Fire point sensor longitude and latitude measuring method
阅读说明：本技术 一种火点敏感器经纬度测定方法 (Fire point sensor longitude and latitude measuring method ) 是由 刘洁 张涛 陈超 周剑敏 乌日娜 邓楼楼 程莉 刘彤 杨晓龙 王子寒 于 2021-08-30 设计创作，主要内容包括：本发明提供了一种火点敏感器经纬度测定方法,包括确定火点检测敏感器在卫星的安装矩阵和安装位置；获得敏感器输出火点在敏感器基准镜坐标系中的方位矢量和火点时刻；卫星计算机存储有卫星姿态数据,通过查表得到火点对应时间的卫星姿态信息；根据火点时刻计算该时刻的卫星轨道位置、卫星从J2000惯性坐标系到卫星轨道坐标系的转换矩阵、岁差章动矩阵以及格林尼治恒星时角；根据火点时刻的卫星轨道信息、卫星姿态信息、敏感器安装信息、敏感器输出的火点方位矢量信息,获得地心指向地面火点的位置矢量信息；根据地心指向地面火点的位置矢量,获得火点的地理经纬度信息。本发明的火点的经纬度测定方法,提高了敏感器的实用性和智能化、自主化水平。(The invention provides a fire point sensor longitude and latitude measuring method, which comprises the steps of determining an installation matrix and an installation position of a fire point detection sensor in a satellite; obtaining an orientation vector and a fire point moment of a sensor output fire point in a sensor reference mirror coordinate system; the satellite computer stores satellite attitude data, and satellite attitude information of corresponding time to a fire point is obtained by looking up a table; calculating the satellite orbit position at the moment, a conversion matrix of the satellite from a J2000 inertial coordinate system to a satellite orbit coordinate system, a nutation matrix of the time difference and a Greenwich mean star time angle according to the moment of the fire point; acquiring position vector information of the geocenter pointing to the ground fire according to the satellite orbit information, the satellite attitude information, the sensor installation information and the fire azimuth vector information output by the sensor at the fire moment; and acquiring the geographical longitude and latitude information of the fire point according to the position vector of the earth center pointing to the ground fire point. The method for measuring the longitude and latitude of the fire point improves the practicability, intelligence and autonomy level of the sensor.)
1. A fire point longitude and latitude measuring method of a fire point sensor is characterized by comprising the following steps:
(1) determining an installation matrix and an installation position of a fire detection sensor in a satellite;
(2) obtaining an orientation vector u of an output fire point of the sensor in a sensor reference mirror coordinate systempAnd the ignition time t _ fire;
(3) the satellite computer stores satellite attitude data and obtains satellite attitude information at the moment of fire by looking up a table;
(4) determining the satellite orbit position, a conversion matrix of the satellite from a J2000 inertial coordinate system to a satellite orbit coordinate system, a nutation matrix of the time and a Greenwich mean star time angle at the moment according to the fire point moment;
(5) acquiring position vector information of the geocenter pointing to the ground fire according to the satellite orbit information, the satellite attitude information, the sensor installation information and the fire azimuth vector information output by the sensor at the fire moment;
(6) and acquiring the geographical longitude and latitude information of the fire point according to the position vector of the earth center pointing to the ground fire point.
2. The fire point longitude and latitude measuring method of the fire point sensor of claim 1, wherein in the step (1), the installation matrix is a coordinate system Ox of the reference mirror of the sensorayazaDirection cosine matrix to satellite body coordinate systemThe mounting position is a coordinate vector of the origin of the sensor reference mirror in the satellite body coordinate systemWherein, the sensor reference mirror coordinate system is defined as: the center of the reference mirror is the origin of coordinates, and the optical axis direction of the sensor is + ZaThe center of the axis and the reference mirror points to the direction of the connector fixedly connecting the sensor to the star body, and the direction is + XaShaft, + YaAxis and + XaAxis, + ZaThe axes form a right-handed rectangular coordinate system.
3. The fire point longitude and latitude measuring method of the fire point sensor of claim 1, wherein in the step (2), the orientation vector u of the fire point output by the sensor in the coordinate system of the reference mirror of the sensor is obtained through the direction vector information of the fire point directly output by the sensor in the coordinate system of the reference mirror of the sensorpAnd the direction vector information of the fire point directly output by the sensor in the sensor reference mirror coordinate system comprises a fire point orientation vector x, a fire point orientation vector y and the fire point time t _ fire.
