Long baselines laser ranging is realized without control point satellite Precise Position System and methodTechnical field
The present invention relates to satellite remote sensing technology, in particular it relates to which a kind of Long baselines laser ranging is realized without control point satellitePrecise Position System and method.
Background technology
The information that satellite remote sensing technology obtains can be divided into three classes：Qualitative, positioning and quantitative.It is " fixed in above-mentioned three category informationPosition " information directly reflects the spatial correspondence between remote sensing information and target, is the important of remote sensing qualitative and quantitative analysisPremise and basis.At present, external satellite is under the conditions of having control point, and positioning for ground precision can reach a meter magnitude, during no control pointPositioning for ground precision can reach ten meters, hundred meters of magnitude, and domsat positioning for ground level and the U.S., France, Japan etc. also haveLarger gap.
Under-developed area about 90% belongs to Wu Tuqu in the world today, and Pillarless caving satellite positioning for ground precision is veryLOS point precision is depended in big degree, and LOS point precision determines with satellite orbital position, flight attitude determines, structureUnpredictable shake is associated during thermal deformation and satellite flight with mechanism.Developed by Current hardware, technique etc.Limitation, orbit determination, accuracy of attitude determination only by improving satellite platform etc. have been difficult to meet high accuracy to correct optical axis sensing deviationPositioning for ground requirement.
The content of the invention
For in the prior art the defects of, in order to improve satellite positioning for ground precision, promote high-precision satellite surveying and mapping, photographyDeng field development, the advantage based on laser radar precision ranging of the invention, it is proposed that nothing is realized in a kind of Long baselines laser rangingControl point satellite accurate positioning method.
A kind of Long baselines laser ranging provided according to an aspect of the present invention is realized and is accurately positioned without control point satelliteSystem, including satellite platform, speculum and laser radar；The laser radar and the speculum are arranged at the satellite and put downOn platform.
Preferably, the satellite platform includes satellite platform body, head rod and the second connecting rod；Described firstOne end of connecting rod and one end of second connecting rod connect the both sides of the satellite platform body respectively.
Preferably, the laser radar includes generating laser, first laser signal receiver, the reception of second laser signalDevice and the 3rd laser signal receivers；The generating laser is arranged in the satellite platform body, the Laser emissionThe laser pulse of device transmitting is reflected earthward by speculum；The first laser signal receiver, second laser signal receiveDevice is separately positioned on the other end of the head rod and the other end of second connecting rod；3rd laser signal connectsDevice is received to be arranged on the satellite platform body；The first laser signal receiver, the second laser signal receiver withAnd the reception direction of the 3rd laser signal receivers is directed to ground.
Preferably, the speculum uses electric drive rotatable mirror.
Preferably, the generating laser uses Nd:YAG solid state lasers, two kinds of ripples of 1064nm and 532nm can be launchedIt is long.
Preferably, the head rod and the second connecting rod use length as 1 meter to 100 meters of rigid rod.
The Long baselines laser ranging provided according to another aspect of the present invention is realized to be accurately positioned without control point satelliteThe satellite accurate positioning method of system, comprises the following steps：
Step 1：By generating laser to ground or low-altitude detection objective emission laser pulse, and launch time is recorded simultaneouslyt0；
Step 2：First laser signal receiver D1, second laser signal receiver D2And the 3rd laser signal receiversD3The laser signal returned from ground return point P is received respectively, and record receives the time t of signal respectively1、t2、t3；
Step 3：First laser signal receiver D is calculated respectively1, second laser signal receiver D2And the 3rd laser letterNumber receiver D3To the distance r of ground return point1、r2And r3；
Step 4：The position coordinates of Laser emission moment satellite is obtained by the Big Dipper or GPS location, is believed according to three laserThe installation matrix of number receiver, is calculated position coordinates D of three laser signal receivers at the Laser emission moment1(x1,y1,z1)、D2(x2,y2,z2)、D3(x3,y3,z3)；
Step 5：By position coordinates D1(x1,y1,z1)、D2(x2,y2,z2)、D3(x3,y3,z3) and r1、r2、r3Substitute into equationGroup, you can obtain the three-dimensional coordinate P (x, y, z) of ground return point.
