according to claim 1, characterized in that: The scanning controller controls the telescope scanning mechanism to rotate 360° at a constant speed.

3. The scanning telescope on-orbit scanning accuracy test system according to claim 1, characterized in that: The scanning controller controls the telescope scanning mechanism to rotate 360 ​​degrees at a fixed angular rate ω. col The real-time angle information θ of the telescope is collected and sent to the video processor through the serial interface.

4. The scanning telescope on-orbit scanning accuracy test system according to claim 3, characterized in that: The video processor receives the imaging synchronization pulse sent by the scanning controller, and triggers the detector at the falling edge of the imaging synchronization pulse at time t0 to start scanning at a preset period t int Perform repeated integration.

5. The scanning telescope on-orbit scanning accuracy test system according to claim 4, characterized in that: Preset period t col and the preset period t int The relationship is: col ≤1 / 5*t int .

6. The scanning telescope on-orbit scanning accuracy test system according to claim 4, characterized in that: The scanning accuracy of the telescope system on orbit is obtained based on the real-time angle information of each line of image, including: Set to n*t int is the minimum time unit; where n is the number of frames of image data; According to the real-time angle information of each row of images, the angle travel value of the minimum time unit is calculated row by row to obtain the angle series; Find the standard deviation δ of the angle series rel ; According to the angular rate ω and the minimum time unit, the standard value of the angular travel δ at the nominal speed is obtained std ; According to the standard deviation δ rel And the standard value of angular travel at nominal speed δ std Obtain the scanning accuracy of the telescope system on orbit.

7. The scanning telescope on-orbit scanning accuracy test system according to claim 6, characterized in that: Standard value of angular travel at nominal speed δ std It is obtained by the following formula: d std =ω·n·t int 。 8. The scanning telescope on-orbit scanning accuracy test system according to claim 6, characterized in that: The scanning accuracy of the telescope system on orbit is obtained by the following formula: Among them, ε is the scanning accuracy of the telescope system on orbit.

9. The scanning telescope on-orbit scanning accuracy test system according to claim 6, characterized in that: Judging whether the angle data in the angle series is valid includes: According to the preset period t col and the preset period t int Get the real-time angle sampling times N within the line period; According to the real-time angle sampling times N, the angular rate ω and the preset period t within the line period col Get the standard line angle difference Δλ; Calculate the difference between the real-time angle data of two adjacent frames of images, and record it as the angle data difference series; The elements in the angle data difference series are compared with Δλ in turn. If the angle data difference is less than Δλ, the element is invalid and is replaced by Δλ.

10. The scanning telescope on-orbit scanning accuracy test system according to claim 9, characterized in that: The real-time angle sampling times N within a line period is obtained by the following formula: The standard line angle difference Δλ is obtained by the following formula: Δλ=N·ω·t col 。

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