DocumentCode :
3682697
Title :
A study of non-stochastic IMU errors in strapdown airborne gravimetry
Author :
D. Becker;M. Becker
Author_Institution :
Chair of Physical and Satellite Geodesy (PSG) Technical University of Darmstadt Franziska-Braun-Str. 7 64287 Darmstadt Germany
fYear :
2015
Firstpage :
1
Lastpage :
18
Abstract :
Strapdown airborne gravimetry is the determination of the Earth´s gravity acceleration from an aircraft, using a strapdown inertial measurement unit (IMU) in combination with an aiding sensor (typically GNSS). Several publications show, that a modern navigation-grade IMU in combination with two-frequency phase-differential GNSS enables the gravity determination to the level of several micro-g. We hereby present a quantitative analysis of the impact of non-stochastic IMU errors on the gravity determination, based on simulated gravity flights with realistic dynamics. Several error types are discussed, including biases, scale factors, cross-couplings and misalignments of the sensor triads, each for both the accelerometers and gyroscopes. In particular, it is shown that the on-line estimation of in-flight accelerometer bias changes is not possible for this application, due to the inseparability against changes in the gravity signal. For each type of stochastic IMU errors, a threshold value is provided where the average error of the estimated gravity reaches 1 mGal. As an example, these threshold values are compared to actual accelerometer calibration results of an iMAR RQH unit. It is shown for this device, that a proper calibration is required in order to reach gravity estimate accuracies at the 1 mGal level.
Keywords :
"Gravity","Global Positioning System","Accelerometers","Sensors","Accuracy","Calibration"
Publisher :
ieee
Conference_Titel :
Inertial Sensors and Systems Symposium (ISS), 2015 DGON
Electronic_ISBN :
2377-3480
Type :
conf
DOI :
10.1109/InertialSensors.2015.7314272
Filename :
7314272
Link To Document :
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