Preferably, the step 3 usesCalculate r1、r2And r3, wherein c is the light velocity, riFor laser signalReceiver is to the distance of ground return point, tiThe time of signal, t are received for laser signal receivers0For laser pulse emission whenBetween.
Preferably, equation group is in the step 5
Compared with prior art, the present invention has following beneficial effect：
1st, high accuracy positioning over the ground of the invention does not need the high-precision control point on traditional ground, but activelyGround, ground " control point " coordinate is accurately obtained, can effectively solve less-developed uncovered area does not have ground control pointOrientation problem, and the orientation problem without obvious surface mark such as ocean, mountain forest；
2nd, the present invention does not need accurate Satellite attitude information, also not dependent on the thermal change to satellite structure, mechanismShape Accurate Calibration, only according to the track location information for knowing satellite, (position coordinates of satellite passes through the alignment systems such as the Big Dipper, GPSPositioning can reach very high-precision), you can realize high-precision positioning for ground, greatly reduce requirement to related satellite hardware andThe complexity of system；
3rd, the present invention utilizes laser distance measurement method, and the range information measured by co-ordinates of satellite, laser radar can be accurateThe coordinate information of ground point is resolved, simple in construction, algorithm is simple, can be equipped on photography, mapping, laser three-dimensional imaging etc. and defendStar, realize that high-precision three-dimensional positions over the ground；
4th, the present invention can obtain the three-dimensional accuracy coordinate of positioning target point, and satellite can be realized to low latitude moving targetHigh accuracy positioning, the three-dimensional coordinate information of low flyer (such as guided missile, aircraft) is obtained, can be with continuous tracing modeSpeed, the orbit information of target are obtained, there is great application value.
Brief description of the drawings
The detailed description made by reading with reference to the following drawings to non-limiting example, further feature of the invention,Objects and advantages will become more apparent upon：
Fig. 1 is that the structural representation without control point satellite Precise Position System is realized in medium-long baselines laser ranging of the present invention；
Fig. 2 is that medium-long baselines laser ranging of the present invention is realized without the pinpoint measuring principle figure of control point satellite.
In figure：
1 is satellite platform body；
2 be generating laser；
3 be speculum；
4 be head rod；
5 be the second connecting rod；
6 be first laser signal receiver；
7 be second laser signal receiver；
8 be the 3rd laser signal receivers.
Embodiment
With reference to specific embodiment, the present invention is described in detail.Following examples will be helpful to the technology of this areaPersonnel further understand the present invention, but the invention is not limited in any way.It should be pointed out that the ordinary skill to this areaFor personnel, without departing from the inventive concept of the premise, various modifications and improvements can be made.These belong to the present inventionProtection domain.
In the present embodiment, as shown in Figure 1 and Figure 2, Long baselines laser ranging provided by the invention is realized without control point satellitePrecise Position System includes satellite platform, speculum 3 and laser radar.The laser radar and the speculum 3 are arranged atOn the satellite platform.The satellite platform includes satellite platform body 1, the connecting rod 5 of head rod 4 and second；It is describedOne end of head rod 4 and described one end of second connecting rod 5 connect the both sides of the satellite platform body 1 respectively.It is described to swashOptical radar includes generating laser 2, first laser signal receiver 6, the laser signal of second laser signal receiver 7 and the 3rdReceiver 8；The generating laser 2 is arranged in the satellite platform body, the laser pulse that the generating laser 2 is launchedReflected earthward by speculum 3；The first laser signal receiver 6, second laser signal receiver 7 are separately positioned on instituteState the other end of head rod 4 and the other end of the second connecting rod 5；3rd laser signal receivers 8 are arranged on instituteState on satellite platform body 1；The first laser signal receiver 6, the second laser signal receiver 7 and the described 3rdThe reception direction of laser signal receivers 8 is directed to ground.3rd laser signal receivers 8 are arranged on satellite platform body 1,Specific reception system can also be used with main load (such as optical camera) light path reception altogether.The speculum 3 usesElectric drive rotatable mirror, to realize continuous, the quick regulation in laser pulse light beam direction.Speculum 3 can control laserThe deflection of beam direction, realize the positioning of difference over the ground in certain visual field, can also realize positioning to moving target withTracking.The connecting rod 5 of head rod 4 and second uses length as 1 meter to 100 meters of rigid rod.Rail is carried out in satelliteDeploy after road work, fixed after expansion with satellite platform angle, the length of specific bar, can be according to different satellites times with platform angleSpecific design is done in business requirement.
