阅读说明：本技术 一种空间目标姿态可探测性度量方法 (Space target attitude detectability measurement method ) 是由 张海明 逯力红 侯晴宇 高慧 于 2018-06-20 设计创作，主要内容包括：本发明公开了一种空间目标姿态可探测性度量方法。通过对在轨空间目标的光度信号进行仿真,并在仿真结果基础上结合理论分析,提出了一种基于光度信号的姿态可探测性度量,即通过对光度信号的离散程度及同一光度信号下对应的姿态变化角的离散程度进行分析计算,进而说明空间目标的姿态可探测性。本发明解决了没有具体的评判标准来说明用仿真所得的光度信号对姿态进行研究的难易程度的问题,并利用该度量对影响姿态可探测性的因素进行了分析,得到了针对不同情况下的空间目标姿态可探测性。(The invention discloses a spatial target attitude detectability measurement method. By simulating the photometric signal of the on-orbit space target and combining theoretical analysis on the basis of the simulation result, the attitude detectability measurement based on the photometric signal is provided, namely, the attitude detectability of the space target is further explained by analyzing and calculating the discrete degree of the photometric signal and the discrete degree of the corresponding attitude change angle under the same photometric signal. The invention solves the problem that no specific judgment standard is used for explaining the difficulty degree of researching the gesture by using photometric signals obtained by simulation, and the spatial target gesture detectability under different conditions is obtained by analyzing factors influencing the gesture detectability by using the measurement.)

1. A method of spatial target detectability measurement, characterized by: the method comprises the following steps:

(1) ensuring that the photometric signal is detectable in response to the spatial target reaching a requirement to be detectable;

(2) after the step (1) is determined, analyzing the detectability of the spatial target postures of different photometric signals;

(3) based on step (2), a metric is established that can be used to describe the detectability of the attitude of the spatial object to measure the ease of attitude detection by photometric signals.

2. The method of claim 1, wherein: after acquiring the information of the space target such as structure parameters, track parameters, material parameters, attitude matrix and the like, a simulation platform can be established to simulate the photometric signals and images of the on-orbit space target.

3. The method of claim 1, wherein: and (1) the luminosity signal is a luminosity value of the target reflected to the entrance pupil of the detector.

4. The method of claim 1, wherein: the luminosity signal of the target in the orbit space in the step (1) is influenced by various factors such as the relative position relationship between an observation satellite and a target satellite, the relative position relationship between the sun and the target satellite, the attitude of the target satellite and the like.

5. The method of claim 1, further comprising: the step (2) is specifically as follows:

1) selecting a partial orbit which can be irradiated by the sun when the target satellite runs in the whole orbit, changing the relative distance between the observation satellite and the target satellite, and simulating photometric signals of the target satellite received by the observation satellites with different distances;

2) calculating according to the obtained luminosity signal to obtain SNR values at different time, wherein the signal is considered to be detectable when the SNR is more than or equal to 6;

3) in the case where photometric signals obtained by determining the selected conditions are detectable, orbit factors, material factors, a satellite model are determined, and different attitudes of a satellite operating at a point in the orbit are analyzed, that is, only the attitude changes without changing other factors, at which time, attitude detectability is analyzed based on the obtained different photometric signals.

4) When the satellite rotates around the x, y and z axes by different angles, it is known from a lot of experiments that the angles and the obtained photometric signals are not in a one-to-one relationship, i.e. different rotation angles may correspond to the same photometric signal value.

6. The method of claim 1, further comprising: the step (3) is specifically as follows:

1) dividing the luminosity signals obtained when the posture changes at equal intervals;

2) selecting data of the luminosity signals in the same interval, and dividing posture change angles corresponding to the data into an interval;

3) selecting a mean square error capable of describing the data collecting and distributing degree to describe the dispersion condition of the angles in the same luminosity signal interval;

4) establishing a quantity describing a degree of dispersion of the value of the photometric signal corresponding to each interval of the histogram made according to the selected interval width;

5) and comprehensively considering the step 3) and the step 4), obtaining a measure for evaluating the detectability of the spatial target postures.

7. The method of claim 6, further comprising: the equal interval dividing method in the step 1) comprises the following steps:

and selecting interval intervals according to the minimum signal which can be resolved by the selected detector during interval division aiming at the actual situation that the detection sensitivities of different detectors are different.

