CN103776427A

CN103776427A - Parameter setting and adjusting method applied to stereo mapping camera

Info

Publication number: CN103776427A
Application number: CN201410026118.1A
Authority: CN
Inventors: 何红艳; 齐文雯; 高卫军; 王小燕; 李方琦; 高凌雁; 赵占平; 李岩
Original assignee: Beijing Research Institute of Mechanical and Electrical Technology
Current assignee: Beijing Spaceflight Creative Technology Co Ltd
Priority date: 2014-01-21
Filing date: 2014-01-21
Publication date: 2014-05-07
Anticipated expiration: 2034-01-21
Also published as: CN103776427B

Abstract

The invention discloses a parameter setting and adjustment method applied to a stereoscopic surveying and mapping camera. The invention studies the stereoscopic imaging model of a three-line array surveying and mapping camera, and provides three cameras under different imaging conditions according to different camera installation methods and satellite orbit parameters. The difference in the entrance pupil radiance when imaging the same target, combined with the actual camera responsivity and the difference in on-orbit integration time gives the output response difference of the three cameras, thus realizing the Imaging parameters are adjusted in real time for the other two cameras. The invention provides dynamic matching settings of camera imaging parameters at different latitudes, and improves the radiation quality of stereoscopic images.

Description

A Parameter Setting and Adjusting Method Applied to Stereo Mapping Camera

技术领域technical field

本发明涉及一种应用于立体测绘相机的参数设置和调整方法，属于航天光学遥感器应用技术领域，。The invention relates to a parameter setting and adjustment method applied to a stereo surveying and mapping camera, and belongs to the technical field of aerospace optical remote sensor application.

背景技术Background technique

航天测绘技术是航天对地观测成像技术的重要组成部分，是非常重要的一类对地成像观测卫星，并逐渐从军事作战航天保障体系的重要组成部分发展成为现代战争作战能力的重要组成部分。在民用测绘技术领域，航天测绘技术也是一种现代化高效测绘技术手段。Aerospace surveying and mapping technology is an important part of aerospace earth observation and imaging technology, and it is a very important type of earth imaging observation satellite. It has gradually developed from an important part of military combat space support system to an important part of modern warfare combat capabilities. In the field of civilian surveying and mapping technology, aerospace surveying and mapping technology is also a modern and efficient means of surveying and mapping technology.

测绘相机是测绘卫星上的重要有效载荷，以推扫成像的CCD测量相机，受到国际上普遍的关注，按照CCD相机组合方式不同及摄影测量原理不同可分为三类：单线阵CCD相机，星载双线阵测量相机和三线阵CCD立体测绘相机。Surveying and mapping cameras are important payloads on surveying and mapping satellites. The CCD surveying cameras that use push-broom imaging have attracted widespread attention in the world. According to the different combinations of CCD cameras and the principles of photogrammetry, they can be divided into three categories: single-line array CCD cameras, satellite Equipped with a dual linear array measuring camera and a triple linear array CCD stereoscopic mapping camera.

三线阵测绘相机包括垂直对地成像的正视相机、向前倾斜成像的前视相机以及向后倾斜成像的后视相机。各相机自带完整的光学成像系统，分别独立工作。在卫星平台的轨道运行中，前视相机、正视相机和后视相机相隔一段时间先后对目标区域照准成像，获取该区域的重叠影像。随着测绘技术的发展，对重叠影像的辐射和几何特性提出了越来越高的要求。为了保证三台相机对同一目标成像的辐射特性的一致性，需要适时的调整相机的成像参数，达到高精度的图像匹配能力。The three-line array mapping camera includes a front-view camera that images vertically to the ground, a front-view camera that tilts forward to image, and a rear-view camera that tilts backward to image. Each camera comes with a complete optical imaging system and works independently. During the orbital operation of the satellite platform, the forward-looking camera, the front-looking camera and the rear-looking camera aim at and image the target area at intervals of time to obtain overlapping images of the area. With the development of surveying and mapping technology, higher and higher requirements are placed on the radiometric and geometric properties of overlapping images. In order to ensure the consistency of the radiation characteristics of the three cameras imaging the same target, it is necessary to adjust the imaging parameters of the cameras in a timely manner to achieve high-precision image matching capabilities.

