CN102147475B - Method and device for simultaneously determining three-dimensional geometry position and gravity potential by utilizing global position system (GPS) signal - Google Patents

Abstract

The invention relates to a method and a device for simultaneously determining three-dimensional geometry position and gravity potential, in particular to a method and a device for simultaneously determining the three-dimensional geometry position and the gravity potential by utilizing a global position system (GPS) signal. In the technical scheme, a novel method for determining the gravity potential (including elevation height) by utilizing the GPS signal is added on the basis of the traditional GPS positioning method, an observation equation between the GPS signal and the gravity potential is established, and the gravity potential is solved on the basis of a principle of least square by utilizing multiple observation data. The invention has the advantages that: heavy water level measurement and gravity measurement are not needed, and the geoidal surface is not needed to be pre-determined to determine the elevation height by utilizing the GPS positioning method, so that numerous labor power and financial resources are saved, and the restriction on measurement caused by mountains and cross oceans is avoided.

Description

Utilize gps signal to determine simultaneously method and the device thereof of three-dimensional geometry position and gravity position

Technical field

The present invention relates to a kind of method and device thereof of determining simultaneously three-dimensional geometry position and gravity position, especially relate to a kind of gps signal that utilizes and determine simultaneously method and the device thereof of three-dimensional geometry position and gravity position.

Background technology

Utilize gps signal to determine that the three-dimensional geometry position has been unusual proven technique.In order to determine gravity position or height above sea level, by classic method, need heavy measurement of the level and gravimetry, need perhaps to determine in advance that geoid surface recycles the GPS localization method and determines height above sea level, this not only needs a large amount of manpowers, financial resources, and can be very limited in the mountain area.Because gps signal comprises the three-dimensional geometry positional information, thereby can determine the three-dimensional geometry position, this is very ripe method at present.Again because gps signal comprises electromagnetic wave signal (abbreviation signal) frequency displacement information, thereby also can utilize gps signal to determine gravity position (comprising absolute elevation).This is the basis of the inventive method.

Summary of the invention

The present invention solves heavy measurement of the level and the gravimetry of the existing needs of prior art, need perhaps to determine in advance that geoid surface recycles the GPS localization method and determines height above sea level, this not only needs a large amount of manpowers, financial resources, and the technical matters that can be very limited in the mountain area etc.; A kind of do not need heavy measurement of the level and gravimetry are provided, do not need to determine in advance that geoid surface recycles the GPS localization method and determines height above sea level yet, thereby saved a large amount of manpowers, financial resources, and determined simultaneously method and the device thereof of three-dimensional geometry position and gravity position at the gps signal that utilizes that also is not subjected to mountain area and foreign Restriction of the Measuring over strait.

Above-mentioned technical matters of the present invention is mainly solved by following technical proposals:

A kind of gps signal that utilizes is determined the method for three-dimensional geometry position and gravity position simultaneously, it is characterized in that, comprises the following steps:

Step 1 utilizes that GPS receiver collection observation is at least 4 satellites, phase place that continue at least 20 minutes and signal frequency shift observed reading, and the sampling rate of observed reading is 1 second, and each observed reading is to there being the observation moment;

Step 2 utilizes phase observations value and precise ephemeris in step 1 to determine survey station three-dimensional geometry position, ground by the three-dimensional geometry position determination module;

Step 3 utilizes EGM2008 gravity field model and precise ephemeris to determine that gps satellite is corresponding to observed reading gravitation position constantly by satellite gravitation position determination module;

Step 4, by survey station gravity position determination module, the three-dimensional geometry position determined in step 2 and step 3 Satellite place gravitation position information are introduced among gps signal phase place-frequency displacement observation equation, the gravity position of survey station and clocking error are introduced among gps signal phase place-frequency displacement observation equation as undetermined parameter, add simultaneously the model corrections such as single order Doppler shift, ionosphere frequency displacement, troposphere frequency displacement, set up gps signal phase place-frequency displacement observation equation, and obtain the gravity position of survey station based on the principle of least square;

Step 5, based on the survey station gravity position of finding the solution, the gravity position on the geoid surface utilizes the Bruns formula to determine the absolute elevation of survey station as benchmark by the absolute elevation determination module;

Step 6 is by message output module output three-dimensional geometry position and absolute gravity position and absolute elevation.

