Summary of the invention
The present invention proposes the method for a kind of moon laser altimeter in the error analysis of rail detection data; This disposal route can be to measuring the processing repeat a little to search for quickly with data in the moon elevation mass data; And the measurement data to moon southern hemisphere and northern hemisphere same latitude district can compare analysis, provides the distribution situation that moon vertical error is handled back residual error and standard deviation.For the source of further analyzing the laser altimeter measuring error provides foundation.
The present invention adopts following technical scheme: a kind of moon laser altimeter comprises the steps: in the method for rail detection data error analysis
Obtain laser altimeter altitude figures file: the track of China's Chang'e I satellite is a polar circle moon track, and track is one around moon circumference.The every spot elevation data of sampling at a distance from a second of the laser altimeter that carries; The scientific exploration data of laser altimeter during the Chang'e I lunar exploration are 1400 rails altogether; Form 1400 track files, said track fileinfo comprises elevation sampling time, the moon longitude of sampled point, latitude, the altitude figures information of laser altimeter.
Step 1:From 1400 track files that moon laser altimeter records, select respectively and belong to
L1 ~ h1Spot elevation data recording in the zone,
L1Be regional lower boundary,
L1=60+step* (i-1), unit is a latitude, and
L1>=60 H1Be regional coboundary,
H1=60+step*i, unit is a latitude, and
H1≤90,
StepFor step-length and
Step=0.1,
I=1,2,3 ..., 300, obtaining latitude is that 60 ° ~ 90 ° moonscapes are cut apart 300 zones of formation and corresponded respectively to the data recording of the spot elevation in 300 zones; Simultaneously,
From 1400 track files that moon laser altimeter records, select respectively and belong to
L2 ~ h2Spot elevation data recording in the zone,
L2Be regional lower boundary,
L2=-60-step*i, unit is a latitude, and
L2>=-90 H2Be regional coboundary,
H2=-60-step* (i-1), unit is a latitude, and
H2≤-60,
StepFor step-length and
Step=0.1,
I=1,2,3 ..., 300, obtaining latitude is that-60 ° ~-90 ° moonscapes are cut apart 300 zones of formation and corresponded respectively to the data recording of the spot elevation in 300 zones;
Step 2:Search for duplicate measurements point in each zone one by one, the method for search duplicate measurements point is in each zone:
Step 2.1Respectively with each zone as pending zone, the order
k=1,
Step 2.2Choose any spot elevation in the pending zone,
Step 2.3Find spherical distance between the selected spot elevation less than all spot elevations in 200 meters the pending zone, and with said all spot elevations and a said selected spot elevation as 1 duplicate measurements point point set
,
Expression the
kIndividual duplicate measurements point point set is put point set with duplicate measurements again
In spot elevation from pending zone, remove, otherwise, if in the pending zone arbitrarily the distance between the left point greater than 200 meters, simultaneously, order: current
k=
N, then the duplicate measurements point search finishes,
Said spherical distance
does
RFor with the radius of sphericity of reference ellipsoid as positive spheroid,
,
Be respectively 2 latitudes on the sphere;
Be respectively on the sphere 2 longitude,
Step 2.4Order
k=
k + 1, return step 2.2,
Step 3: calculate each regional residual sum standard deviation one by one, the method for calculating each regional residual sum standard deviation is:
Step 3.1Calculate current each duplicate measurements point point set that is present in the zone to be calculated
In the average of spot elevation
And residual error
, wherein, duplicate measurements point point set
In the average of spot elevation
,
Be point set
In
jThe height value of individual point,
nBe point set
Total number of middle spot elevation, duplicate measurements point point set
In the residual values of each spot elevation do
,
Step 3.2Calculate the standard deviation in the zone to be calculated
,
,
NRepresent regional duplicate measurements point point set sum to be calculated,
mAll spot elevation sums in the zone to be calculated in the expression,
Step 3.3Residual values and standard deviation to being obtained by step 3.1, step 3.2. are carried out the rejecting of gross error, and following method is adopted in the rejecting of gross error: with residual absolute value greater than 3 times of standard deviations promptly
Altitude figures point as the gross error point, from the zone, reject the data recording of the spot elevation corresponding, and from duplicate measurements point point set with gross error point
The middle gross error point of rejecting returns step 3.1; If all residual absolute values are smaller or equal to 3 times of standard deviations
Promptly
, then preserve all the spot elevation residual values in current zone to be calculated and the whole regional standard difference result in zone to be calculated, and carry out the calculating of the ultimate criterion difference in final zone to be calculated,
Step 4:Altitude figures result to latitude same latitude district, north and south, moon the two poles of the earth compares, the analytical error characteristic distributions, and method is:
The regional residual error of result of calculation contrast moon south poles same latitude according to step 3 distributes, and draws each spot elevation place moon longitude of residual sum of each spot elevation in each zone, the distribution plan of latitude; Each the regional standard deviation that obtains according to step 3, and drawing area and standard deviation distribution plan.