目前太阳高度角的计算只考虑卫星的轨道参数，得到的卫星观测的太阳高度角即是相机的，而测绘卫星上一般有几台相机，且不同相机在卫星上的安装方式不一致，导致不同相机对同一目标成像时的成像时刻和观测角度均不同，这种观测条件的差异会引起大气传输路径的改变，从而影响同一目标到达不同相机前的入瞳辐亮度。At present, the calculation of the sun altitude angle only considers the orbit parameters of the satellite, and the obtained sun altitude angle observed by the satellite is the camera, and there are usually several cameras on the surveying and mapping satellite, and the installation methods of different cameras on the satellite are inconsistent, resulting in different cameras. When imaging the same target, the imaging time and observation angle are different. The difference in observation conditions will cause the change of the atmospheric transmission path, thus affecting the entrance pupil radiance of the same target before reaching different cameras.

发明内容Contents of the invention

本发明的技术解决问题是：克服现有技术的不足，提出了一种应用于立体测绘相机的参数设置和调整方法，根据不同相机的安装方式以及卫星轨道参数给出不同成像条件下三台相机对同一目标成像时的入瞳辐亮度的差异，并结合相机实际响应度以及在轨积分时间的差异给出了三台相机的输出响应差异，从而实现了通过设置一台相机的成像参数实时地调整其他两台相机进而达到测量的一致性。The technical problem of the present invention is: to overcome the deficiencies in the prior art, a parameter setting and adjustment method applied to stereo surveying and mapping cameras is proposed, and three cameras under different imaging conditions are given according to different camera installation methods and satellite orbit parameters The difference in the entrance pupil radiance when imaging the same target, combined with the actual camera responsivity and the difference in on-orbit integration time gives the output response difference of the three cameras. Adjust the other two cameras to achieve measurement consistency.

本发明的技术方案是：Technical scheme of the present invention is:

一种应用于立体测绘相机的参数设置和调整方法，包括步骤如下：A parameter setting and adjustment method applied to a stereoscopic mapping camera, comprising the following steps:

1）确定太阳高度角、太阳方位角、相机观测方位角和相机观测高度角；所述太阳高度角为太阳与地面目标的连线与过地面目标的法平面之间的夹角；所述太阳方位角为太阳与地面目标的连线在地球表面的投影线与地球表面上过地面目标正北方位线的夹角；所述相机观测方位角表示相机与地面目标的连线在地面的投影与正北方向的夹角；所述相机观测高度角表示相机与卫星垂直对地轴的夹角；1) Determine the sun altitude angle, sun azimuth angle, camera observation azimuth angle and camera observation altitude angle; the sun altitude angle is the angle between the line connecting the sun and the ground target and the normal plane passing through the ground target; the sun The azimuth angle is the angle between the projection line of the line connecting the sun and the ground target on the earth's surface and the azimuth line passing the due north of the ground target on the earth's surface; the camera observation azimuth represents the projection and The included angle of the true north direction; the camera observation elevation angle represents the included angle between the camera and the satellite vertical to the earth axis;

2）根据当前立体测绘相机成像时刻的太阳赤纬角ω和太阳时角t，计算出纬度范围[-90°,90°]内每隔10°的太阳高度角h_S；2) According to the solar declination angle ω and solar hour angle t at the imaging moment of the current stereoscopic mapping camera, calculate the solar altitude angle h _S every 10° within the latitude range [-90°, 90°];

3）根据步骤（2）中计算出的太阳高度角h_S以及太阳赤纬角ω和太阳时角t计算不同纬度下的太阳方位角ψ_s；3) Calculate the solar azimuth ψ _s at different latitudes according to the solar altitude angle h _S calculated in step (2), the solar declination angle ω, and the solar hour angle t;

