Abstract:
This study evaluates whether applying radiometric calibration to Sentinel-1 GRD (Ground Range Detected) SAR images alters the accuracy of glacier surface velocity estimates obtained with an offset-tracking algorithm. The research focuses on glaciers near the Bulgarian research base on Livingston Island (Antarctica), using available in-situ GNSS (GNSS/-GNSS receiver) velocity measurements as ground truth. Two nearly identical processing chains were implemented in ESA’s SNAP software: one including radiometric calibration (producing sigma0), and one without it. All other processing steps and parameters were held constant to isolate the effect of calibration.