4. The method as claimed in claim 1, wherein the fire point latitude and longitude of the fire point sensor is determined by the methodCharacterized in that in the step (3), if the fire point time t _ fire has no corresponding satellite attitude data, the attitude matrix corresponding to the fire point time t _ fire is obtained by combining table look-up and a linear difference method
5. The fire point longitude and latitude measuring method of the fire point sensor of claim 1, wherein in the step (3), if the fire point time t _ fire has no corresponding satellite attitude data, the satellite attitude matrix at the nearest moment to the fire point time t _ fire is obtained by looking up the table and is used as the satellite attitude matrix C of the fire point time t _ fireBO_fire。
6. The fire point longitude and latitude determination method of the fire point sensor of claim 1, wherein in the step (5), the position vector of the earth center pointing to the ground fire point is obtained by the following steps:
(1) determining a position vector of the Earth's center pointing to the center of mass of a satelliteWherein X _ fire is the coordinate of the satellite in the X-axis direction under the J2000 inertial coordinate system, Y _ fire is the coordinate of the satellite in the Y-axis direction under the J2000 inertial coordinate system, and Z _ fire is the coordinate of the satellite in the Z-axis direction under the J2000 inertial coordinate system;
(2) determining the position vector of the center point of the satellite mass center pointing to the fire point sensor under the J2000 inertial coordinate system
Wherein, COI_fireA transformation matrix for the satellite from the J2000 inertial coordinate system to the satellite orbital coordinate system; cBO_fireSatellite attitude corresponding to fire point momentA state matrix;the sensor reference mirror is a coordinate vector of the origin of the sensor reference mirror in a satellite body coordinate system;
(3) determining the position vector of the center of the earth pointing to the center point of the fire point sensor in the J2000 inertial coordinate system
(4) The earth is considered as a standard ellipsoid, and a position vector pointing to a ground fire point from the fire point sensor central point under a J2000 inertial coordinate system is obtained
A＝1+d·uI(3)2；
Visual line distance of fire point:
wherein, CPBfireAs a reference mirror coordinate system Ox of a slave sensorayazaA direction cosine matrix to the satellite body coordinate system; semi-major axis of the earth: a ise6378.145; semi-minor axis of the earth: be＝6356.76，uo、uIA, B, C, d are both temporary variables;
(5) determining a position vector of a ground center pointing to a ground fire point in a J2000 inertial coordinate system
7. The fire point longitude and latitude determination method of the fire point sensor of claim 6, wherein in the step (6), the geographic longitude L of the fire point is obtained according to the position vector of the earth center pointing to the ground fire pointn84Geographic latitude deltan84；
Geographic latitude deltan84＝mod(δn84’,π)，δn84’＝arctan(tan(δn84 *)/(1-fE)2)；
Geographic longitude Ln84＝mod(Ln84’,π)，Ln84’＝arctan2(Yn84/rn84,Xn84/rn84)；
Wherein the content of the first and second substances,
CPN_fireis a time difference nutation matrix;
Xn84＝cos(λG_fire)x1+sin(λG_fire)y1；λG_firegreenwich mean sidereal time angle;
Yn84＝-sin(λG_fire)x1+cos(λG_fire)y1；
Zn84＝z1；
δn84 *＝arcsin(Zn84/rn84)；
x1、y1、z1、Xn84、Yn84、Zn84、rn84、δn84 *are all temporary variables, fEBeing constant, mod function will convert angle Ln84' and deltan84' by adding or subtracting 2 pi, it is clipped to the range of plus or minus pi/2 and output.
Technical Field
The invention relates to a fire point sensor longitude and latitude measuring method, and belongs to the technical field of satellite attitude control.
Background
The fire detection sensor is a new sensor, the sensor directly outputs information as the vector position of the fire in the sensor reference mirror coordinate system, the fire position expected by a user is the geographic longitude and latitude position of the fire, and no method for measuring the geographic longitude and latitude of the fire exists at present.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: and obtaining the geographical longitude and latitude position of the fire point according to the output of the fire point detection sensor, the satellite orbit attitude information and the like, and providing the most direct data service for the user.