4）根据测绘卫星上三台相机（前视相机、后视相机和正视相机）的视轴矢量以及卫星轨道的倾角计算出纬度范围[-90°,90°]内的每隔10°下不同相机的观测高度角h_V和观测方位角ψ_v；4) According to the boresight vectors of the three cameras (forward-looking camera, rear-looking camera and front-looking camera) on the surveying and mapping satellite and the inclination angle of the satellite orbit, calculate the difference of every 10° in the latitude range [-90°, 90°] Observation height angle h _V and observation azimuth angle ψ _v of the camera;

5）统计卫星图像，通过图像反演得到春分、夏至、秋分和冬至四个典型节气下地面目标的真实反射率；5) Statistical satellite images, through image inversion to obtain the true reflectance of ground targets under the four typical solar terms of vernal equinox, summer solstice, autumnal equinox and winter solstice;

6）根据太阳高度角h_S、太阳方位角ψ_s、相机观测高度角h_V、相机观测方位角ψ_v以及步骤5）计算得到的地面目标的真实反射率ρ，计算出不同目标反射率下每台相机的入瞳辐亮度L，从而得到不同成像时刻三台相机之间的辐亮度差异；6) According to the sun altitude angle h _S , sun azimuth angle ψ _s , camera observation altitude angle h _V , camera observation azimuth angle ψ _v and the real reflectivity ρ of the ground target calculated in step 5), calculate the The entrance pupil radiance L of each camera, so as to obtain the radiance difference between the three cameras at different imaging moments;

7）确定三台相机在相同辐亮度和相同相机参数下的响应度差异，根据积分球辐射定标数据，提取出三台相机在相同成像参数下的定标数据，得出相同辐亮度下不同相机的响应度差异；7) Determine the difference in responsivity of the three cameras under the same radiance and the same camera parameters, and extract the calibration data of the three cameras under the same imaging parameters according to the radiation calibration data of the integrating sphere, and obtain the difference under the same radiance Differences in camera responsivity;

8）计算出以正视相机为基准，前后视相机与正视相机在任一成像时刻的响应输出的相对关系；所述的响应输出的相对关系确定方法如下：8) Calculate the relative relationship between the response output of the front-facing camera and the front-facing camera at any imaging moment with the front-facing camera as the reference; the relative relationship determination method of the response output is as follows:

a）根据步骤6）得到前后视相机相对于正视相机的辐亮度差异；a) Obtain the difference in radiance between the front and rear camera relative to the front camera according to step 6;

b）根据步骤7）得到前后视相机相对于正视相机的响应度差异；b) According to step 7), the difference in responsivity between the front and rear camera relative to the front camera is obtained;

c）根据GPS实时计算的积分时间得到前后视相机相对于正视相机的积分时间差异；c) According to the integration time calculated in real time by GPS, the integration time difference of the front and rear camera relative to the front camera is obtained;

d）将步骤a）、b）和c）得到的辐亮度差异、响应度差异和积分时间差异进行累积相乘得到最终的响应输出的相对关系；d) Accumulate and multiply the radiance difference, responsivity difference and integration time difference obtained in steps a), b) and c) to obtain the relative relationship of the final response output;

9）根据积分球辐射定标数据得到的绝对定标系数确定不同成像时刻正视相机的成像参数，然后根据步骤8）的相对关系对前后视相机的成像参数进行调整，原则也是先调整TDI（Time Delay Integration）级数，再调整相机增益。9) According to the absolute calibration coefficient obtained from the integrating sphere radiation calibration data, determine the imaging parameters of the front-facing camera at different imaging moments, and then adjust the imaging parameters of the front and rear-looking cameras according to the relative relationship in step 8). The principle is to adjust the TDI (Time Delay Integration) series, and then adjust the camera gain.

