CN111634445A - Low-orbit satellite large-width detection vertical orbit swinging scanning method - Google Patents

Low-orbit satellite large-width detection vertical orbit swinging scanning method Download PDF

Info

Publication number
CN111634445A
CN111634445A CN201911358782.5A CN201911358782A CN111634445A CN 111634445 A CN111634445 A CN 111634445A CN 201911358782 A CN201911358782 A CN 201911358782A CN 111634445 A CN111634445 A CN 111634445A
Authority
CN
China
Prior art keywords
satellite
orbit
calculating
image
imaging
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201911358782.5A
Other languages
Chinese (zh)
Inventor
曹永奎
倪淑燕
廖育荣
李兆铭
李磊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Peoples Liberation Army Strategic Support Force Aerospace Engineering University
Original Assignee
Peoples Liberation Army Strategic Support Force Aerospace Engineering University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Peoples Liberation Army Strategic Support Force Aerospace Engineering University filed Critical Peoples Liberation Army Strategic Support Force Aerospace Engineering University
Priority to CN201911358782.5A priority Critical patent/CN111634445A/en
Publication of CN111634445A publication Critical patent/CN111634445A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B64G1/244—Spacecraft control systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/10—Artificial satellites; Systems of such satellites; Interplanetary vehicles
    • B64G1/1021—Earth observation satellites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/10—Artificial satellites; Systems of such satellites; Interplanetary vehicles
    • B64G1/1021—Earth observation satellites
    • B64G1/1028—Earth observation satellites using optical means for mapping, surveying or detection, e.g. of intelligence
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B64G1/244—Spacecraft control systems
    • B64G1/245—Attitude control algorithms for spacecraft attitude control

Landscapes

  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • General Physics & Mathematics (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Evolutionary Computation (AREA)
  • Navigation (AREA)

Abstract

The invention provides a low-orbit satellite large-width detection vertical orbit swinging scanning method, which comprises the following specific processes: calculating the angular velocity of the satellite; (II) calculating the central position of the image in the satellite scanning process; (III) calculating the position of the satellite when the satellite points to the central position of the image based on the angular velocity of the satellite; fourthly, calculating an expected attitude of the satellite when the satellite points to the central position of the image according to the position of the satellite; and controlling the satellite according to the expected attitude to realize large-width detection vertical orbit swinging. The method can realize vertical orbit swing scanning of the satellite, fully utilizes the overhead time and improves the agile imaging efficiency.