Advantage of the present invention:
(1) the error analysis research to moon laser altimeter altitude figures is to carry out first; To the error analysis of laser altimeter detection data research, the design of the various useful load (lunar observation instrument) that can carry for the lunar exploration satellite provides theoretical direction and reference data in accuracy requirement.
(2) handle through the moonscape zoning being carried out altitude figures, can realize effectively handling fast mass data.
(3) the present invention can compare analysis to the measurement data in moon southern hemisphere and northern hemisphere same latitude district, provides the distribution situation of residual error and standard deviation after the moon altitude figures Error processing.For the source of further analyzing the laser altimeter measuring error provides foundation.
(4) pass through error result and Analysis of error source; Orbit data in conjunction with moonik; The distribution situation of spatial and temporal distributions angle inverting lunar space environment thermal environment, electromagnetic environment and the high energy particle radiation belt that also can produce from measuring error, and the probability of the incident of undergoing mutation in the environment of lunar space.
(5) can the method be used for the error analysis of the scientific exploration data of other celestial bodies.
Embodiment:
Below in conjunction with accompanying drawing the present invention is further specified:
A kind of method that is used for moon laser altimeter in the error analysis of rail detection data is characterized in that concrete steps are following:
Obtain laser altimeter altitude figures file: the track of China's Chang'e I satellite is a polar circle moon track, and track is one around moon circumference.The every spot elevation data of sampling at a distance from a second of the laser altimeter that carries; The scientific exploration data of laser altimeter during the Chang'e I lunar exploration are 1400 rails altogether; Form 1400 track files, said track fileinfo comprises elevation sampling time, the moon longitude of sampled point, latitude, the altitude figures information of laser altimeter.
Laser altimeter carries on the Chang'e I satellite; Sample track to the menology elevation also is to get back to the polar circle moon track of polar region again from the polar region, so the closer to the polar region, number of data points distributes intensive more; Measurement repeats a little many more; Low latitude district in the moon, image data point distributes sparse more, measure repeat a little few more.Repeat a little search and the scheme of altitude figures Error processing and analysis so adopt two polar region altitude figuress records to carry out each area inner measuring by the latitude zoning.
Step 1:From 1400 track files that moon laser altimeter records, select respectively and belong to
L1 ~ h1Spot elevation data recording in the zone,
L1Be regional lower boundary,
L1=60+step* (i-1), unit is a latitude, and
L1>=60 H1Be regional coboundary,
H1=60+step*i, unit is a latitude, and
H1≤90,
StepFor step-length and
Step=0.1,
I=1,2,3 ..., 300, obtaining latitude is that 60 ° ~ 90 ° moonscapes are cut apart 300 zones of formation and corresponded respectively to the data recording of the spot elevation in 300 zones;
Be illustrated in figure 1 as the sectional view of moonscape Region Segmentation, 70 °~70.1 ° in the moon Northern Hemisphere latitude that indicates among the figure, 70.1 °~70.2 ° is wherein two zones in above-mentioned 300 zones.
Simultaneously, from 1400 track files that moon laser altimeter records, select respectively and belong to
L2 ~ h2Spot elevation data recording in the zone,
L2Be regional lower boundary,
L2=-60-step*i, unit is a latitude, and
L2>=-90 H2Be regional coboundary,
H2=-60-step* (i-1), unit is a latitude, and
H2≤-60,
StepFor step-length and
Step=0.1,
I=1,2,3 ..., 300, obtaining latitude is that-60 ° ~-90 ° moonscapes are cut apart 300 zones of formation and corresponded respectively to the data recording of the spot elevation in 300 zones;
Be illustrated in figure 1 as the moon the Southern Hemisphere latitude-70 that indicates in the sectional view of moonscape Region Segmentation °~-70.1 ° ,-70.1 °~-70.2 ° is wherein two zones in-60 ° ~-90 ° moonscapes 300 zones cutting apart formation to latitude.
