A method for determining forward and reverse light working arc segments of a spacecraft sensor

Abstract

The application relates to a method for determining a sunward and anti-sunward working arc section of a spacecraft sensor, which converts the sunward and anti-sunward problem of the spacecraft sensor into a visibility problem of a spacecraft antenna and an observation constellation based on constraints, converts the working condition of the sensor into a constraint of the spacecraft antenna, and thus quickly obtains a working arc section meeting the requirements by using a visibility analysis tool of an orbit toolbox. The application adopts a system toolbox (STK) to model a spacecraft orbit and attitude and a spacecraft sensor, establishes an angle relationship between a light axis normal plane of the spacecraft sensor and a sun vector, sets constraint parameters corresponding to sunward and anti-sunward of the sensor, uses an Access analysis tool to complete the sunward and anti-sunward working arc section of the sensor meeting the task requirements, and outputs an analysis report, thereby providing support for a spacecraft on-orbit task analysis and test process design.

Description

Technical Field

[0001] This invention relates to a method for determining the forward and reverse light operating arc of a spacecraft sensor, which can be used for analyzing the operating window of a spacecraft sensor during its on-orbit operation and providing support for spacecraft mission analysis. Background Technology

[0002] Spacecraft sensors are generally subject to strong operational constraints while in orbit. For example, sensors for target detection and tracking must operate in illuminated areas, and sunlight must illuminate the target and enter the sensor's field of view through reflection from the target, i.e., the conditions of direct sunlight must be met.

[0003] To conduct spacecraft mission analysis and design, it is necessary to calculate the forward and reverse light operating arcs of specific sensors to obtain the operating window of a particular sensor that meets its own needs. Based on this, the coupling of multiple types of sensors is considered to obtain spacecraft mission windows that meet various requirements, thus supporting the implementation and operation of spacecraft missions.

[0004] Traditional sensor operating arc calculations require establishing an orbital dynamics model, combining spacecraft attitude, the relationship between the sun and the earth, and other conditions, and using complex geometric derivations and formulas for calculation. This is inefficient, inflexible, prone to errors, and does not utilize the coupled analysis of multiple sensor integrated windows. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the complexity of traditional sensor operating arc segment analysis and propose a method for determining the forward and reverse light operating arc segment of a spacecraft sensor. This method transforms the problem of analyzing the forward and reverse light of a spacecraft sensor into a constraint-based visibility problem of spacecraft antennas and telemetry and control resources. By converting the operating conditions of the sensor into spacecraft antenna constraints, the visibility analysis tools in the orbit toolbox can be used to quickly obtain the operating arc segment that meets the requirements.

[0006] The solution of this invention is: a method for determining the forward and reverse light operating arc segment of a spacecraft sensor, comprising the following steps:

[0007] Step 1: Based on the spacecraft's mission orbit and attitude, sensor characteristics and parameters, use the STK system toolbox to establish the spacecraft's mission orbit model and mission attitude model to achieve scenario creation;

[0008] Step 2: Add an antenna model to the spacecraft and set the antenna parameters;

[0009] Step 3: Based on the scenario created in Step 1, establish an observation constellation that is visible to the spacecraft antenna at all times;

[0010] Step 4: Convert the sensor's forward and reverse lighting conditions into sign constraints on the angle between the antenna normal and the solar vector: the forward lighting condition is converted to an angle between the antenna normal and the solar vector that is less than or equal to 0, and the reverse lighting condition is converted to an angle between the antenna normal and the solar vector that is greater than or equal to 0; and set the extreme values ​​of the angle between the antenna normal and the solar vector under forward lighting or reverse lighting conditions.

[0011] Step 5: After adding the constraint described in Step 4 that the angle between the antenna normal and the solar vector is less than or equal to 0 to the antenna model, perform visibility calculations for the antenna and the observation constellation. Extract the visible time period data of the antenna and the observation constellation from the visibility analysis results, which is the working arc segment of the sensor in the direction of sunlight.

[0012] Step 6: After adding the constraint described in Step 4 that the angle between the antenna normal and the solar vector is greater than or equal to 0 to the antenna model, perform the visibility calculation of the antenna and the observation constellation again. Extract the visible time period data of the antenna and the observation constellation from the visibility analysis results, which is the backlight working arc segment of the sensor.

[0013] Furthermore, the spacecraft mission orbit model described in step 1 adopts the orbit recursive model provided by STK software.