所述步骤2）的太阳高度角h_S的具体计算公式为：The specific calculation formula of the sun altitude angle h _S in the step 2) is:

sin h_s=cosΦcosωcost+sinΦsinωsin h _s =cosΦcosωcost+sinΦsinω

${h h}_{s the s} = = arcsin arcsin {{cos cos Φ Φ cos cos [[23.5 23.5 sin sin ((\frac{t t}{365365}))]] cos cos t t + + sin sin Φ Φ sin sin [[23.5 23.5 sin sin ((\frac{t t}{365365}))]]}};;$

其中t∈[0,131400]，从1日0时开始，终止时刻为第365日24时，每24小时t变化了360°，Φ表示为纬度。Where t∈[0,131400] starts at 0:00 on the 1st day and ends at 24:00 on the 365th day. Every 24 hours t changes by 360°, and Φ is expressed as latitude.

所述步骤3）的太阳方位角ψ_s的具体计算公式为：The specific calculation formula of the solar azimuth ψ _s in the step 3) is:

${ψ ψ}_{s the s} = = \{\begin{matrix} 360360 - - arccos arccos [[\frac{sin sin {h h}_{s the s} sin sin ω ω - - sin sin ((23.5 23.5 sin sin ((\frac{t t}{365365}))))}{cos cos {h h}_{s the s} cos cos ω ω}]] 360360 k k < < t t < < 360360 k k + + 180180 \\ arccos arccos [[\frac{sin sin {h h}_{s the s} sin sin ω ω - - sin sin ((23.5 23.5 sin sin ((\frac{t t}{365365}))))}{cos cos {h h}_{s the s} cos cos ω ω}]] 360360 k k + + 180180 \leq \leq t t < < 360360 k k + + 360360 \end{matrix}$

其中k为0、1、2、…、364。where k is 0, 1, 2, . . . , 364.

所述步骤4）的相机观测高度角h_v和相机观测方位角Ψ_v的具体计算公式为：前视相机与正视相机之间的交会角为φ₁，后视相机与正视相机之间的交会角为φ₂，卫星的侧摆角度为θ（θ>0表示往东侧摆，θ<0表示往西侧摆），轨道倾角为δ,则三台相机的观测高度角h_V分别为：The specific calculation formulas of the camera observation height angle h _v and the camera observation azimuth Ψ _v in step 4) are: the intersection angle between the front-view camera and the front-view camera is φ ₁ , and the intersection angle between the rear-view camera and the front-view camera The angle is φ ₂ , the side roll angle of the satellite is θ (θ>0 means the east side swing, θ<0 means the west side swing), and the orbit inclination angle is δ, then the observation height angles h _V of the three cameras are respectively:

前视相机：arccos(cosφ₁cosθ)Front view camera: arccos(cosφ ₁ cosθ)

正视相机：θOrtho-facing camera: θ

后视相机：arccos(cosφ₂cosθ)Rear view camera: arccos(cosφ ₂ cosθ)

相机的观测方位角ψ_v为：The observation azimuth ψ _v of the camera is:

前视相机： $\{\begin{matrix} 180 - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) + δ & θ > 0 \\ δ - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) & θ < 0 \end{matrix}$ Front view camera: $\{\begin{matrix} 180 - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ &Center Dot; \cos φ_{1})}^{2}}}) + δ & θ > 0 \\ δ - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) & θ < 0 \end{matrix}$

正视相机： $\{\begin{matrix} 180 + δ & θ > 0 \\ δ & θ < 0 \end{matrix}$ Face up to the camera: $\{\begin{matrix} 180 + δ & θ > 0 \\ δ & θ < 0 \end{matrix}$

后视相机： $\{\begin{matrix} 180 + \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ > 0 \\ \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ < 0 \end{matrix}$ Rear view camera: $\{\begin{matrix} 180 + \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ &Center Dot; \cos φ_{2})}^{2}}}) + δ & θ > 0 \\ \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ &Center Dot; \cos φ_{2})}^{2}}}) + δ & θ < 0 \end{matrix}$

其中以正北方向为0°。Where the true north direction is 0°.