The technical scheme of the invention is as follows:
a fire point sensor longitude and latitude measuring method comprises the following steps:
(1) determining an installation matrix and an installation position of a fire detection sensor in a satellite;
(2) obtaining an orientation vector and a fire point moment of a sensor output fire point in a sensor reference mirror coordinate system;
(3) the satellite computer stores satellite attitude data, and satellite attitude information of corresponding time to a fire point is obtained by looking up a table;
(4) determining the satellite orbit position, a conversion matrix of the satellite from a J2000 inertial coordinate system to a satellite orbit coordinate system, a nutation matrix of the time and a Greenwich mean star time angle at the moment according to the fire point moment;
(5) acquiring position vector information of the geocenter pointing to the ground fire according to the satellite orbit information, the satellite attitude information, the sensor installation information and the fire azimuth vector information output by the sensor at the fire moment;
(6) and acquiring the geographical longitude and latitude information of the fire point according to the position vector of the earth center pointing to the ground fire point.
Compared with the prior art, the invention has the beneficial effects that:
the fire detection sensor is used as a novel satellite-borne intelligent sensor, the direct output information is the direction vector information of the fire in the sensor reference mirror coordinate system, the method directly outputs the geographical longitude and latitude position of the fire, the method is more visual and easy to use, the practicability of the sensor is improved, and meanwhile, the intelligentization and autonomy level of the sensor is also improved.
Drawings
FIG. 1 is a flow chart of a fire point sensor longitude and latitude determination method provided by the invention.
Detailed Description
The invention provides a fire point sensor longitude and latitude measuring method, as shown in figure 1, comprising the following steps:
1. determining the installation matrix and the installation position of the fire point sensor in the whole star: reference mirror coordinate system Ox with slave sensor as mounting matrixayazaDirection cosine matrix C to satellite body coordinate systemPBfireThe installation position is a coordinate vector of the origin of the sensor reference mirror in the satellite body coordinate system
The sensor reference mirror coordinate system is defined as: the center of the reference mirror is the origin of coordinates, and the optical axis direction of the sensor is + ZaThe central direction of the shaft and the reference mirror is + X in the direction of the connector fixedly connecting the sensor to the star bodyaShaft, + YaAxis and + XaAxis, + ZaThe axes form a right-handed rectangular coordinate system.
2. Obtaining the orientation vector of the sensor output fire point in the sensor reference mirror coordinate systemupAnd the ignition time t _ fire: the direction vector information of the fire point in the sensor reference mirror coordinate system directly output by the sensor is as the following table 1:
TABLE 1
Serial number
Content of fire
1
The fire time t _ fire, corresponding to the image exposure time
2
A fire point orientation vector X representing the projection of the fire point orientation on the X axis of the sensor reference mirror coordinate system
3
A fire point orientation vector Y which represents the projection of the fire point orientation on the Y axis of the sensor reference mirror coordinate system
The orientation vector of the fire point in the sensor reference mirror coordinate system is up＝[x y z]TWherein
3. The satellite computer stores satellite attitude data, and finds out a satellite attitude matrix C corresponding to t _ fire moment by looking up a tableBO_fire(ii) a If the fire point time t _ fire does not have corresponding satellite attitude data, acquiring an attitude matrix C corresponding to the time t _ fire by combining table look-up and a linear difference fitting methodBO_fireOr obtaining the satellite attitude matrix at the latest moment from the t _ fire moment by looking up a table as the satellite attitude matrix C at the t _ fire momentBO_fire。
4. Determining the satellite orbit position [ x _ fire y _ fire z _ fire ] at the moment according to the moment t _ fire of the fire]TTransformation matrix C of satellite from J2000 inertial coordinate system to satellite orbit coordinate systemOI_fireTime difference nutation matrix CPN_fireAnd Greenwich mean sidereal hour angle lambdaG_fire(ii) a Wherein, X _ fire is the coordinate of the satellite in the X-axis direction under the J2000 inertial coordinate system, Y _ fire is the coordinate of the satellite in the Y-axis direction under the J2000 inertial coordinate system, and Z _ fire is the coordinate of the satellite in the Z-axis direction under the J2000 inertial coordinate system.