[0014] Furthermore, the spacecraft mission attitude model described in step 1 adopts the attitude model provided by STK software, including a three-axis Earth-to-ground stable attitude model and a Sun-to-the-world orientation attitude model.

[0015] Furthermore, the antenna model described in step 2 uses the Sensor model provided by STK software, and the antenna parameters set include: antenna type, antenna orientation, and half-beam range; wherein, the antenna type is set to conical, the antenna orientation points towards the zenith, and the half-beam range is 90 degrees.

[0016] Furthermore, the establishment of the observation constellation described in step 3 is achieved through the constellation construction function of the STK software: a blank constellation model is created, and taking advantage of the global coverage provided by three equally spaced geostationary orbit satellites, three geostationary orbit satellites are added to the blank constellation model using the STK software. The three geostationary orbit satellites are evenly distributed in geostationary orbit, thus completing the construction of the observation constellation.

[0017] Furthermore, the method for creating the angle between the antenna normal perpendicular plane and the solar vector in step 4 is as follows: using the Analysis Workbench tool of STK software, with the solar vector as the reference vector, create the angle between the solar vector and the antenna normal perpendicular plane, select the angle type as line-plane angle, and determine the angle type as signed type.

[0018] Furthermore, step 4 converts the sensor's forward and reverse lighting conditions into a sign constraint of the angle between the antenna normal and the solar vector. This is achieved by setting the Sun and Vector properties in the Constraints property of the antenna model: first, the illumination characteristics in the Sun property are set to the illuminated area; then, the angle variable in the Vector property is set to the angle between the antenna normal and the solar vector, and the range of the angle under forward or reverse lighting conditions is filled in.

[0019] Furthermore, in steps 5 and 6, the visibility calculation between the antenna and the observation constellation is performed by first establishing a chain model between the observation constellation and the spacecraft antenna using STK software. The visibility between the antenna and the observation constellation is then calculated using the calculation function of STK software. The visibility analysis results are output using the Report function of the chain model and the Complete Chain Access template. The visibility analysis results include the visible time period between the antenna model and the observation constellation.

[0020] Furthermore, the extreme value of the angle between the antenna normal plane and the solar vector described in step 4 is 90° under backlighting conditions and -90° under frontlighting conditions.

[0021] The advantages of this invention compared to the prior art are:

[0022] (1) This invention transforms the problem of analyzing the working arc segment of a spacecraft sensor in both forward and reverse light into a problem of visibility of antenna and telemetry and control resources based on constraints. It can be easily implemented using mature software tools, thus solving the drawback of traditional sensor working arc segment calculation using complex orbital dynamics geometric relationship formulas.

[0023] (2) By setting the maximum and minimum values ​​of the angle between the solar vector and the antenna normal under both direct and reverse lighting conditions, this invention improves the flexibility, speed and accuracy of the analysis of the working arc segment of the spacecraft sensor under both direct and reverse lighting conditions. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the spacecraft sensor in the forward and reverse light direction according to the present invention.

[0025] Figure 2 This is a flowchart illustrating the analysis process of the present invention. Detailed Implementation

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] The objective of this invention is to analyze the forward and reverse lighting operating arcs of a spacecraft sensor, specifically the operating time period when the angle between the solar vector and the sensor's optical axis perpendicular to the light source meets the requirements. First, the angle between the solar vector and the sensor's optical axis perpendicular to the light source is defined. Symbols, such as Figure 1 As shown. When the solar vector and the sensor optical axis vector are on the same side of the optical axis perpendicular plane, the definition is... The sign is positive, and the opposite is negative. Therefore, when analyzing the working arc segment of the sensor in the direction of light, constraints are required. When analyzing the backlight operating arc of the sensor, constraints are required.

[0028] This invention transforms the target problem into a constraint-based visibility problem between spacecraft antennas and telemetry and control resources. A telemetry and control antenna is established in the zenith direction of the spacecraft, and a geostationary orbit constellation visible to this antenna at all times is constructed. By setting the solar vector angle constraint for the telemetry and control antenna that is consistent with the front and back lighting conditions of the sensor, the working arc segment of the sensor can be obtained.