所述步骤9）的绝对定标系数确定和成像参数调整方法如下：The method for determining the absolute calibration coefficient and adjusting the imaging parameters in the step 9) is as follows:

a)首先根据积分球辐射定标数据计算出TDI级数为1级、基准增益和默认积分时间下的绝对定标系数k0和b0；a) First, calculate the absolute calibration coefficients k0 and b0 under the TDI series of 1, reference gain and default integration time based on the radiation calibration data of the integrating sphere;

b）根据在轨实时计算的积分时间和默认积分时间的比值q得到当前积分时间下的绝对定标系数k1=q*k0；b) Obtain the absolute calibration coefficient k1=q*k0 under the current integration time according to the ratio q of the integration time calculated in real time on the orbit and the default integration time;

c）根据正视相机的入瞳辐亮度80%饱和输出对应的绝对定标系数k2；c) The absolute calibration coefficient k2 corresponding to the 80% saturation output of the entrance pupil radiance of the front-facing camera;

d）根据k2/k1的大小选择合适的TDI级数N，N必须小于等于k2/k1，再通过调增益

来满足绝对定标系数的要求。d) Select the appropriate TDI series N according to the size of k2/k1, N must be less than or equal to k2/k1, and then adjust the gain

To meet the requirement of absolute calibration coefficient.

本发明与现有技术相比的优点在于：The advantage of the present invention compared with prior art is:

（1）本发明给出了三线阵测绘相机的准确的立体成像模型，在计算入瞳辐亮度的时候考虑了太阳高度角和方位角、相机高度角和方位角的综合影响。(1) The present invention provides an accurate three-dimensional imaging model of the three-line array surveying and mapping camera, and considers the comprehensive influence of the sun elevation angle and azimuth angle, and the camera elevation angle and azimuth angle when calculating the entrance pupil radiance.

（2）本发明提供了三台相机在不同成像条件下的能量差异及相应的参数调整方案，保证了不同相机输出影像的辐射特性的一致性。(2) The present invention provides the energy difference of the three cameras under different imaging conditions and the corresponding parameter adjustment scheme, which ensures the consistency of the radiation characteristics of the images output by different cameras.

（3）本发明首次提出三线阵立体测绘相机的在轨成像参数设置方法，可直接应用于立体测绘相机的在轨使用，以确保成像质量，也可用于后续机动成像的相机。(3) The present invention proposes for the first time an on-orbit imaging parameter setting method for a three-line array stereoscopic mapping camera, which can be directly applied to the on-orbit use of a stereoscopic mapping camera to ensure imaging quality, and can also be used for subsequent mobile imaging cameras.

（4）本发明采用的TDICCD相机的成像参数在轨优化方法，软件实现方便，易于采用Mat lab或C实现。(4) The on-orbit optimization method of the imaging parameters of the TDICCD camera adopted in the present invention is easy to realize by software, and is easy to realize by using Matlab or C.

附图说明：Description of drawings:

图1为本发明立体测绘相机在轨成像参数调整的流程图；Fig. 1 is a flow chart of the adjustment of the on-orbit imaging parameters of the stereoscopic mapping camera of the present invention;

图2为本发明高度角和方位角定义的示意图；Fig. 2 is the schematic diagram of definition of elevation angle and azimuth angle of the present invention;

图3为本发明立体测绘相机观测角度的示意图。Fig. 3 is a schematic diagram of the observation angle of the stereoscopic mapping camera of the present invention.

具体实施方式Detailed ways

下面结合附图进一步说明本发明的结构组成和工作原理。The structural composition and working principle of the present invention will be further described below in conjunction with the accompanying drawings.

如图1所示，本发明一种应用于立体测绘相机的参数设置和调整方法的方法步骤如下：As shown in Figure 1, the method steps of a parameter setting and adjustment method applied to a stereo surveying and mapping camera in the present invention are as follows:

如图2、3所示为前视相机对地面目标P成像时太阳光照射的方向示意图，h_S表示太阳高度角，是太阳（视为一质点）与地球表面任意一点P的连线与过P点的法平面之间的夹角；ψ_s表示太阳方位角，是指太阳与地球表面P点的连线在过P点的地球表面的投影线与地表面上过P点正北方位线的夹角（计算方位角时统一以正北方向为0°，从北往西逆时针走一圈刚好从0°到360°）。太阳高度角和方位角是表征太阳位置的参数，确定了阳光对于地球表面任意一点的来向；ψ_v1是前视相机的观测方位角，表示前视相机与目标点的连线在地面的投影与正北方向的夹角，h_v1表示前视相机与对地光轴的夹角即相机的观测高度角。Figures 2 and 3 are schematic diagrams of the direction of sunlight irradiation when the forward-looking camera images the ground target P. h _S represents the sun's altitude angle, which is the connection and passage between the sun (as a particle) and any point P on the earth's surface. The included angle between the normal planes of point P; ψ _s represents the azimuth of the sun, which refers to the projection line of the line connecting the sun and point P on the surface of the earth passing through point P on the earth's surface and the azimuth line passing through point P on the earth's surface (When calculating the azimuth, the direction of true north is uniformly taken as 0°, and walking counterclockwise from north to west is exactly from 0° to 360°). The sun's altitude and azimuth are parameters that characterize the sun's position, and determine the direction of sunlight to any point on the earth's surface; _ψv1 is the observation azimuth of the forward-looking camera, which represents the projection of the line connecting the forward-looking camera and the target point on the ground The included angle with the true north direction, h _v1 indicates the included angle between the forward-looking camera and the optical axis of the ground, that is, the observation height angle of the camera.

太阳高度角h_S的具体计算公式为：The specific calculation formula of the sun altitude angle h _S is:

sin h_s=cosΦcosωcost+sinΦsinωsin h _s =cosΦcosωcost+sinΦsinω

太阳方位角ψ_s的具体计算公式为：The specific calculation formula of the solar azimuth ψ _s is:

其中k为0、1、2、…、364。where k is 0, 1, 2, . . . , 364.

相机观测高度角h_v和相机观测方位角Ψ_v的具体计算公式为：前视相机与正视相机之间的交会角为φ₁，后视相机与正视相机之间的交会角为φ₂，卫星的侧摆角度为θ（θ>0表示往东侧摆，θ<0表示往西侧摆），轨道倾角为δ,则三台相机的观测高度角h_V分别为：The specific calculation formulas of the camera observation height angle h _v and the camera observation azimuth Ψ _v are: the intersection angle between the forward-looking camera and the front-looking camera is φ ₁ , the intersection angle between the rear-looking camera and the front-looking camera is φ ₂ , and the satellite The side swing angle of θ is θ (θ>0 means the east side swing, θ<0 means the west side swing), and the orbital inclination angle is δ, then the observation height angles h _V of the three cameras are respectively:

前视相机：arccos(cosφ₁cosθ)Front view camera: arccos(cosφ ₁ cosθ)

正视相机：θOrtho-facing camera: θ

后视相机：arccos(cosφ₂cosθ)Rear view camera: arccos(cosφ ₂ cosθ)

前视相机： $\{\begin{matrix} 180 - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) + δ & θ > 0 \\ δ - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) & θ < 0 \end{matrix}$ Front view camera: $\{\begin{matrix} 180 - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) + δ & θ > 0 \\ δ - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ &Center Dot; \cos φ_{1})}^{2}}}) & θ < 0 \end{matrix}$

后视相机： $\{\begin{matrix} 180 + \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ > 0 \\ \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ < 0 \end{matrix}$ Rear view camera: $\{\begin{matrix} 180 + \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ > 0 \\ \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ < 0 \end{matrix}$

其中以正北方向为0°。Where the true north direction is 0°.

9）根据积分球辐射定标数据得到的绝对定标系数确定不同成像时刻正视相机的成像参数，然后根据步骤8）的相对关系对前后视相机的成像参数进行调整，原则也是先调整TDI（Time Delay Integration）级数，再调整相机增益；9) According to the absolute calibration coefficient obtained from the integrating sphere radiation calibration data, determine the imaging parameters of the front-facing camera at different imaging moments, and then adjust the imaging parameters of the front and rear-looking cameras according to the relative relationship in step 8). The principle is to adjust the TDI (Time Delay Integration) series, and then adjust the camera gain;

