Method for determining the inverse of gravity correlation time

Patent metadata

Field	Value
Publication number	US-11914100-B2
Application number	US-202017421245-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Dec 17, 2019
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

The present invention discloses a method for determining an inverse of gravity correlation time. During data processing on gravity measurement of moving bases, a gravity anomaly is considered as a stationary random process in a time domain, and is described with a second-order Gauss Markov model, a third-order Gauss Markov model or an m th -order Gauss Markov model, and the inverse of gravity correlation time is an important parameter of the gravity-anomaly model, and according to a gravity sensor root mean square error, a Global Navigation Satellite System (GNSS) height root mean square error, an a priori gravity root mean square, and a gravity filter cutoff frequency during the gravity measurement of the moving bases, an inverse of gravity correlation time of the second-order, third-order or m th -order Gauss Markov model is determined. According to the method for determining an inverse of gravity correlation time provided in the present invention, a forward and backward Kalman filter during data processing on gravity measurement of moving bases can be adjusted, to obtain a high-precision and high-wavelength-resolution gravity anomaly value.

First claim

What is claimed is:

1. A method for determining an inverse of gravity correlation time, comprising:
obtaining an observation value using a global navigation satellite system (GNSS);
measuring a gravity of moving bases using a gravity sensor;
for a gravity anomaly of an m th order Gauss Markov model, according to a gravity sensor root mean square error σ f , a GNSS height root mean square error σ h , an a priori gravity root mean square σ g , and a gravity filter cutoff frequency ω c during said gravity measurement of moving bases, performing iterative calculation by using Formula (1), to obtain an inverse of gravity correlation time β, the gravity filter comprising an impulse response low-pass filter,

β
=

[

(

1
+

β
2

/

ω
c
2

)

m

⁢

ω
c

2
⁢
m

C
m

[

σ
f
2

σ
g
2

+

ω
c
4

⁢

σ
h
2

σ
g
2

]

]

1

2
⁢
m

-
1

,

where
⁢

C
m

=

2
⁢

(

2
⁢
m

-
2

)

!!

(

2
⁢
m

-
3

)

!!

;

(
1
)

(2) assuming that β<<ω c , and simplifying Formula (1) as:

β
≈

[

ω
c

2
⁢
m

C
m

[

σ
f
2

σ
g
2

+

ω
c
4

Assignees

• Univ Southeast

Inventors

• Cai Tijing

Classifications

• G01V7/06 Primary

  Analysis or interpretation of gravimetric records · CPC title

• G01V7/00

  Measuring gravitational fields or waves; Gravimetric prospecting or detecting · CPC title

• G01V7/16

  specially adapted for use on moving platforms, e.g. ship, aircraft · CPC title