Step 2:Search for duplicate measurements point in each zone one by one, the method for search duplicate measurements point is in each zone:
Step 2.1Respectively with each zone as pending zone, the order
k=1,
Step 2.2Choose any spot elevation in the pending zone,
Step 2.3Find spherical distance between the selected spot elevation less than all spot elevations in 200 meters the pending zone, and with said all spot elevations and a said selected spot elevation as 1 duplicate measurements point point set
,
Expression the
kIndividual duplicate measurements point point set, for example shown in Figure 2 is that the measurement that searches in institute's favored area repeats a point set by region longitude expansion synoptic diagram.Again point set is put in duplicate measurements
In spot elevation from pending zone, remove, otherwise, if in the pending zone arbitrarily the distance between the left point greater than 200 meters, simultaneously, order: current
k=
N, then the duplicate measurements point search finishes,
Said spherical distance
does
RFor with the radius of sphericity of reference ellipsoid as positive spheroid,
,
Be respectively 2 latitudes on the sphere;
Be respectively on the sphere 2 longitude,
Step 2.4Order
k=
k + 1, return step 2.2,
Step 3: calculate each regional residual sum standard deviation one by one, the method for calculating each regional residual sum standard deviation is:
Step 3.1Calculate current each duplicate measurements point point set that is present in the zone to be calculated
In the average of spot elevation
And residual error
, wherein, duplicate measurements point point set
In the average of spot elevation
,
Be point set
In
jThe height value of individual point,
nBe point set
Total number of middle spot elevation, duplicate measurements point point set
In the residual values of each spot elevation do
,
Step 3.2Calculate the standard deviation in the zone to be calculated
,
,
NRepresent regional duplicate measurements point point set sum to be calculated,
mAll spot elevation sums in the zone to be calculated in the expression,
Step 3.3Residual values and standard deviation to being obtained by step 3.1, step 3.2. are carried out the rejecting of gross error.
According to orbit Design and the actual rail data of surveying, the orbit altitude of CE-1 is (200 ± 25) km scope, about 20 km of the maximum topographic relief of moonscape, so the rational distance measurement value of laser altimeter also should be within this scope., signal to noise ratio (S/N ratio) smooth owing to abnormal signal, menology noise, lunar surface accident of terrain crossed reasons such as low, and some distance measurement value reading has exceeded this scope, need weed out.The elimination of rough difference method has Lay with special criterion, Dixon criterion and Vladimir Romanovskiy criterion etc.; Because number of data points is very many; Be hundreds of or several thousand points; And lunar surface altitude figures Normal Distribution for guaranteeing safe rejecting and the high precision and the high efficiency of data, has adopted Lay to handle with special criterion here.Levin culling gross error to adopt special guidelines: the residual absolute value greater than three times the standard deviation
![Figure 541575DEST_PATH_IMAGE015](https://patentimages.storage.googleapis.com/77/a7/f0/cf7ca84a158dd6/541575DEST_PATH_IMAGE015.png)
is
elevation data point as a gross error points removed from the regional point of gross errors and corresponding elevation point data logging, and from the repeated measurements little collection
to exclude gross errors point, return to step 3.1; if all residuals absolute value less than or equal to 3 times the standard deviation
is
, then save the current zone to be calculated for all elevation points to be calculated residuals and standard deviation of the entire area of zone results the final area to be calculated and the final standard deviation is calculated,
Step 4:Altitude figures result to latitude same latitude district, north and south, moon the two poles of the earth compares, the analytical error characteristic distributions, and method is:
The regional residual error of result of calculation contrast moon south poles same latitude according to step 3 distributes, and draws each spot elevation place moon longitude distribution plan of residual sum of each spot elevation in each zone; Each the regional standard deviation that obtains according to step 3, and drawing area and standard deviation distribution plan.
