A Sequential Waiting Tracking Method

Abstract

The present invention belongs to the technical field of space target observation, and specifically relates to a sequence waiting tracking method. The present invention divides the observation area into an observation sequence. In each observation waiting sequence, the device is stationary. After the observation of the current interval is completed, the device moves the direction to the position of the next observation sequence. In each observation waiting sequence, even if long exposure imaging is used, the stars can still basically form a circular star image, and the star image of the space target has a certain tail. Taking the geometric center of the tailing star image as the target centroid can ensure the calibrated detection of the target, and finally obtain high-precision astronomical positioning data. At the same time, by optimizing the interval strategy of the waiting sequence, the minimum number of adjustments and the longest arc segment covered by each waiting sequence are taken into account, which not only reduces the invalid adjustment of the equipment, but also minimizes the missed sky area caused by the adjustment of the equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of space target observation, and in particular relates to a sequence waiting tracking method. Background Art

[0002] Space targets refer to all artificial celestial bodies orbiting the Earth, including active satellites in orbit, failed satellites, rocket bodies, operational debris, fragments generated by explosion and collision, etc. With the increasing number of human space activities, the number of space targets is increasing rapidly. For the safety of space activities, it is necessary to conduct daily observation and catalog management of space targets.

[0003] When an astronomical telescope observes space targets, the commonly used observation modes are static, automatic or semi-automatic target tracking observation. Automatic target tracking means that the telescope extracts the target position information in real time during the observation process, and adjusts the servo system parameters in real time based on this information, so that the observed target is always in the center of the field of view. Semi-automatic target tracking means that the telescope follows the guidance data for tracking, and does not require a closed loop of target information. In the conventional automatic tracking or semi-automatic tracking mode, the telescope is always in a state of following the target movement.

[0004] For dim space targets flying at a faster speed, in order to improve the detection efficiency of the target, the exposure time of the detector is usually increased. When the target flies at a faster speed, the background stars will show an obvious tailing phenomenon. The decrease in the positioning accuracy of the star target will lead to a decrease in the astronomical positioning accuracy of the space target or a failure of astronomical positioning. Summary of the invention

[0005] The purpose of the present invention is to propose an observation method of sequence waiting tracking suitable for wide-field astronomical telescopes in response to the above problems, and divide the observation area into an observation sequence. In each observation waiting sequence, the device is stationary. After the observation of the current interval is completed, the device moves the direction to the position of the next observation sequence. In each observation waiting sequence, even if long exposure imaging is used, the stars can still basically form a circular star image, and the star image of the space target has a certain tail. Taking the geometric center of the tailing star image as the target centroid can ensure the calibrated detection of the target, and finally obtain high-precision astronomical positioning data. At the same time, by optimizing the interval strategy of the waiting sequence, the minimum number of adjustments and the longest arc segment covered by each waiting sequence are taken into account, which not only reduces the invalid adjustment of the equipment, but also minimizes the missed sky area caused by the adjustment of the equipment.

[0006] The technical solution of the present invention is:

[0007] A sequence waiting tracking method is used for observing a target with a wide field of view astronomical telescope, comprising the following steps:

[0008] S1. Preliminary estimate of the starting position coordinates (A1, E1) and the ending position coordinates (A1, E1) of the target observation arc relative to the observation center based on the target orbit root number and the equipment site coordinates. end 、E end ), define the telescope field of view as 2K, generate a waiting sequence of the observation area based on the starting position and the ending position combined with the telescope field of view, and let the interval △K between the centers of the fields of view of adjacent sequences be:

[0009]

[0010] Between adjacent waiting sequences, the adjustment steps △A and △E of the azimuth and pitch directions along the target flight direction are:

[0011] sin(△A)=sin(△K)·sinψ / cosE N

[0012] sin(△E)=sin(△K)·sinE N +sin(△A)·cosE N ·cosψ

[0013] Among them, ψ is the angle between the target flight trajectory and the horizontal plane;

[0014] The waiting time during each sequence is:

[0015]

[0016] Where v is the angular velocity of the target relative to the observation site; adjust the telescope pointing to the initial observation position (A1-K, E1-K);

[0017] S2. Use the sequence waiting tracking method to observe the target, specifically:

[0018] Based on the parameters obtained in step S1, starting from the initial observation position, the telescope stays at each observation position for △t time for static observation, and then adjusts the telescope to the next sequence position as the new observation position until it reaches the end position A end 、E end ), the observation of the target ends.

[0019] The beneficial effects of the present invention are: reducing the ineffective adjustment of the equipment and minimizing the missed sky area caused by the adjustment of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the sequence spacing strategy of the present invention.

[0021] Figure 2 This is a diagram of the spatial relationship of the telescope's visual axis pointing. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0023] The present invention proposes a sequence waiting tracking method and a sequence interval adjustment strategy for fast-flying dim targets. The telescope does not need to adjust its pointing direction to track the flying target all the time, but adopts a sequence tracking working mode. During the sequence waiting period, the telescope is stationary. After the sequence is executed, the telescope will adjust its pointing direction to the next tracking sequence and continue observation.