Determine simultaneously the method for three-dimensional geometry position and gravity position at the above-mentioned gps signal that utilizes, in described step 4,

The phase place of gps signal-frequency displacement observation equation

${\mathrm{\Φ}}_A=\frac{f}{c}{\mathrm{\ρ}}_A=\frac{f_0}{c}{\mathrm{\ρ}}_A+\frac{\mathrm{\Δf}}{c}{\mathrm{\ρ}}_A$

Wherein, Φ _AThe phase observations value of the gps signal at survey station A place, f ₀With f be respectively that signal transmits and receives frequency, ρ _ABe the star distance between sites, c is the light velocity in vacuum.

Determine simultaneously the method for three-dimensional geometry position and gravity position at the above-mentioned gps signal that utilizes, in described step 4, Δ f=f-f ₀Be the signal frequency shift amount, determined by following equation

Δf＝Δf _d+Δf _i+Δf _t+Δf _c+ΔΔf _g (1)

Wherein, Δ f _d, Δ f _iWith Δ f _tBe respectively classical Doppler shift, ionosphere frequency displacement and troposphere frequency displacement, provide by model value; Clocking error Δ f _cIt is undetermined parameter; Δ f _gBe the gravity frequency displacement, provided by following formula

$\mathrm{\Δ}{f}_g=f\frac{W_A-W_S^i}{c^2}$

The gravity position W at survey station place wherein _AUndetermined parameter, W _S ⁱAt t along rail flight satellite _iGravity position constantly can be expressed as

$W_S^i=W[x_S\left(t_i\right),y_S\left(t_i\right),z_S\left(t_i\right)]$

Wherein, x _S(t _i), y _S(t _i), z _S(t _i) be that satellite is at t _iThe coordinate in Earth central inertial is constantly.

Determine simultaneously the method for three-dimensional geometry position and gravity position at the above-mentioned gps signal that utilizes, comprise the GPS receiver that connects successively, three-dimensional geometry position determination module, satellite gravitation position determination module, survey station gravity position determination module, absolute elevation determination module and message output module.

Therefore, the present invention has following advantage: 1. determine on the basis of three-dimensional geometry position in the existing GPS of utilization technology, realize simultaneously utilizing gps signal to determine gravity position (comprising absolute elevation), realize that GPS two level measuring systems 2. do not need heavy measurement of the level and gravimetry, do not need to determine in advance that geoid surface recycles the GPS localization method and determines height above sea level yet, thereby saved a large amount of manpowers, financial resources, and also be not subjected to mountain area and foreign Restriction of the Measuring over strait.

Description of drawings

Accompanying drawing 1 is a kind of schematic diagram of the present invention;

Accompanying drawing 2 is a kind of workflow diagrams of the present invention;

Embodiment

Below by embodiment, and by reference to the accompanying drawings, technical scheme of the present invention is described in further detail.

Embodiment:

Utilize gps signal to determine simultaneously the method for three-dimensional geometry position and gravity position, comprise the following steps:

Step 1 utilizes that GPS receiver collection observation is at least 4 satellites, phase place that continue at least 20 minutes and signal frequency shift observed reading, and the sampling rate of observed reading is 1 second, and each observed reading is to there being the observation moment;

Step 2 utilizes phase observations value and precise ephemeris in step 1 to determine survey station three-dimensional geometry position, ground by the three-dimensional geometry position determination module;

Step 3 utilizes EGM2008 gravity field model and precise ephemeris to determine that gps satellite is corresponding to observed reading gravitation position constantly by satellite gravitation position determination module;

Step 4, by survey station gravity position determination module, the three-dimensional geometry position determined in step 2 and step 3 Satellite place gravitation position information are introduced among gps signal phase place-frequency displacement observation equation, the gravity position of survey station and clocking error are introduced among gps signal phase place-frequency displacement observation equation as undetermined parameter, add simultaneously the model corrections such as single order Doppler shift, ionosphere frequency displacement, troposphere frequency displacement, set up gps signal phase place-frequency displacement observation equation, and obtain the gravity position of survey station based on the principle of least square;

The model corrections such as the single order Doppler shift of this step, ionosphere frequency displacement, troposphere frequency displacement, concrete operation step is:

Step 4.1 calculates classical Doppler shift value by classical Doppler shift determining unit by land station position and the sp3 precise ephemeris that provides in the obs file;