[0029] like Figure 1 As shown, the specific analytical steps of this invention include:

[0030] Step 1: Based on the spacecraft's mission orbit and attitude, sensor characteristics and parameters, use the STK system toolbox to establish the spacecraft's mission orbit model and mission attitude model to achieve scenario creation;

[0031] Step 2: Add an antenna model to the spacecraft and set the antenna parameters;

[0032] Step 3: Based on the scenario created in Step 1, establish an observation constellation that is visible to the spacecraft antenna at all times;

[0033] Step 4: Convert the sensor's forward and reverse lighting conditions into sign constraints on the angle between the antenna normal and the solar vector: the forward lighting condition is converted to an angle between the antenna normal and the solar vector that is less than or equal to 0, and the reverse lighting condition is converted to an angle between the antenna normal and the solar vector that is greater than or equal to 0; and set the extreme values ​​of the angle between the antenna normal and the solar vector under forward lighting or reverse lighting conditions.

[0034] Step 5: After adding the constraint described in Step 4 that the angle between the antenna normal and the solar vector is less than or equal to 0 to the antenna model, perform visibility calculations for the antenna and the observation constellation. Extract the visible time period data of the antenna and the observation constellation from the visibility analysis results, which is the working arc segment of the sensor in the direction of sunlight.

[0035] Step 6: After adding the constraint described in Step 4 that the angle between the antenna normal and the solar vector is greater than or equal to 0 to the antenna model, perform the visibility calculation of the antenna and the observation constellation again. Extract the visible time period data of the antenna and the observation constellation from the visibility analysis results, which is the backlight working arc segment of the sensor.

[0036] (1) In step 1, the scenario creation in this invention uses STK software. The spacecraft mission orbit model uses the orbit recursive model provided by STK software, such as the J2 perturbation model, or the orbit data obtained from external simulation calculations can be imported. The spacecraft mission attitude model uses the attitude types provided by STK software, such as the three-axis Earth-stabilized attitude model and the Sun-oriented attitude model, or the attitude data obtained from external simulation calculations can be imported.

[0037] (2) In step 2, the spacecraft antenna model in this embodiment of the invention adopts the Sensor model provided by STK software, the antenna type is set to cone, the antenna orientation is pointing towards the zenith, and the half-beam range is 90 degrees.

[0038] (3) In step 3, the observation constellation established in this invention needs to be visible to spacecraft at all times. This is achieved by using the constellation construction function of STK software: create a blank constellation model, and use the characteristic that three equally spaced geostationary orbit satellites can cover the globe. Then, use STK software to add three geostationary orbit satellites to the blank constellation model. The three geostationary orbit satellites are evenly distributed in geostationary orbit, thus completing the construction of the observation constellation.

[0039] (4) In step 4, the present invention establishes the angle between the antenna solar vector and the normal vertical plane using the Analysis Workbench tool of the antenna object in the STK software. When creating the angle between the solar vector and the antenna normal vertical plane, the angle type is selected as line-plane angle, the reference vector is the sun vector, the reference plane is the antenna normal vertical plane, and the angle type is determined to be signed.

[0040] (5) In step 4, the present invention converts the front-light and back-light conditions of the sensor into a sign constraint of the angle between the antenna normal and the solar vector. This is achieved by setting the Sun and Vector properties in the Constraints attribute of the antenna model: first, the illumination characteristics in the Sun property are set to the illuminated area; then, the angle variable in the Vector property is set to the angle between the solar vector and the antenna normal, and the maximum and minimum values ​​of the angle are set. In this embodiment, the angle range under front-light conditions is -90° to 0°, and the angle range under back-light conditions is 0° to 90°.

[0041] (6) In steps 5 and 6, the visibility analysis between the antenna and the observation constellation is conducted in this invention. First, a chain model between the observation constellation and the spacecraft antenna is established using STK software. The visibility between the antenna and the observation constellation is calculated using the calculation function of STK software. Using the Report function of the chain model, the Complete Chain Access template is selected to output the visibility analysis results. The visibility analysis results include the visible time period between the antenna model and the observation constellation when the angle between the antenna normal plane and the solar vector is in the range of -90° to 0° or 0° to 90°. The visible time period data between the antenna and the observation constellation is extracted, which is the working arc segment of the sensor under front lighting or backlighting conditions.

[0042] This invention is also applicable to the analysis of the working arc segment of multiple sensor constraint superposition. Based on the same method, multiple antennas are created, and constraints that meet the working requirements of the sensors are set for each antenna. Finally, the visibility results of each antenna are summarized and analyzed to determine the working arc segment of multiple sensor constraint superposition.