8. The method of claim 6, further comprising: step 4) the quantity σ describing the degree of angular dispersion corresponding to the same photometric signal value₁The formula of (1) is:

in the formula sigma_m-the mean square error of the corresponding attitude angle within a photometric interval, whose expression is as follows:

in the formula K_m-the number of data in the mth photometric interval;

k-the number of total photometric values;

n is the number of intervals of photometric quantity;

a is the number of data in the interval.

9. The method of claim 6, further comprising: step 5) said quantity σ describing the degree of angular dispersion corresponding to the same photometric signal value₂The formula of (1) is:

in the formula K_m-the number of signals in the mth interval after the interval division;

k-the total number of signal values obtained.

10. The method of claim 6, further comprising: step 6) the formula of the described value σ for evaluating the detectability of the attitude of the spatial target is:

σ＝σ₁·σ₂ (4)。

Technical Field

The invention relates to the field of space target identification, in particular to a space target posture detectability measuring method.

Background

With the development of space exploration technology and the increasing emphasis and dependence of human beings on space utilization, space has become a strategic high point that must be occupied to maintain national security and national interest. The spatial situation perception plays a great role in implementing other spatial actions, and the capability level of the spatial situation perception is closely related to the exertion of the spatial countervailing capability. Therefore, research around spatial target situation awareness is increasingly gaining importance.

At present, scholars at home and abroad have conducted a great deal of research on photometric signals, most of the research work focuses on the radiation and reflection characteristics of a space target, the characteristic modeling of an on-orbit space target, the simulation modeling of space target data and the like, and the research has important reference values for the research. However, in the current study, there is no specific criterion to explain the difficulty of studying the pose with the obtained photometric signal.

Disclosure of Invention

In order to solve the problems, the invention provides an attitude detectability measurement based on photometric signal analysis by carrying out a large amount of simulation on target satellites under different conditions and combining theoretical research, and the technical scheme is as follows:

(1) ensuring that the photometric signal is detectable in response to the spatial target reaching a requirement to be detectable;

(2) after the step (1) is determined, analyzing the detectability of the spatial target postures of different photometric signals;

(3) based on step (2), a metric is established that can be used to describe the detectability of the attitude of the spatial object to measure the ease of attitude detection by photometric signals.

Preferably, the space target in step (1) is a space target in a simulation platform established after analyzing an acquisition method of information such as structure parameters, orbit parameters, material parameters, attitude matrix and the like of the space target.

Preferably, the luminosity signal in step (1) is a luminosity signal value when the target reflects sunlight to the entrance pupil of the detector.

Preferably, the photometric signal in step (1) is affected by various factors, such as a relative position relationship between the observation satellite and the target satellite, a relative position relationship between the sun and the target satellite, and an attitude of the target satellite.

Preferably, the step (2) is specifically:

1) selecting a partial orbit which can be irradiated by the sun when the target satellite runs in the whole orbit, changing the relative position of the observation satellite and the target satellite, and simulating photometric signals of the target satellite received by the observation satellites at different distances;

2) calculating according to the obtained luminosity signal to obtain SNR values at different time, wherein the signal is considered to be detectable when the SNR is more than or equal to 6;

3) in the case of determining that the photometric signal obtained under the currently selected conditions is detectable, the orbit factors, the material factors, the satellite model are determined, and the different attitudes of the satellite operating at a point in the orbit are analyzed, i.e. only the attitude changes without changing other factors, at which time the attitude detectable analysis is performed on the basis of the different photometric signals obtained.

4) When the target satellite rotates around the x, y and z axes by different angles, it can be known from a large number of experiments that the rotation attitude angle and the obtained photometric signal are not in a one-to-one correspondence relationship, i.e. different rotation angles may correspond to the same photometric signal value.

Preferably, the step (3) is specifically:

1) dividing the luminosity signals obtained when the posture changes at equal intervals;

2) selecting data of the luminosity signals in the same interval, and dividing posture change angles corresponding to the data into an interval;

3) selecting a mean square error capable of describing the data dispersion degree to describe the dispersion condition of the angle in the same luminosity signal value interval;

4) establishing a quantity describing the discrete degree of the luminosity signal corresponding to each interval of the histogram divided according to the width of the selected interval;

5) and comprehensively considering the step 3) and the step 4), obtaining a measure for evaluating the detectability of the spatial target postures.