绝对定标系数确定和成像参数调整方法如下：The methods for determining the absolute calibration coefficient and adjusting the imaging parameters are as follows:

a)首先根据积分球辐射定标数据计算出TDI级数为1级、基准增益（即1对模拟信号1:1量化）和默认积分时间下的绝对定标系数k0和b0（测绘相机的b0一般比较小，在下面的计算中可以不考虑）；a) First, calculate the absolute calibration coefficients k0 and b0 (b0 of the surveying and mapping camera) based on the radiation calibration data of the integrating sphere under the TDI series of 1, the reference gain (that is, 1 pair of analog signals quantized at 1:1) and the default integration time Generally relatively small, it can be ignored in the following calculations);

d）根据k2/k1的大小选择合适的TDI级数N，N必须小于等于k2/k1（且满足尽量接近k2/k1），再通过调增益

来满足绝对定标系数的要求（在增益

不能满足的情况下，再调节增益

绝对定标系统根据需求而定）。d) Select the appropriate TDI series N according to the size of k2/k1, N must be less than or equal to k2/k1 (and satisfy as close as possible to k2/k1), and then adjust the gain

to meet the absolute scaling factor requirements (at gain

If not satisfied, then adjust the gain

Absolute calibration system depends on demand).

本发明说明书中未作详细描述的内容属于本领域技术人员的公知技术。The contents not described in detail in the description of the present invention belong to the well-known technology of those skilled in the art.

Claims

1. be applied to parameter setting and the method for adjustment of tridimensional mapping camera, it is characterized in that step is as follows:

1) determine sun altitude, solar azimuth, camera observed azimuth and camera observed altitude angle; Described sun altitude is the angle between the line of the sun and terrain object and the normal plane of crossing terrain object; Described solar azimuth is the angle of crossing the positive northern bit line of terrain object on the projection line at the earth's surface of line of the sun and terrain object and earth surface; Described camera observed azimuth represents that the line of camera and terrain object is at the projection on ground and the angle of direct north; Described camera observed altitude angle represents camera angle to the earth's axis vertical with satellite;

2), according to the declination angle ω in current tridimensional mapping camera imaging moment and solar hour angle t, calculate the sun altitude h every 10 ° in latitude scope [90 °, 90 °] _s;

3) according to the sun altitude h calculating in step (2) _sand declination angle ω and solar hour angle t calculate the solar azimuth ψ under different latitude _s;

4) according to the inclinometer of the optical axis vector of three cameras on cartographic satellite and satellite orbit calculate in latitude scope [90 °, 90 °] every the observed altitude angle of 10 ° of lower different cameral h _vwith observed azimuth ψ _v;

5) statistics satellite image, obtains the real reflectance of terrain object under the Spring Equinox, the Summer Solstice, the Autumnal Equinox and Winter Solstice four typical solar term by image inverting;

6) according to sun altitude h _s, solar azimuth ψ _s, camera observed altitude angle h _v, camera observed azimuth ψ _vand the real reflectance ρ of the terrain object that calculates of step 5), calculate the entrance pupil spoke brightness L of every camera under different target reflectivity, thereby obtain the spoke luminance difference between three cameras of different imaging moment;

7) determine the responsiveness difference of three cameras under identical spoke brightness and identical camera parameter, according to integrating sphere radiation calibration data, extract the calibration data of three cameras under identical imaging parameters, draw the responsiveness difference of different cameral under identical spoke brightness;

8) calculating to face camera is benchmark, front-and rear-view camera with face the relativeness of camera in the response output in arbitrary imaging moment; The relativeness of described response output determines that method is as follows:

A) obtain front-and rear-view camera with respect to the spoke luminance difference of facing camera according to step 6);

B) obtain front-and rear-view camera with respect to the responsiveness difference of facing camera according to step 7);

Obtain front-and rear-view camera with respect to difference integral time of facing camera the integral time of c) calculating in real time according to GPS;

D) the spoke luminance difference that by step a), b) and c) obtains, responsiveness difference and integral time difference accumulate to multiply each other and obtain the relativeness of final response output;

9) the absolute calibration coefficient obtaining according to integrating sphere radiation calibration data and then definite different imaging moment are faced the imaging parameters of camera, then according to the relativeness of step 8), the imaging parameters of front-and rear-view camera is adjusted, principle is also first to adjust TDI progression, then adjusts camera gain.

