EGU24-5898, updated on 08 Mar 2024
https://doi.org/10.5194/egusphere-egu24-5898
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Validation of SWOT data using airborne LiDAR off the coasts of Normandy during the fast sampling orbit phase

Laurent Froideval1, Hugo Kersimon1, Christophe Conessa1, Laurent Benoit1, Edward Salameh2, Pascal Bonnefond3, Nicolas Picot4, Imen Turki2, and Laignel Benoit2
Laurent Froideval et al.
  • 1Normandie Univ, UNICAEN, UNIROUEN, CNRS, M2C, 14000 Caen, France
  • 2Normandie Univ, UNICAEN, UNIROUEN, CNRS, M2C, 76000 Rouen, France
  • 3SYRTE, Observatoire de Paris—Université PSL, CNRS, 75000 Paris, France
  • 4CNES, Centre National d’Etudes Spatiales, 31401 Toulouse, France

The Surface Water and Ocean Topography (SWOT) altimeter will perform a continuous global water survey with unprecedented resolution and accuracy across its 3-year mission. After being launched on December 16th 2022 with a SpaceX Falcon 9 rocket from Vandenberg in California, it was successfully commissioned followed by a Calibration and Validation (Cal/Val) phase that lasted approximately between April and July 2023. During this period, numerous in-situ measurements were performed across the globe to assess the altimeter’s performance. Airborne Light Detection And Ranging (LiDAR) campaigns were conducted off the coasts of Normandy, France as part of other measurements in this region. We carried out 4 different missions, 2 in May and 2 in June, using a Leica ALS 60 airborne sensor aboard 2 different planes, a Piper Navajo and a Swearingen Fairchild Merlin. The flight plans were designed below the SWOT Ka-band Radar Interferometer (KaRIn) along and across the 1-day fast sampling ground track. Ground Control Points (GCP) were acquired under the LiDAR coverage, close to the city of Cherbourg. The plane’s trajectory was processed using CNES GINS software, using the integer Precise Point Positioning (iPPP) mode, resulting in centimetric antenna phase positioning. LiDAR data were calibrated using the GCPs with a millimetric average accuracy. First results between SWOT data and airborne LiDAR indicate very good consistency. Indeed, the differences between the SWOT LR 2 km pre-cal product and LiDAR data, averaged over a similar 2 km grid, gives centimetric standard deviation.

How to cite: Froideval, L., Kersimon, H., Conessa, C., Benoit, L., Salameh, E., Bonnefond, P., Picot, N., Turki, I., and Benoit, L.: Validation of SWOT data using airborne LiDAR off the coasts of Normandy during the fast sampling orbit phase, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5898, https://doi.org/10.5194/egusphere-egu24-5898, 2024.

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