Using DGPS as An Acceleration Sensor for Airborne Gravimetry

• 발행기관: 한국항해항만학회
• 저자명: Kaidong Zhang Lincheng Shen Xiaoping Hu Meiping Wu
• 간행물 정보: 『한국항해항만학회 학술대회논문집』2006년도 International Symposium on GPS/GNSS Vol.1, 1~6쪽, 전체 6쪽
• 주제분류: 공학 > 해양공학
• 파일형태: PDF
• 발행일자: 2006.10.24

영문 초록

In airborne gravimetry, there are two data streams. One is the specific force measured by an air/sea gravimeter or accelerometers, the other is kinematic acceleration measured by DGPS. And the difference of them provides the grav- ity disturbance information. To satisfy the requirement of most applications, an accuracy of 1mGal (1mGal=10-5m/s2) with a spatial resolution of 1km is the aim of current airborne gravimetry. There are two different methods to derive the kinematic acceleration. The generally used method is to differentiate the position twice, and the position can be calculated by commercial DGPS software. The main defect of this method is that integer ambiguities need to be fixed to get the precise position solution, but it’s not a trivial thing for long base line. And to fix integer ambiguities, the noisier iono-free measurement is used. When differentiation is applied, noise is amplified and will influence the accuracy of acceleration. The other method is to get carrier phase acceleration by differentiate the carrier phase first, and then using the ac- celeration of GPS satellite to derive the vehicle acceleration. The main advantages include that fixing integer ambi- guities is not needed anymore, position can be relaxed to about 10 meters, and smoother acceleration can be got since iono-free measurement is not needed. In some literatures, it’s considered that the dynamic performance of the second method is inferior to that of the first. Through analysis, it is found that the performance degradation in dynamic environment results from the simplifica- tion of the GPS carrier phase observable model. And an iterative algorithm is presented to compensate the model error. Using a dynamic GPS data from an aeromagnetic survey, the importance of this compensation is showed at last.

목차

1. Introduction

2. Commonly Used Carrier Phase ObservableModel

3. Error of Simplified Carrier Phase Observable Model

4. Math Model of Acceleration Determination

5. Analysis in Acceleration Domain

6. Conclusion

키워드

Airborne Gravimetry DGPS Acceleration