5. According to the satellite orbit information, the satellite attitude information, the sensor installation information and the fire point azimuth vector information output by the sensor at the fire point moment, obtaining a position vector of the earth center pointing to the ground fire point:
(1) determining a position vector of the Earth's center pointing to the center of mass of a satellite
(2) Determining the representation of the position vector of the center point of the satellite mass center pointing to the fire point sensor in the J2000 inertial coordinate system
(3) Determining the representation of the position vector of the earth center pointing to the central point of the fire point sensor in the J2000 inertial coordinate systemIs composed of
(4) Considering the earth as a standard ellipsoid, determining the representation of a position vector pointing from the fire point sensor central point to the ground fire point in a J2000 inertial coordinate system
uo＝CBO_fire T·CPBfire T·up；
uI＝COI_fire T·uo；
A＝1+d·uI(3)2；
Visual line distance of fire point:
wherein, the semi-major axis of the earth: a ise6378.145, the minor axis of the earth: be＝6356.76，uo、uIA, B, C, d are temporary variables.
(5) Determining a representation of a position vector of a geocentric pointing to a ground fire in a J2000 inertial coordinate system
6. Obtaining the geographic longitude L of the fire point according to the position vector of the earth center pointing to the ground fire pointn84Geographic latitude deltan84. Utensil for cleaning buttockThe ground of the body is provided with a ground layer,
Xn84＝cos(λG_fire)x1+sin(λG_fire)y1；
Yn84＝-sin(λG_fire)x1+cos(λG_fire)y1；
Zn84＝z1；
Ln84’＝arctan2(Yn84/rn84,Xn84/rn84)；
δn84 *＝arcsin(Zn84/rn84)；
δn84’＝arctan(tan(δn84 *)/(1-fE)2)；
Ln84＝mod(Ln84’,π)；δn84＝mod(δn84’,π)；
wherein x is1、y1、z1、Xn84、Yn84、Zn84、rn84、δn84 *Are all temporary variables, fEBeing constant, mod function will convert angle Ln84' and deltan84' by adding or subtracting 2 pi, it is clipped to the range of plus or minus pi/2 and output.
Example 1
1. Installation matrix C of known fire point sensor on whole starPBfire＝[0,1,0；-1,0,0；0,0,1]And mounting location
When t is 1000.125 seconds, the moment t _ fire is 1000.125 when the sensor outputs fire, and the orientation unit vector of the fire in the coordinate system of the sensor reference mirror is up＝[0.037007109559268 0.0370071095592680.998629534754574]T；
3. Determining satellite attitude matrix C corresponding to t _ fire moment through table lookupBO_fire＝[0.99999999948125828,1.2893420485576845e-005,-2.9516826041131594e-005；-1.2893922240783673e-005,0.99999999977239318,-1.6998827341560552e-005；2.9516606861290651e-005,1.6999207920420645e-005,0.99999999941989848]；
4. Satellite orbital position at time t _ fire [ x _ fire y _ fire z _ fire]T＝[-4285.8020078297141，1631.1533849416005，-5124.1037730588559]TAnd a transformation matrix C of the satellite from the J2000 inertial coordinate system to the satellite orbit coordinate systemOI_fire＝[0.75227108918910135,-0.078435789194291963,-0.65416820111016694；0.21362294018702163,0.96828686432014266,0.12955997765868030；0.62326033709525863,-0.23720956000661980,0.74516989797318733](ii) a Time difference nutation matrix CPN_fire＝[0.99998763113715827,0.0045616475822821577,0.0019821564090035828；-0.0045616641405236960,0.99998959554866329,3.8327367635354623e-006；-0.0019821183021592925,-1.2874621168800732e-005,0.99999803551871058](ii) a Greenwich mean sidereal hour angle lambdaG_fire＝1.1896980430696951；
5. Obtaining a position vector of the earth center pointing to the ground fire point:
(1) the position vector of the earth center pointing to the center of mass of the satellite is
(2) The position vector of the center point of the satellite mass center pointing to the fire point sensor is expressed in a J2000 inertial coordinate system as follows:
(3) the position vector of the earth center pointing to the central point of the fire point sensor is expressed in a J2000 inertial coordinate system
(4) Considering the earth as a standard ellipsoid, determining the representation of a position vector pointing from the fire point sensor central point to the ground fire point in a J2000 inertial coordinate system
(5) The position vector of the earth center pointing to the ground fire point is expressed in a J2000 inertial coordinate system
6. The geographic longitude 1.5885013022905383(rad) and the geographic latitude-0.84248603778896980 (rad) of the fire are obtained from the location vector of the geocentric pointing to the fire.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种适用于小型飞行器光电系统高效扫描方法