Step 4.2 calculates the troposphere frequency shift value by troposphere frequency displacement determining unit by land station position and the sp3 precise ephemeris that provides in the obs file;

Step 4.3 by the frequency shift value of frequency displacement determining unit in ionosphere by L1 in the obs file and L2 carrier wave, utilizes the double frequency null method to calculate the ionosphere frequency displacement;

The required model of using of paper above-mentioned steps 4.1 to 4.3 and correlation formula:

Classical Doppler shift is to cause the variation of the frequency of the satellite-signal that land station receives because satellite and surface-based observing station have relative velocity, and specifically formula is:

$\mathrm{\Δf}=f-f_s=-\frac{f_s}{c}\frac{\mathrm{ds}}{\mathrm{dt}}---\left(2\right)$

Wherein c is the light velocity in vacuum, f _sBe respectively transmission frequency and receive frequency with f, in the unit interval, research station and intersatellite variable in distance are ds/dt.

Provide in the header file of the coordinate of land station by the obs file, co-ordinates of satellite is obtained with newton's interpolation method (getting suitable order) by the sp3 precise ephemeris.The Newton method interpolation produces multinomial coefficient by constructing each jump business, forms polynomial expression take unknown point and interpolation point geometry site as independent variable, and computing velocity is fast, and efficient is high.Concrete formula is as follows:

The difference coefficient formula:

$f[x_0,x_1...x_n]=\frac{f[x_0,x_1...x_{n-2},x_n]-f[x_0,x_1...x_{n-2},x_{n-1}]}{x_n-x_{n-1}}---\left(3\right)$

Newton's interpolation formula:

f(x)＝f(x ₀)+f[x ₀，x ₁](x-x ₀)

+f[x ₀，x ₁，x ₂](x-x ₀)(x-x ₁)+...

+f[x ₀，x ₁...x _n](x-x ₀)(x-x ₁)...(x-x _n-1) (4)

The position of satellite provides in inertial coordinates system; Land station's coordinate represents in body-fixed coordinate system usually.Therefore, need to do earth rotation and correct, be actually coordinate transform.Coordinate transform is provided by following equation

X _t＝Xcosa+Ysina (5)

Y _t＝-Xsina+Ycosa

In formula, a=2 π t/ (3600 * 24), t are the time that satellite-signal spends from the satellite transmission to the land station, and (X, Y) is the position of satellite in inertial system, (X _t, Y _t) be the position of satellite in ground is admittedly.

The troposphere frequency displacement is the impact of the tropospheric delay of gps signal in communication process, can obtain with the Tropospheric Models difference, and optional model has (1) SAASTMOINEN; (2) MODIFIELDHOPIFIELD; (3) SIMPLIFIED HOPIFIELD.The Hopifield model formation of the simplification of calculating troposphere phase place range delay is as follows:

${\mathrm{\Δ\ρ}}_{\mathrm{trop}}=\mathrm{\Δ}{S}_d+{\mathrm{\ΔS}}_w=\frac{K_d}{\sin {(E^2+6.25)}^{\frac{1}{2}}}+\frac{K_w}{\sin {(E^2+2.25)}^{\frac{1}{2}}}---\left(6\right)$

Wherein

$K_d=155.2\×{10}^{-7}\frac{P_s}{T_s}(h_d-h_s),$ $K_w=155.2\×{10}^{-7}\·\frac{4810}{{T_S}^2}{e}_s(h_w-h_s)---\left(7\right)$

In formula, Δ ρ _TropBe phase delay, E is elevation angle, h _d=401386+148.72 (T-273.16), h _w=11000m, h _sLand station's elevation, take rice as unit, P _sAir pressure, take millibar as unit; Wherein

e _s=RHexp (37.2465+0.21366T-0.0002568908T ²), T _sFor doing temperature, T is observation temperature constantly, adopts absolute temperature scale (ATS), unit K, and RH is relative humidity.In the situation that do not measure the survey station Meteorological Elements, adopt given standard pressure calculation of parameter, wherein P _sGet 1013.25mBar, T _sGet 291.15K, RH gets 50.

