Application of retracked satellite altimetry for inland hydrologic studies

Abstract

We explored the application of satellite radar altimetry for the monitoring of small inland bodies of water and hydrologic studies using a water-detection algorithm, optimally retracked TOPEX/POSEIDON data at 10-Hz sampling, and investigated the use of radar backscatter to improve land cover classification. The procedure was demonstrated over Manitoba and south-western (SW) Ontario, and the Amazon River Basin study regions. Compared with an L-band synthetic aperture radar data generated water-land cover mask, the water-detection algorithm detected more water points over the Amazon basin. High correlation of 0.98 between the retracked 10-Hz altimetry and the gauge measurements in Manitoba confirmed that the retracked TOPEX data are more accurate than the non-retracked data, and with higher along-track spatial resolution by virtue of its higher sampling at 10 Hz.

Acknowledgements

This research is funded by grants from NSF's Hydrology program, NGA's NURI program, and the Ohio State University Climate, Water and Carbon Program. We acknowledge NASA and CNES for providing the TOPEX/POSEIDON (GDR and SDR) data products; LEGOS, USDA and NASA/GSFC for providing high-level radar altimetry data products; ANA Brazil and Environment Canada for providing the river stage gauge data used for the study. We thank Mike Durand, the guest editor, and an anonymous reviewer for the constructive comments which improved the manuscript.