The invention has the following advantages:

the invention provides a posture detectability measurement based on photometric information aiming at photometric signals of an on-orbit space target, namely, the posture detectability of the space target is further explained by analyzing and calculating the photometric signals obtained by simulation and the discrete degree of corresponding posture change angles under the same photometric signals. And the factors influencing the posture detectability are analyzed by utilizing the measurement, so that the posture detectability of the space target under different conditions is obtained. Fills the blank that no related technology exists in China at present.

Drawings

FIG. 1 is a schematic flow chart of a spatial target pose detectability metric provided by the present invention;

FIG. 2 is a photometric signal acquisition process provided by the present invention;

FIG. 3 shows photometric signals and detectability determinations simulated at different distances from a target satellite to an observation satellite;

FIG. 4 is a schematic diagram of interval division of photometric signals obtained by simulation;

FIG. 5 is a diagram of photometric signals obtained by rotation of a target satellite about x, y, and z axes, respectively;

FIG. 6 is a photometric signal obtained from different attitudes of a target satellite operating at a point in orbit, with the orbit, materials, and satellite model, etc. all determined;

Detailed Description

The invention will now be further described with reference to the accompanying drawings and examples. The photometric signal acquisition flow chart of the present invention is shown in fig. 2.

The embodiment of the invention selects the determined structural characteristic parameters, material characteristic parameters, and space targets of the orbit characteristic parameters of the target star and the observation star for simulation analysis.

Fig. 5 shows photometric signals obtained by the target satellite rotating around the x, y and z axes, respectively.

Fig. 6 shows photometric signals obtained from different attitudes of a target satellite operating at a point in the orbit, when the orbit, materials, and satellite model are determined.

A pose detectability metric based on photometric signal analysis, characterized by: the method comprises the following steps:

(1) ensuring that the resulting photometric signal is detectable, in response to a requirement that an object in space be detectable;

(2) after the step (1) is determined, analyzing the detectability of the spatial target postures of different photometric signals;

(3) based on step (2), a metric is established that can be used to describe the detectability of the attitude of the spatial object to measure the ease of attitude detection by photometric signals.

The space target is a space target for simulation in the simulation platform, and the simulation platform simulates the luminosity signals of the space target by utilizing the acquired information of the space target, such as the structure parameters, the track parameters, the material parameters, the attitude matrix and the like.

The luminosity signal is the luminosity signal value of the target reflecting sunlight to the entrance pupil of the detector.

The step (2) is specifically as follows:

1) selecting a partial orbit which can be irradiated by the sun when the target satellite runs in the whole orbit, changing the relative position of the observation satellite and the target satellite, and simulating photometric signals of the target satellite received by the observation satellites at different distances;

2) calculating according to the obtained photometric signal to obtain SNR values at different moments, and considering that the signal is detectable when the SNR is more than or equal to 6;

3) in the case of determining that the photometric signals obtained under the selected conditions are detectable, the orbit factors, the material factors, the satellite model are determined, the different attitudes of the satellite running at one point in the orbit are analyzed, that is, only the attitude of the target changes without changing other factors, and at this time, the attitude detectable analysis is performed according to the obtained different photometric signals.

4) When the target satellite rotates around the x, y and z axes by different angles, it can be known from a large number of experiments that the rotation attitude angle and the obtained photometric signal are not in a one-to-one correspondence relationship, i.e. different rotation angles may correspond to the same photometric signal value.

The step (3) is specifically as follows:

1) dividing the luminosity signals obtained when the posture changes at equal intervals;

2) selecting data of the luminosity signals in the same interval, and dividing posture change angles corresponding to the data into an interval;

3) selecting a mean square error capable of describing the data collecting and distributing degree to describe the dispersion condition of the angle in the same luminosity signal value interval;

4) establishing a quantity describing the angular dispersion degree of the corresponding data of the same luminosity signal value;

5) establishing a quantity describing the degree of dispersion of the value of the photometric signal corresponding to each interval of the histogram divided according to the width of the selected interval; (ii) a

6) And step 4) and step 5) are considered together, so that a measure for evaluating the detectability of the spatial target postures can be obtained.

The method provides a spatial target posture detectability measurement aiming at the current situation that no spatial target posture detectability standard is judged at home at present.