Can obtain t constantly according to above model ₁Troposphere phase place range delay Δ ρ _Trop(t ₁) and moment t ₂Tropospheric delay Δ ρ _Trop(t ₂), can obtain at last the correction formula of troposphere frequency displacement:

${\mathrm{\Δf}}_{\mathrm{trop}}=-\frac{f}{c}\frac{\∂\mathrm{\Δ}{\mathrm{\ρ}}_{\mathrm{trop}}}{\∂t}\≈-\frac{f}{c}\frac{{\mathrm{\Δ\ρ}}_{\mathrm{trop}2}-{\mathrm{\Δ\ρ}}_{\mathrm{trop}1}}{t_2-t_1}=-\frac{{\mathrm{\Δ\ρ}}_{\mathrm{trop}2}-\mathrm{\Δ}{\mathrm{\ρ}}_{\mathrm{trop}1}}{t_2-t_1}=-\frac{{\mathrm{\Δ\ρ}}_{\mathrm{trop}2}-{\mathrm{\Δ\ρ}}_{\mathrm{trop}1}}{(t_2-t_1)c}f---\left(8\right)$

The cancellation of the available double frequency null method of the impact of ionosphere frequency displacement, this is to be inversely proportional to due to the ionosphere frequency displacement of gps signal and frequency itself, and other all frequency displacements and frequency itself are directly proportional, as shown in the formula:

$f_j^{\mathrm{obs}}=\mathrm{\α}{\tilde{f}}_j+\frac{\mathrm{\χ}}{{\tilde{f}}_j},j=\mathrm{1,2}---\left(9\right)$

$\left\{\begin{array}{c}\mathrm{\α}=\frac{k(k\stackrel{\‾}{f_1^{\mathrm{obs}}}-\stackrel{\‾}{f_2^{\mathrm{obs}}})}{{\tilde{f}}_1(k^2-1)}\\ \mathrm{\χ}=\frac{\stackrel{\‾}{f_1^{\mathrm{obs}}}-k\stackrel{\‾}{f_2^{\mathrm{obs}}}}{1-k^2}{\tilde{f}}_1\end{array}\right.---\left(10\right)$

Wherein, χ is ionosphere frequency displacement item, and α is other frequency displacement item sum, k=f ₁/ f ₂, the true transmission frequency of signal is used respectively

With

Expression.List system of equations by the D1 on L1 and L2 carrier wave and D2 observed reading, can solve α and χ; Can extract the gravity frequency shift signal according to α.

Have definite relation between the movement of signal frequency and gravity potential difference, i.e. gravity position frequency displacement equation is provided by following formula:

$W-W_s=c^2\frac{\mathrm{\Δf}}{f_0}---\left(11\right)$

In formula, f ₀Be intrinsic transmission frequency, Δ f is the gravity frequency displacement, Satellite gravity position W _SCan be asked for by the low order gravity field model.Low order gravity field model W _SBe the known quantity that is input in program, it is low order gravitation position V and potential of centrifugal force Q sum: W _S=V+Q.

Concrete correlation computations step of the present invention and principle are as follows:

Utilize gps signal to determine the model omission of three-dimensional geometry position, can find in general textbook.The model of determining gravity position (comprising absolute elevation) is as follows:

I) the phase observations equation of model gps signal

${\mathrm{\Φ}}_A=\frac{f}{c}{\mathrm{\ρ}}_A=\frac{f_0}{c}{\mathrm{\ρ}}_A+\frac{\mathrm{\Δf}}{c}{\mathrm{\ρ}}_A---\left(1\right)$

Wherein, Φ _AThe phase observations value of the gps signal at survey station A place, f ₀With f be respectively that signal transmits and receives frequency, ρ _ABe the star distance between sites, c is the light velocity in vacuum, Δ f=f-f ₀Be the signal frequency shift amount, determined by following equation

Δf＝Δf _d+Δf _i+Δf _t+Δf _c+Δf _g (2)

Wherein, Δ f _d, Δ f _iWith Δ f _tBe respectively classical Doppler shift, ionosphere frequency displacement and troposphere frequency displacement, provide by model value; Clocking error Δ f _cIt is undetermined parameter; Δ f _gBe the gravity frequency displacement, provided by following formula

$\mathrm{\Δ}{f}_g=f\frac{W_A-W_S^i}{c^2}---\left(3\right)$

The gravity position W at survey station place wherein _AUndetermined parameter, W _S ⁱAt t along rail flight satellite _iGravity position constantly can be expressed as

$W_S^i=W[x_S\left(t_i\right),y_S\left(t_i\right),z_S\left(t_i\right)]---\left(4\right)$