The generating laser 2 uses Nd:YAG solid state lasers, two kinds of wavelength of 1064nm and 532nm can be launched.Such asLaser three-D cartographic satellite uses the laser of 1064nm wavelength, and optical photography satellite uses the laser of 532nm wavelength.
For the transmitting laser of different wave length, using different laser detectors：The selection Si-APD detections of 532nm wavelengthDevice, 1064nm selection InGaAS-APD detectors.Energy of lasers is mJ magnitudes, and the angle of divergence is μ rad magnitudes, according to different meshPulsed laser energy and the angle of divergence can be adjusted flexibly in mark characteristic and object height.
The connecting rod 5 of head rod 4 and second is equivalent to " Long baselines " in surveying, measurement process in the present inventionAs shown in Fig. 2 specific implementation step is as follows：
Step 1：By generating laser to ground or low-altitude detection objective emission laser pulse, and launch time is recorded simultaneouslyt0；
Step 2：First laser signal receiver D1, second laser signal receiver D2And the 3rd laser signal receiversD3The laser signal returned from ground return point P is received respectively, and record receives the time t of signal respectively1、t2、t3；
Step 3：First laser signal receiver D is calculated respectively1, second laser signal receiver D2And the 3rd laser letterNumber receiver D3To the distance r of ground return point1、r2And r3, wherein：C is the light velocity, riFor laser signalReceiver is to the distance of ground return point, tiThe time of signal, t are received for laser signal receivers0For laser pulse emission whenBetween；
Step 4：The position coordinates of Laser emission moment satellite is obtained by the Big Dipper or GPS location, is believed according to three laserThe installation matrix of number receiver, is calculated position coordinates D of three laser signal receivers at the Laser emission moment1(x1,y1,z1)、D2(x2,y2,z2)、D3(x3,y3,z3)；
Step 5：By position coordinates D1(x1,y1,z1)、D2(x2,y2,z2)、D3(x3,y3,z3) and r1、r2、r3Substitute into followingEquation group, you can obtain the three-dimensional coordinate P (x, y, z) of ground return point.
The present invention meets without control point, the requirement of high-precision positioning for ground, comprising two parts of satellite platform and laser radar,Laser radar load is made up of a generating laser and three laser signal receivers, and satellite platform body is respectively to two phasesOpposite direction stretches out two connecting rods, and a laser signal receivers, the 3rd laser signal receivers are installed in the end of every barOn satellite platform.Method provided by the invention utilizes laser radar range principle, measures three receivers and target pointDistance, then substitute into the three-dimensional coordinate of three receivers under the coordinate system that is connected, you can pass through solving equations and obtain target pointThree-dimensional coordinate.The present invention realizes high-precision positioning for ground using Long baselines laser distance measurement method, calculates simply, simple structure is rightThe attitude information dependence of satellite high-precision is small, greatly reduces the requirement to hardware such as star sensors, can apply to photographCartographic satellite, linear array or face battle array laser three-D cartographic satellite, have on the satellites such as the optical imagery of high-precision positioning for ground demand.
The specific embodiment of the present invention is described above.It is to be appreciated that the invention is not limited in above-mentionedParticular implementation, those skilled in the art can make various deformations or amendments within the scope of the claims, this not shadowRing the substantive content of the present invention.