TY - JOUR
T1 - Airborne Gravimetry of GEOHALO Mission
T2 - Data Processing and Gravity Field Modeling
AU - Lu, Biao
AU - Barthelmes, Franz
AU - Petrovic, Svetozar
AU - Förste, Christoph
AU - Flechtner, Frank
AU - Luo, Zhicai
AU - He, Kaifei
AU - Li, Min
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Airborne gravimetry is a crucial method to improve our knowledge about the Earth gravity field, especially in hard‐to‐access regions. Generally, the accuracy of airborne gravimetry is several milligals, which is suitable for filling the so‐called polar gaps in satellite‐derived global gravity field models. Here some investigations based on airborne gravity measurements from the GEOHALO mission over Italy are presented. To subtract the vertical accelerations from the values measured by the gravimeter, four different versions of kinematic accelerations were derived from Global Navigation Satellite Systems (GNSS) recordings. To remove the high‐frequency noise, a low‐pass filter with a cutoff wavelength of 200 s was applied to both Chekan‐AM measurements and kinematic accelerations from GNSS. To investigate how future airborne gravity campaigns could be designed, a dedicated flight track was repeated two times showing that the equipment worked well also at higher altitude and speed. From the final best results follows an RMS of gravity differences at crossover points of 1.4 mGal, which, according to the law of error propagation, implies the accuracy of a single measurement to be urn:x-wiley:jgrb:media:jgrb52455:jgrb52455-math-0001 mGal. To demonstrate how a satellite‐only gravity field model can be improved by airborne measurements, a gravity field model for the GEOHALO region has been computed. To compute also an improved regional geoid model, the point mass modeling (PMM) and the remove‐compute‐restore (RCR) technique, using a recent satellite‐only model and residual terrain modeling (RTM), were applied. Finally, GNSS/leveling points have been used to check the quality of the regional point mass model.
AB - Airborne gravimetry is a crucial method to improve our knowledge about the Earth gravity field, especially in hard‐to‐access regions. Generally, the accuracy of airborne gravimetry is several milligals, which is suitable for filling the so‐called polar gaps in satellite‐derived global gravity field models. Here some investigations based on airborne gravity measurements from the GEOHALO mission over Italy are presented. To subtract the vertical accelerations from the values measured by the gravimeter, four different versions of kinematic accelerations were derived from Global Navigation Satellite Systems (GNSS) recordings. To remove the high‐frequency noise, a low‐pass filter with a cutoff wavelength of 200 s was applied to both Chekan‐AM measurements and kinematic accelerations from GNSS. To investigate how future airborne gravity campaigns could be designed, a dedicated flight track was repeated two times showing that the equipment worked well also at higher altitude and speed. From the final best results follows an RMS of gravity differences at crossover points of 1.4 mGal, which, according to the law of error propagation, implies the accuracy of a single measurement to be urn:x-wiley:jgrb:media:jgrb52455:jgrb52455-math-0001 mGal. To demonstrate how a satellite‐only gravity field model can be improved by airborne measurements, a gravity field model for the GEOHALO region has been computed. To compute also an improved regional geoid model, the point mass modeling (PMM) and the remove‐compute‐restore (RCR) technique, using a recent satellite‐only model and residual terrain modeling (RTM), were applied. Finally, GNSS/leveling points have been used to check the quality of the regional point mass model.
KW - ITC-ISI-JOURNAL-ARTICLE
UR - https://ezproxy2.utwente.nl/login?url=https://doi.org/10.1002/2017JB014425
UR - https://ezproxy2.utwente.nl/login?url=https://library.itc.utwente.nl/login/2017/isi/lu_air.pdf
U2 - 10.1002/2017JB014425
DO - 10.1002/2017JB014425
M3 - Article
VL - 122
SP - 10,586-10,604
JO - Journal of geophysical research. Solid earth
JF - Journal of geophysical research. Solid earth
SN - 2169-9313
IS - 12
ER -