Like latitude area-88.0 °~-88.1 ° of longitude-residual error distribution scatter diagram such as Fig. 3,88.0 °~88.1 ° longitude-residual error distribution scatter diagram such as Fig. 4 of latitude area.88.0 °~88.1 ° zones of latitude search to measure and repeat 649 of point set sums, and after handling through step 3, the regional standard difference is 71.21m, and the altitude figures that relates to is counted 1240; Latitude-88.0 °~-88.1 ° of zones searches to measure and repeats 895 of point set sums, and after handling through step 3, the regional standard difference is 102.17m, and it is 1778 that the altitude figures that relates to is counted.
60 °~90 ° each regional standard deviation result of calculation such as Fig. 5 and Fig. 6 of being cut apart of polar region, north and south latitude scope; Wherein in 60 °~90 ° scopes of Fig. 5 middle latitude, there are two regional standard differences obviously bigger than normal; They are 73 °~73.1 ° of latitude areas; The regional standard difference is 219.55m, 73.1 °~73.2 ° of latitude areas, and the regional standard difference is 166.93m.A regional standard difference near lunar North Pole point among Fig. 5 is often big, is clear contrast two polar region standard deviations, and this zone is not shown in the diagram, and it is 89.8 °~89.9 ° of latitude areas, and the regional standard difference is 293.00m; Have two regional standard differences obviously bigger than normal in Fig. 6 middle latitude-60 °~-90 ° of scopes, they are latitude areas-75.4 °~-75.5 °, and the regional standard difference is 186.46m; Latitude area-65.5 °~65.6 °, the regional standard difference is 185.47m, in Fig. 6 above-mentioned 2 standard deviations bigger than normal; Lunar South Pole is unusual big zone near limit two regional standard differences in addition; Poor for each regional standard of clear contrast two polar regions, this two zone is not shown in the diagram, and they are; Latitude area-89.7 °~-89.8 °, the regional standard difference is 460.89m, latitude area-89.8 °~-89.9 °, the regional standard difference is 793.59m.
And before SELENE; The high latitude area that surpasses 86 ° does not have height measured data; Have only the laser acquisition data of SELENE and CE-1 to cover the face whole month; Therefore drawn standard deviation result of calculation comparison diagram Fig. 7 that 86 °~90 ° intervals of two polar region latitudes have about 80 intervals altogether (wherein-89.7 °~-89.8 ° do not put into figure with-89.8 °~-89.9 °) specially with 89.8 °~89.9 ° three zones of latitude; Abscissa value is on the occasion of being 86 °~90 ° 40 zones that are divided into of latitude scope among the figure; Abscissa value be negative value be latitude scope-86 °~-90 ° of 40 zones that are divided into, the direction that the horizontal ordinate absolute value increases is towards the moon two extreme directions.Be that horizontal ordinate is that 40 zone is 89.9~90 ° of zones of latitude.From Fig. 7, the zone is during near moon the two poles of the earth, and the standard deviation in lunar South Pole zone is bigger than normal.
Step 3 is calculated whole 595 (600 zones altogether; Remove latitude area-89.7 °~-89.8 ° ,-89.8 °~-89.9 ° and unusual big zone of 89.8 °~89.9 ° three standard deviations of latitude area; And 89.9 °~90 ° of latitude areas with-89.9 °~-90 ° in the elevation posting field is not arranged) zone and respective standard difference be listed among Fig. 8 by the two poles of the earth areal distribution in proper order; The direction that the horizontal ordinate absolute value increases is towards the moon two extreme directions; The whole difference of two polar region standard deviations is apparent in view near the position of two polar region limits; The average difference in 298 zones that Fig. 8 middle latitude scope is 60 °~90 ° is 74.16m; The average difference in 297 zones of latitude scope-60 °~-90 ° of scopes is 83.67m, and whole latitude scope-60 °~-90 ° is that 60 °~90 ° inner region standard deviations of south latitude latitude scope are bigger than normal.
Cause 60 °~90 ° reasons that the range criterion difference is bigger than normal of polar region, moon north and south latitude; Except that the landform that will consider the moon itself changes evident characteristic; If other orbit data in conjunction with moonik; Also can study from the distribution situation of spatial and temporal distributions angle inverting lunar space environment thermal environment, electromagnetic environment and the high energy particle radiation belt of measuring error generation, and the probability of the incident of undergoing mutation in the environment of lunar space.