TY - JOUR
T1 - Evaluation of multi-mode CryoSat-2 altimetry data over the Po River against in situ data and a hydrodynamic model
AU - Schneider, Raphael
AU - Tarpanelli, Angelica
AU - Nielsen, Karina
AU - Madsen, Henrik
AU - Bauer-Gottwein, Peter
N1 - Funding Information:
We would like to thank the Interregional Agency for the Po River (Agenzia Interregionale per il Fiume Po, AIPo) and DHI Italy for providing the MIKE 11 model of the Po River used in our study. Thanks to Federica Pellegrini for providing us technical information about the analyzed data for the Po River and Marco Baldo for the processing related to the geoid. Furthermore, the analyzed CryoSat-2 level 2 data was kindly provided by the National Space Institute, Technical University of Denmark. Funding from the LOTUS – Preparing Land and Ocean Take Up from Sentinel-3 project (EU FP7, grant no. 313238) and the CryoSat-2 Success over Inland Water and Land (CRUCIAL) project (ITT ESRIN/AO/1-6827/11/I-NB) is gratefully acknowledged.
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2018/2
Y1 - 2018/2
N2 - Coverage of in situ observations to monitor surface waters is insufficient on the global scale, and decreasing across the globe. Satellite altimetry has become an increasingly important monitoring technology for continental surface waters. The ESA CryoSat-2 altimetry mission, launched in 2010, has two novel features. (i) The radar altimeter instrument on board of CryoSat-2 is operated in three modes; two of them reduce the altimeter footprint by using Delay-Doppler processing. (ii) CryoSat-2 is placed on a distinct orbit with a repeat cycle of 369 days, leading to a drifting ground track pattern. The drifting ground track pattern challenges many common methods of processing satellite altimetry data over rivers. This study evaluates the observation error of CryoSat-2 water level observations over the Po River, Italy, against in situ observations. The average RMSE between CryoSat-2 and in situ observations was found to be 0.38 meters. CryoSat-2 was also shown to be useful for channel roughness calibration in a hydrodynamic model of the Po River. The small across-track distance of CryoSat-2 means that observations are distributed almost continuously along the river. This allowed resolving channel roughness with higher spatial resolution than possible with in situ or virtual station altimetry data. Despite the Po River being extensively monitored, CryoSat-2 still provides added value thanks to its unique spatio-temporal sampling pattern.
AB - Coverage of in situ observations to monitor surface waters is insufficient on the global scale, and decreasing across the globe. Satellite altimetry has become an increasingly important monitoring technology for continental surface waters. The ESA CryoSat-2 altimetry mission, launched in 2010, has two novel features. (i) The radar altimeter instrument on board of CryoSat-2 is operated in three modes; two of them reduce the altimeter footprint by using Delay-Doppler processing. (ii) CryoSat-2 is placed on a distinct orbit with a repeat cycle of 369 days, leading to a drifting ground track pattern. The drifting ground track pattern challenges many common methods of processing satellite altimetry data over rivers. This study evaluates the observation error of CryoSat-2 water level observations over the Po River, Italy, against in situ observations. The average RMSE between CryoSat-2 and in situ observations was found to be 0.38 meters. CryoSat-2 was also shown to be useful for channel roughness calibration in a hydrodynamic model of the Po River. The small across-track distance of CryoSat-2 means that observations are distributed almost continuously along the river. This allowed resolving channel roughness with higher spatial resolution than possible with in situ or virtual station altimetry data. Despite the Po River being extensively monitored, CryoSat-2 still provides added value thanks to its unique spatio-temporal sampling pattern.
KW - Calibration
KW - CryoSat-2
KW - River channel roughness
KW - Rivers
KW - Satellite altimetry
KW - Validation
UR - http://www.scopus.com/inward/record.url?scp=85037032466&partnerID=8YFLogxK
U2 - 10.1016/j.advwatres.2017.11.027
DO - 10.1016/j.advwatres.2017.11.027
M3 - Article
AN - SCOPUS:85037032466
SN - 0309-1708
VL - 112
SP - 17
EP - 26
JO - Advances in Water Resources
JF - Advances in Water Resources
ER -