In recent years, the use of a strapdown Inertial Measurement Unit (IMU) for airborne gravimetry has proven itself to be an accurate and resilient measurement system, improving the operational flexibility. The main concern is erroneous long-wavelength information in the resulting estimates, which is suspected to originate from uncompensated long-term drift of the accelerometers, probably originating from temperature variation. For this reason, iMAR navigation has designed a temperature stabilisation box, which allows for temperature stabilisation of their IMU systems. On a regional airborne gravity survey over the Kattegat Sea between Denmark and Sweden, such a temperature stabilised strapdown IMU was operated alongside a traditional spring-type platform-stabilised gravity system from ZLS. An analysis of the difference in gravity estimates at cross-over locations yielded a mean value of 0.3 mGal for the iMAR system with an indicated accuracy of 1.0 mGal. The temperature stabilisation unit therefore effectively limits the accelerometer drift and improves the long-wavelength information. However, a straightforward merging approach, adjusting the line-based mean values of the iMAR estimates to match that of the ZLS estimates, improved the accuracy to 0.8 mGal. This indicates that the long-wavelength information of the stabilised-platform system is still superior to that of the strapdown system.
Bibliographical noteThis is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
- Airborne gravimetry
- Strapdown gravimetry
- Inertial measurement unit
- Temperature stabilisation
Jensen, T. E., Olesen, A. V., Forsberg, R., Olsson, P-A., & Josefsson, Ö. (2019). New results from strapdown airborne gravimetry using temperature stabilisation. Remote Sensing, 11(22), . https://doi.org/10.3390/rs11222682