Description

Low-orbit satellite large-width detection vertical orbit swinging scanning method
Technical Field
The invention relates to a low-orbit satellite large-width detection vertical orbit swinging scanning method, and belongs to the technical field of spacecraft control.
Background
The space-based platform detection is utilized to continuously observe the ground environment, the regional safety and the like, and the method has the advantages of strong sustainability, wide reachable range and the like. The low-orbit satellite platform can achieve higher resolution, and the formed constellation can achieve very high revisitation rate, so that the low-orbit satellite platform is the first choice for a plurality of earth observation satellites. However, the low orbit satellite earth observation field of view is limited, and the detection range needs to be widened, so that the detection capability of a large-range area is improved.
The wide-range imaging can image a wider area when the satellite passes by one time, the imaging efficiency of the satellite is improved, the satellite top-passing time is effectively utilized, and the cost is reduced. The satellite attitude change is utilized to adjust the sensor pointing direction, and the realization of satellite agile imaging is an effective way for expanding the imaging width. The posture change tracks in the agile imaging process are different, and the influence on the imaging performance is obvious. The method is characterized in that a proper posture track is designed, so that limited overhead time is fully utilized, the target area is subjected to wide imaging greatly, and the method is one of the problems to be solved for further improving the imaging efficiency.
Currently, the way for realizing large-width imaging by a low-orbit agile satellite adopts multi-strip scanning along the track direction: in the overhead time, a strip is formed by scanning in a posture maneuvering mode, the posture is adjusted after the scanning is finished, the next strip is scanned, and finally the large-width imaging is realized by splicing. This approach requires allocating a portion of the time for the satellite attitude maneuver during the over-the-top time, which reduces the detection capability of the agile satellite.
Disclosure of Invention
In view of the above, the invention provides a large-width detection vertical orbit swinging method for a low-orbit satellite, which can realize vertical orbit swinging of the satellite, fully utilize the overhead time and improve the efficiency of agile imaging, so that the limited time can be fully utilized in the overhead time of the agile satellite.
The technical scheme for realizing the invention is as follows:
a low-orbit satellite large-width detection vertical orbit swinging method comprises the following specific processes:
calculating the angular velocity of the satellite;
(II) calculating the central position of the image in the satellite scanning process;
(III) calculating the position of the satellite when the satellite points to the central position of the image based on the angular velocity of the satellite;
fourthly, calculating an expected attitude of the satellite when the satellite points to the central position of the image according to the position of the satellite; and controlling the satellite according to the expected attitude to realize large-width detection vertical orbit swinging.
Further, the calculation process of the step (two) of the present invention is:
calculating the number m of imaging strips and the number n of times of imaging required in each strip according to the width of the camera and the size of a target area;
the longitude and latitude coordinates of four vertexes of the target area are assumed to be respectively: (Lo)E,LaE)、(LoF,LaF)、(LoG,LaG) And (Lo)H,LaH) In the case of the p (p.ltoreq.m) th and q (q.ltoreq.n) th images, the optical axis of the camera on the satellite should point to the point (Lo)p,q,Lap,q)
When p is an odd number, the calculation formula is as follows:
Figure BDA0002336636330000021
when p is an even number, the calculation formula is as follows:
Figure BDA0002336636330000031
the satellite camera optical axis should point to a point (Lo)p,q,Lap,q) Namely the central position of the image in the satellite scanning process.
Further, the step (three) of the present invention is:
suppose that the field angle at the time of the first imaging is γ0The elevation point and the geocentric angle gamma of the satellitep,qShowing the position of the satellite at the p-th strip and the q-th image,
γp,q＝γ0+ω[(p-1)m+q]。
advantageous effects
The invention can realize vertical rail swinging, thereby fully utilizing the overhead time, improving the agile imaging efficiency, fully exerting the capability of the satellite on-orbit task and improving the benefit.
Drawings
FIG. 1 is a schematic diagram of vertical swing scanning for large width detection.
FIG. 2 is a geometrical relationship analysis of satellite side-sway imaging.
Fig. 3 is a schematic diagram of roll and pitch angle calculations.
FIG. 4 shows a view stitching approach for vertical sweep.
FIG. 5 shows a schematic view of along-rail swipe imaging.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.
As shown in fig. 1, when the satellite reaches the upper part of the target area, the satellite starts to detect from one corner of the area, and after the detection is completed, the field of view is adjusted to move for the next detection, so that two detection fields can be spliced into a larger field of view, and thus a vertical rail strip-shaped area is formed repeatedly; the process is then repeated in reverse until the entire area is covered. In the process, the satellite controls the load direction through the attitude, and the whole process is realized.
Firstly, the height of a satellite orbit is assumed to be h km, and the single detection width of a satellite point under a carrying detector is s-a × b km2The maximum allowable inclination angle of the camera is α rad, and the size of a detection target area is S-l × wkm2Where l represents the along-rail length and w represents the perpendicular rail width; the radius of the earth is R.
Calculating satellite velocity and angular velocity
When the satellite passes by once, according to the load imaging capacity, the load points to the target area to start imaging scanning by adjusting the pitch angle when the target area is not reached. When leaving the area, imaging can be achieved within a certain range.