2. a kind of parameter setting and method of adjustment that is applied to tridimensional mapping camera according to claim 1, is characterized in that: described step 2) sun altitude h _sspecific formula for calculation be:

sin?h _s=cosΦcosωcost+sinΦsinω

h_{s} = \arcsin {\cos Φ \cos [23.5 \sin (\frac{t}{365})] \cos t + \sin Φ \sin [23.5 \sin (\frac{t}{365})]};

Wherein t ∈ [0,131400], since 0 o'clock on the 1st, stopping the moment was 24 o'clock on the 365th, and within every 24 hours, t has changed 360 °, and Φ is expressed as latitude.

3. a kind of parameter setting and method of adjustment that is applied to tridimensional mapping camera according to claim 1, is characterized in that: the solar azimuth ψ of described step 3) _sspecific formula for calculation be:

ψ_{s} = \{\begin{matrix} 360 - \arccos [\frac{\sin h_{s} \sin ω - \sin (23.5 \sin (\frac{t}{365}))}{\cos h_{s} \cos ω}] 360 k < t < 360 k + 180 \\ \arccos [\frac{\sin h_{s} \sin ω - \sin (23.5 \sin (\frac{t}{365}))}{\cos h_{s} \cos ω}] 360 k + 180 \leq t < 360 k + 360 \end{matrix}

Wherein k be 0,1,2 ..., 364.

4. a kind of parameter setting and method of adjustment that is applied to tridimensional mapping camera according to claim 1, is characterized in that: the camera observed altitude angle h of described step 4) _vwith camera observed azimuth ψ _vspecific formula for calculation be: forward sight camera and the intersection angle of facing between camera are φ ₁, rear view camera and the intersection angle of facing between camera are φ ₂, the side-sway angle of satellite is θ, orbit inclination is δ, the observed altitude angle h of three cameras _vbe respectively:

Forward sight camera: arccos (cos φ ₁cos θ)

Face camera: θ

Rear view camera: arccos (cos φ ₂cos θ)

The observed azimuth ψ of camera _vfor:

Forward sight camera:

\{\begin{matrix} 180 - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) + δ & θ > 0 \\ δ - \arccos (\frac{\sin θ \cos φ_{1}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{1})}^{2}}}) & θ < 0 \end{matrix}

Face camera:

\{\begin{matrix} 180 + δ & θ > 0 \\ δ & θ < 0 \end{matrix}

Rear view camera:

\{\begin{matrix} 180 + \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ > 0 \\ \arccos (\frac{\sin θ \cos φ_{2}}{\sqrt{1 - {(\cos θ \cdot \cos φ_{2})}^{2}}}) + δ & θ < 0 \end{matrix}

Wherein, take direct north as 0 °, θ >0 represents that θ <0 represents side-sway westerly toward east side pendulum.

5. a kind of parameter setting and method of adjustment that is applied to tridimensional mapping camera according to claim 1, is characterized in that: absolute calibration parameter identification and the imaging parameters method of adjustment of described step 9) are as follows:

A) first calculate benchmark gain, give tacit consent to absolute calibration coefficient k 0 and b0 under integral time and when TDI progression is 1 grade according to integrating sphere radiation calibration data, described benchmark gain is that 1 couple of simulating signal 1:1 quantizes;

B) according to obtaining the absolute calibration coefficient k 1=q*k0 under current integral time with the ratio q that gives tacit consent to integral time the integral time of calculating in real time in-orbit;

C) according to absolute calibration coefficient k 2 corresponding to entrance pupil spoke brightness 80% saturated output of facing camera;

D) select suitable TDI progression N according to the size of k2/k1, N must be less than or equal to k2/k1, then gains by tune

meet the requirement of absolute calibration coefficient.