Wherein, x _S(t _i), y _S(t _i), z _S(t _i) be that satellite is at t _iThe coordinate (being provided by precise ephemeris) in Earth central inertial is constantly.By equation (1)-(4), can write out following observation equation

${\mathrm{\Φ}}_A=\frac{f_0}{c}{\mathrm{\ρ}}_A+\frac{{\mathrm{\Δf}}_d+{\mathrm{\Δf}}_i+{\mathrm{\Δf}}_t}{c}{\mathrm{\ρ}}_A+\frac{1}{c}{\mathrm{\ρ}}_A{\mathrm{\Δf}}_c+\frac{W_A-W[x_S\left(t_i\right),y_S\left(t_i\right),z_S\left(t_i\right)]}{c^3}{\mathrm{\ρ}}_{A}f---\left(5\right)$

II) because satellite orbit (precise ephemeris) is known, thereby can determine that according to the gravity field model EGM2008 of up-to-date issue satellite is at t _iGravity position constantly:

W[x _S(t _i)，y _S(t _i)，z _S(t _i)]＝V[x _S(t _i)，y _S(t _i)，z _S(t _i)]+Q[x _S(t _i)，y _S(t _i)，z _S(t _i)] (6)

Q[x wherein _S(t _i), y _S(t _i), z _S(t _i)] be potential of centrifugal force, provided by following formula

$Q[x_S\left(t_i\right),y_S\left(t_i\right),z_S\left(t_i\right)]=\frac{{\mathrm{\ω}}^2}{2}[x_S^2\left(t_i\right)+y_S^2\left(t_i\right)]---\left(7\right)$

ω=7.292115 * 10 wherein ^-5Rad/s is the earth rotation angular speed, V[x _S(t _i), y _S(t _i), z _S(t _i)] be gravitation potential of earth, can be according to the III that states later) step determines.

III) based on the EGM2008 model, can consolidate on ground the lower definite gravitation potential of earth of spherical co-ordinate (r, θ, λ) in reference frame:

$V(r,\mathrm{\θ},\mathrm{\λ})=\frac{\mathrm{GM}}{r}[1+\underset{n=1}{\overset{2159}{\mathrm{\Σ}}}{\left(\frac{a}{r}\right)}^n\underset{m=0}{\overset{n}{\mathrm{\Σ}}}({\stackrel{\‾}{C}}_{\mathrm{nm}}\cos \mathrm{m\λ}+{\stackrel{\‾}{S}}_{\mathrm{nm}}\sin \mathrm{m\λ}){\stackrel{\‾}{P}}_{\mathrm{nm}}\left(\cos \mathrm{\θ}\right)]---\left(8\right)$

Wherein GM is the earth's core constant (known), and a=6378136.572m is the terrestrial equator mean radius, P _nm(cos θ) is regular association Legendre function, C _nmAnd S _nmRegular spherical harmonic coefficient, by the EGM2008 model.

IV) with the coordinate (x under Earth central inertial system _S, y _S, z _S) coordinate (r, θ, λ) that is converted under body-fixed coordinate system can determine t at any time by equation (8) _iGravitation position (the marking t when omitting here at place, satellite in orbit place _i), and then can determine t at any time according to equation (6) and (7) _iThe gravity position at place, satellite in orbit place.The coordinate conversion equation is as follows:

x _S＝rcosλsinθ

y _S＝rsinλsinθ

z _S＝rcosθ (9)

It is inversely transformed into

$r=\sqrt{{x_S}^2+{y_S}^2+{z_S}^2}$

$\mathrm{\θ}={\cos }^{-1}\left(\frac{z_S}{r}\right)$

$\mathrm{\λ}={\tan }^{-1}\left(\frac{y_S}{x_S}\right)---\left(10\right)$

V) all can set up an observation equation (5) for each observed reading, so obtain a large amount of redundant observation equations.Find the solution based on the principle of least square, can obtain the gravity position W at the place of survey station A on ground _A

VI) utilize geopotential constant W on geoid surface ₀=62636855.580, can adopt following Bruns formula

$H_A=\frac{W_0-W_A}{\stackrel{\‾}{\mathrm{\γ}}}---\left(11\right)$

Determine the absolute elevation H that survey station A is ordered _A, wherein γ is the mean normal gravity on reference ellipsoid.

According to above-mentioned model, can utilize gps signal to determine gravity position and the absolute elevation of ground survey station.In conjunction with the method for existing definite three-dimensional geometry position, can realize two measurements of GPS again, namely utilize gps signal to determine simultaneously three-dimensional geometry position and gravity position (comprising absolute elevation).