If the complete coverage of the specified area is ensured in the large-width swinging detection of the satellite, the imaging is started from the corner of the specified range, and the highest imaging efficiency can be ensured. In FIG. 2, A is the position of the satellite, C is the position of the sub-satellite point of A, B is the center position of the first image, and D is the first imageThe central point position of the sweep period is located in the track of the point under the satellite. A. the1，A2The orbit height is h km, O represents the geocentric, and R represents the radius of the earth.
From the sine theorem we can derive:
Figure BDA0002336636330000041
so that:
Figure BDA0002336636330000042
due to the fact that the & lt OBA & gt is & lt pi-alpha
Figure BDA0002336636330000043
This is B, C point-to-ground opening angle.
When calculating the roll angle phi, similar to the above process, see the left diagram of fig. 3, where the known condition is BD ═ w km, governed by the cosine theorem:
Figure BDA0002336636330000051
the roll angle value is therefore:
Figure BDA0002336636330000052
for the pitch axis, see the right diagram of fig. 3, it can be obtained by the cosine theorem of the triangle:
Figure BDA0002336636330000053
wherein the introduction of the beta is the change of the angle representation caused by the change of the orbit coordinate system, and the pitch angle can be calculated as follows:
Figure BDA0002336636330000054
substituting the specific numerical value to calculate the size of the product.
The computed satellite may advance the geocentric angle:
Figure BDA0002336636330000055
in one transit, the opening angle of the track section around the geocentric, which can allow the load to work, is as follows:
Figure BDA0002336636330000056
according to the satellite motion law, the satellite velocity and the angular velocity of the satellite at the height of h km can be calculated as follows:
Figure BDA0002336636330000057
Figure BDA0002336636330000058
wherein G isE＝GME＝3.986×1014m3/s2And is the gravitational constant.
In the step, the maximum task time t of one transit can be further calculatedm：
Figure BDA0002336636330000061
Secondly, calculating the central position of the image in the scanning process
I.e. the center of the image at each scout imaging is calculated. As shown in fig. 4, EFGH is the four vertices of an area with known latitude and longitude, and the area is parallel to the locus of the sub-satellite points. The number (p, q) in the figure indicates the q-th image on the p-th band.
Calculating the number of imaging strips at least as follows according to the width of the camera and the size of the target area:
Figure BDA0002336636330000062
wherein w represents the vertical rail width and a represents the field of view width of the camera;
ceil (×) in the formula represents rounding up, and similarly, the number of images required in each band is:
Figure BDA0002336636330000063
wherein, l represents the length along the track, b represents the length of the field of view of the camera;
therefore, m × n imaging is required, and the images are uniformly distributed in the region. As shown in fig. 4, p denotes the imaging order of the bands, and q denotes the imaging order in the bands. The coordinates of the center point at each imaging can be obtained by calculation. And in the low-latitude area, the longitude and latitude are approximately calculated through the interpolation difference.
The longitude and latitude coordinates of four vertexes of the target area are assumed to be respectively: (Lo)E,LaE)、(LoF,LaF)、(LoG,LaG) And (Lo)H,LaH). In the p (p ≦ m) th band, q (q ≦ n) th image, the satellite camera optical axis should point to the point (Lo)p,q,Lap,q) I.e., the center position of the image, the scanning directions are different when p is odd and even.
When p is an odd number, the calculation formula is as follows:
Figure BDA0002336636330000071
when p is an even number, the calculation formula is as follows:
Figure BDA0002336636330000072
thirdly, calculating the position of the satellite when pointing to the central point of the image
Assuming that the orbit parameters of the satellite are known, the earth center corresponding to the position of the satellite at the lifting point along the running direction of the satellite in the orbit plane is usedOpening angle gammap,qThe position of the satellite in the p (p is less than or equal to m) th strip and the q (q is less than or equal to n) th image is shown, and the field angle in the first imaging is assumed to be gamma0Then, there are:
γp,q＝γ0+ω[(p-1)m+q](17)
in the formula, ω is calculated from formula (11).
Fourthly, calculating the expected attitude of the satellite pointing to the central position
And transforming longitude and latitude coordinates in a geographic coordinate system into a representation under an orbit coordinate system through a typical coordinate transformation relation:
Figure BDA0002336636330000073
wherein i0For orbital inclination, gamma-gammap,qFrom the coordinates (x)o,yo,zo) Obtaining an expected attitude angle phip,q，θp,q，
Figure BDA0002336636330000074
The calculation method is as follows:
Figure BDA0002336636330000081
through the four steps, the change condition of the expected value of the satellite attitude angle in the whole imaging task process can be calculated, and the satellite attitude control is completed according to the expected attitude given by the formula (19), so that the satellite can realize vertical-orbit wide scanning and large-range imaging.
In a traditional agile imaging mode of pushing and sweeping along a track, as shown in fig. 5, the distance between the end point of the previous strip and the start point of the next strip is far, large-angle attitude maneuver needs to be performed between imaging strips, and a large amount of time is occupied for attitude adjustment. The invention adopts a vertical rail swinging mode, the distance between the end point of the previous strip and the start point of the next strip is short, large-angle maneuvering is not needed between the strips, the overhead time can be fully utilized, the efficiency of agile imaging is improved, the capability of the satellite on-orbit task is fully exerted, and the benefit is improved.
Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, it will be apparent to those skilled in the art that various modifications may be made without departing from the principles of the invention and these are considered to fall within the scope of the invention.