[0043] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for determining the forward and reverse light operating arc segment of a spacecraft sensor, characterized in that, The method includes the following steps: Step 1: Based on the spacecraft's mission orbit and attitude, sensor characteristics and parameters, use the STK system toolbox to establish the spacecraft's mission orbit model and mission attitude model to achieve scenario creation; Step 2: Add an antenna model to the spacecraft and set the antenna parameters; Step 3: Based on the scenario created in Step 1, establish an observation constellation that is visible to the spacecraft antenna at all times. The establishment of the observation constellation is achieved through the constellation building function of STK software: create a blank constellation model, and take advantage of the global coverage characteristic of three equally spaced geostationary orbit satellites. Use STK software to add three geostationary orbit satellites to the blank constellation model. The three geostationary orbit satellites are evenly distributed in geostationary orbit to complete the construction of the observation constellation. Step 4: Convert the sensor's forward and reverse lighting conditions into a sign constraint on the angle between the antenna normal and the solar vector: the forward lighting condition is converted to an angle between the antenna normal and the solar vector that is less than or equal to 0, and the reverse lighting condition is converted to an angle between the antenna normal and the solar vector that is greater than 0; and set the extreme values ​​of the angle between the antenna normal and the solar vector under forward lighting or reverse lighting conditions. Step 5: After adding the constraint described in Step 4 that the angle between the antenna normal and the solar vector is less than or equal to 0 to the antenna model, perform visibility calculations for the antenna and the observation constellation. Extract the visible time period data of the antenna and the observation constellation from the visibility analysis results, which is the working arc segment of the sensor in the direction of sunlight. Step 6: After adding the constraint described in Step 4 that the angle between the antenna normal and the solar vector is greater than 0 to the antenna model, perform the visibility calculation of the antenna and the observation constellation again. Extract the visible time period data of the antenna and the observation constellation from the visibility analysis results, which is the backlight working arc segment of the sensor.

2. The method for determining the forward and reverse light operating arc segment of a spacecraft sensor according to claim 1, characterized in that, The spacecraft mission orbit model described in step 1 uses the orbit recursion model provided by STK software.

3. The method for determining the forward and reverse light operating arc segment of a spacecraft sensor according to claim 1, characterized in that, The mission attitude model described in step 1 uses the attitude model provided by STK software, including a three-axis ground-stabilized attitude model and a solar-oriented attitude model.

4. The method for determining the forward and reverse light working arc segment of a spacecraft sensor according to claim 1, characterized in that, The antenna model described in step 2 uses the Sensor model provided by STK software. The antenna parameters set include: antenna type, antenna orientation, and half-beam range. The antenna type is set to conical, the antenna orientation points towards the zenith, and the half-beam range is 90 degrees.

5. The method for determining the forward and reverse light working arc segment of a spacecraft sensor according to claim 1, characterized in that, The method for creating the angle between the antenna normal and the solar vector in step 4 is as follows: using the Analysis Workbench tool of STK software, with the solar vector as the reference vector, create the angle between the solar vector and the antenna normal, select the angle type as line-plane angle, and determine the angle type as signed.

6. The method for determining the forward and reverse light operating arc segment of a spacecraft sensor according to claim 1, characterized in that, Step 4 describes converting the sensor's forward and reverse lighting conditions into a sign constraint on the angle between the antenna normal and the solar vector. This is achieved by setting the Sun and Vector properties in the Constraints property of the antenna model: First, set the illumination characteristics in the Sun property to the illuminated area. Then, set the angle variable in the Vector property to the angle between the antenna normal and the solar vector, and fill in the range of angle values ​​under forward or reverse lighting conditions.

7. The method for determining the forward and reverse light working arc segment of a spacecraft sensor according to claim 1, characterized in that, The visibility calculation of the antenna and the observation constellation described in steps 5 and 6 first involves using STK software to establish a chain model between the observation constellation and the spacecraft antenna. The visibility between the antenna and the observation constellation is then calculated using the calculation function of the STK software. The visibility analysis results are output using the Report function of the chain model and the Complete Chain Access template. The visibility analysis results include the visible time period between the antenna model and the observation constellation.

8. The method for determining the forward and reverse light working arc segment of a spacecraft sensor according to claim 1, characterized in that, The extreme value of the angle between the antenna normal plane and the solar vector in step 4 is 90° under backlight conditions and -90° under frontlight conditions.

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