In the present invention, the device that adopts comprises successively the GPS receiver 1 that connects, three-dimensional geometry position determination module 2, satellite gravitation position determination module 3, survey station gravity position determination module 4, absolute elevation determination module 5 and message output module 6.

Specific embodiment described herein is only to the explanation for example of the present invention's spirit.Those skilled in the art can make various modifications or replenish or adopt similar mode to substitute described specific embodiment, but can't depart from spirit of the present invention or surmount the defined scope of appended claims.

Claims (3)

1. one kind is utilized gps signal to determine simultaneously the method for three-dimensional geometry position and gravity position, it is characterized in that, comprises the following steps:

Step 1 utilizes that GPS receiver collection observation is at least 4 satellites, phase place that continue at least 20 minutes and signal frequency shift observed reading, and the sampling rate of observed reading is 1 second, and each observed reading is to there being the observation moment;

Step 2 utilizes phase observations value and precise ephemeris in step 1 to determine survey station three-dimensional geometry position, ground by the three-dimensional geometry position determination module;

Step 3 utilizes EGM2008 gravity field model and precise ephemeris to determine that gps satellite is corresponding to observation gravitation position constantly by satellite gravitation position determination module;

Step 4, by survey station gravity position determination module, the three-dimensional geometry position determined in step 2 and step 3 Satellite are being introduced corresponding to observation gravitation position information constantly among gps signal phase place-frequency displacement observation equation, the gravity position of survey station and clocking error are introduced among gps signal phase place-frequency displacement observation equation as undetermined parameter, add simultaneously single order Doppler shift, ionosphere frequency displacement, troposphere frequency displacement model correction, set up gps signal phase place-frequency displacement observation equation, and obtain the gravity position of survey station based on the principle of least square;

Step 5, based on the survey station gravity position of finding the solution, the gravity position on the geoid surface utilizes the Bruns formula to determine the absolute elevation of survey station as benchmark by the absolute elevation determination module;

Step 6 is by three-dimensional geometry position, gravity position and the absolute elevation of message output module output survey station loca.

2. the gps signal that utilizes according to claim 1 is determined the method for three-dimensional geometry position and gravity position simultaneously, it is characterized in that, and in described step 4,

The phase place of gps signal-frequency displacement observation equation

${\mathrm{\Φ}}_A=\frac{f}{c}{\mathrm{\ρ}}_A=\frac{f_0}{c}{\mathrm{\ρ}}_A+\frac{\mathrm{\Δf}}{c}{\mathrm{\ρ}}_A$

Wherein, Φ _AThe phase observations value of the gps signal at survey station A place, f ₀With f be respectively that signal transmits and receives frequency, ρ _ABe the star distance between sites, c is the light velocity in vacuum, Δ f=f-f ₀It is the signal frequency shift amount;

In described step 4, Δ f=f-f ₀The signal frequency shift amount, f ₀With f be respectively that signal transmits and receives frequency, determined by following equation

Δf＝Δf _d+Δf _i+Δf _t+Δf _c+Δf _g

Wherein, Δ f _d, Δ f _iWith Δ f _tRespectively classical Doppler shift, ionosphere frequency displacement and troposphere frequency displacement; Clocking error Δ f _cIt is undetermined parameter; Δ f _gBe the gravity frequency displacement, provided by following formula

$\mathrm{\Δ}{f}_g=f\frac{W_A-W_S^i}{c^2}$

Wherein c is the light velocity in vacuum, and the gravity position W at survey station place _AUndetermined parameter,

At t along rail flight satellite _iGravity position constantly can be expressed as

$W_S^i=W[x_S\left(t_i\right),y_S\left(t_i\right),z_S\left(t_i\right)]$

Wherein, x _S(t _i), y _S(t _i), z _S(t _i) be that satellite is at t _iThe coordinate in Earth central inertial is constantly, wherein, " t _iImplication constantly " is: i observation moment point, wherein, and i=1,2 ..., N.

3. device that utilizes method claimed in claim 1, it is characterized in that, comprise the GPS receiver (1), three-dimensional geometry position determination module (2), satellite gravitation position determination module (3), survey station gravity position determination module (4), absolute elevation determination module (5) and the message output module (6) that connect successively.

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