Claims (3)

1. A low-orbit satellite large-width detection vertical orbit swinging method is characterized by comprising the following specific processes:
calculating the angular velocity of the satellite;
(II) calculating the central position of the image in the satellite scanning process;
(III) calculating the position of the satellite when the satellite points to the central position of the image based on the angular velocity of the satellite;
fourthly, calculating an expected attitude of the satellite when the satellite points to the central position of the image according to the position of the satellite; and controlling the satellite according to the expected attitude to realize large-width detection vertical orbit swinging.
2. The method for wide-range detection of vertical sweep of low earth orbit satellite according to claim 1, wherein the calculation process of the step (two) is as follows:
calculating the number m of imaging strips and the number n of times of imaging required in each strip according to the width of the camera and the size of a target area;
the longitude and latitude coordinates of four vertexes of the target area are assumed to be respectively: (Lo)E,LaE)、(LoF,LaF)、(LoG,LaG) And (Lo)H,LaH) In the case of the p (p.ltoreq.m) th and q (q.ltoreq.n) th images, the optical axis of the camera on the satellite should point to the point (Lo)p,q,Lap,q)
When p is an odd number, the calculation formula is as follows:
Figure FDA0002336636320000011
when p is an even number, the calculation formula is as follows:
Figure FDA0002336636320000012
the satellite camera optical axis should point to a point (Lo)p,q,Lap,q) Namely the central position of the image in the satellite scanning process.
3. The method for detecting the vertical swing of the low-earth-orbit satellite with the large width according to claim 2, wherein the step (three) is as follows:
suppose that the field angle at the time of the first imaging is γ0The elevation point and the geocentric angle gamma of the satellitep,qShowing the position of the satellite at the p-th strip and the q-th image,
γp,q＝γ0+ω[(p-1)m+q]。
CN201911358782.5A 2019-12-25 2019-12-25 Low-orbit satellite large-width detection vertical orbit swinging scanning method Pending CN111634445A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911358782.5A CN111634445A (en) 2019-12-25 2019-12-25 Low-orbit satellite large-width detection vertical orbit swinging scanning method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911358782.5A CN111634445A (en) 2019-12-25 2019-12-25 Low-orbit satellite large-width detection vertical orbit swinging scanning method

Publications (1)

Publication Number Publication Date
CN111634445A true CN111634445A (en) 2020-09-08

Family

ID=72325044

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911358782.5A Pending CN111634445A (en) 2019-12-25 2019-12-25 Low-orbit satellite large-width detection vertical orbit swinging scanning method

Country Status (1)

Country Link
CN (1) CN111634445A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112849434A (en) * 2021-01-28 2021-05-28 中国科学院微小卫星创新研究院 Method for calculating over-top time of circular orbit satellite and application

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112849434A (en) * 2021-01-28 2021-05-28 中国科学院微小卫星创新研究院 Method for calculating over-top time of circular orbit satellite and application
CN112849434B (en) * 2021-01-28 2024-05-14 中国科学院微小卫星创新研究院 Computing method and application of circular orbit satellite overhead moment

Similar Documents

Publication Publication Date Title
CN107505948B (en) Attitude adjustment method for imaging along curve strip in agile satellite locomotive
CN107152926B (en) A kind of satellite quickly rotates super large breadth sweeping imaging method
CN103983254B (en) The motor-driven middle formation method of a kind of novel quick satellite
CN103217987B (en) Agile satellite dynamic imaging posture adjustment method
CN110515078B (en) Wave position design method for airspace coverage
CN102229362B (en) Attitude compensation method of agile satellite imagery in reverse push-broom mismatch
CN108449129B (en) Global multi-target all-day real-time monitoring system and method
CN108965708B (en) Imaging system and method for realizing wide-area search of large visual field by using small visual field camera
CN103134492B (en) Agile imaging satellite linear scan strip pre-generating method based on point target and satellite three-axis gesture rapid determining method
CN105549008B (en) A kind of parameter optimization method of the big spaceborne Spotlight SAR Imaging system of strabismus of variable element
CN111523209B (en) Land resource satellite calibration orbit planning and reference load orbit optimization method
CN112348242B (en) Static orbit remote sensing satellite region division and observation method
CN111667100B (en) Agile satellite single-rail multi-point target three-dimensional imaging task planning method and system
DE60008845T2 (en) Combined roll-yaw spacecraft control method for balancing a low orbit
CN108613655B (en) Attitude adjustment method for imaging along inclined strip in agile satellite machine
CN111634445A (en) Low-orbit satellite large-width detection vertical orbit swinging scanning method
CN112130590B (en) Satellite-borne antenna ground pointing determination method based on speed compensation under instantaneous inertial system
CN111045457A (en) Optical axis direction adjusting method based on satellite-borne remote sensing instrument
CN115038095A (en) Multi-beam coverage planning method for low-earth orbit satellite
CN106289156A (en) A kind of satellite is with the method obtaining photography point sun altitude during any attitude imaging
CN109029367A (en) A kind of staring imaging method based on expansion target point
CN113093246A (en) Ground multi-target point imaging rapid judgment and task parameter calculation method
CN111121765B (en) Method for skillfully observing earth and monitoring GEO target by using common remote sensing satellite platform
CN115574840A (en) Moon calibration method suitable for single-track control
Hwangbo et al. Integration of orbital and ground image networks for the automation of rover localization

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20200908

WD01 Invention patent application deemed withdrawn after publication