[0024] The present invention adopts a sequence waiting tracking method. The telescope determines the starting position of a target observation arc segment according to the number of target orbit elements and the telescope site, and then generates a waiting sequence of the observation area in combination with the field of view of the telescope, and adjusts the telescope pointing to the first sequence position; after entering the sequence waiting period, the telescope is stationary and adopts a longer exposure time, while taking into account the imaging of background stars and faint targets; after the sequence waiting period ends, the telescope adjusts its pointing to the next waiting sequence, enters the next sequence waiting period to continue observation, until all the established observation sequences are executed.

[0025] like Figure 1 The sequence interval adjustment strategy of the present invention is shown in FIG. The interval of the tracking sequence is related to the target flight angular velocity, the field of view of the telescope, etc. If the sequence interval is set too small, the number of equipment adjustments will increase, and the effective information of the target will not be obtained during the adjustment process, which will reduce the detection efficiency of the telescope; if the sequence interval is too large, some sky areas will be missed, so a reasonable sequence interval needs to be set.

[0026] like Figure 2 As shown in the figure, it is a spatial relationship diagram of the telescope's visual axis pointing, where ON and ON+1 are the directions of the center of the field of view of the adjacent sequence, ψ is the angle between the target flight track and the horizontal plane, ΔK is the angle between the center of the field of view of the adjacent sequence, and E N 、E N+1 is the elevation value of the center of the field of view of the adjacent sequence, and ΔA is the projection value of the angle between the center of the field of view of the adjacent sequence in the azimuth direction.

[0027] The present invention adopts the overlap of inscribed circle fields of view, and the interval ΔK between the centers of adjacent sequence fields of view is:

[0028]

[0029] Corresponding to adjacent waiting sequences, the adjustment steps ΔA and ΔE of the azimuth and pitch directions along the target flight direction are:

[0030] sin(ΔA)=sin(ΔK)·sinψ / cosE N

[0031] sin(ΔE)=sin(ΔK)·sinE N +sin(ΔA)·cosE N ·cosψ

[0032] Where ψ is the angle between the target flight trajectory and the horizontal plane.

[0033] The waiting time during each sequence is:

[0034]

[0035] V is the angular velocity of the flying target relative to the observation station.

[0036] The implementation method of the present invention is:

[0037] The telescope preliminarily estimates the starting position (A1, E1) and ending position (A1, E1) of the target observation arc relative to the observation center based on the target orbital elements and the equipment site coordinates. end 、E end ). The telescope field of view is 2K, adjust the telescope pointing to (A1-K, E1-K)

[0038] During the sequence waiting period, the telescope is stationary to acquire the image of the space target. The star target is a relatively round star image that meets the star recognition conditions. The star image of the space target has a slight tail. The geometric center of the space target's tail image is used as the target center of mass, and then the position of the target is given according to the relative position of the space target and the background stars. Both the six-constant model and the 12-constant model are acceptable.

[0039] The time the device stays in each sequence waiting period is After the dwell period, the telescope is adjusted to point to the next sequence waiting position, where the center of the field of view is (A N+1 、E N+1 ), after the adjustment is completed, the device enters the sequence waiting period.

[0040] When the center of the telescope's field of view reaches the end position (A end 、E end ), the observation of the target ends.

Claims

1. A sequential waiting tracking method for observing a target with a wide-field astronomical telescope, characterized in that: The following steps are involved: S1. Preliminary estimate of the starting position coordinates (A1, E1) and the ending position coordinates (A1, E1) of the target observation arc relative to the observation center based on the target orbit root number and the equipment site coordinates. end 、E end ), define the telescope field of view as 2K, generate a waiting sequence of the observation area based on the starting position and the ending position combined with the telescope field of view, and let the interval △K between the centers of the fields of view of adjacent sequences be: Between adjacent waiting sequences, the adjustment steps △A and △E of the azimuth and pitch directions along the target flight direction are: sin(△A)=sin(△K)·sinψ / cosE N sin(△E)=sin(△K)·sinE N +sin(△A)·cosE N ·basket Among them, E N is the pitch value pointed by the center of the field of view in the previous sequence in the adjacent sequence, and ψ is the angle between the target flight trajectory and the horizontal plane; The waiting time during each sequence is: Where v is the angular velocity of the target relative to the observation site; adjust the telescope pointing to the initial observation position (A1-K, E1-K); S2. Use the sequence waiting tracking method to track and observe the target, specifically: Based on the parameters obtained in step S1, starting from the initial observation position, the telescope stays at each observation position for △t time for static observation, and then adjusts the telescope to the next sequence position as the new observation position for static observation again until it reaches the end position (A end 、E end ), the tracking and observation of the target ends.

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