Unlocking Sentinel-1 SAR Data for the Antarctic Region

Sentinel-1 Synthetic Aperture Radar (SAR) data is extremely valuable for Antarctic research due to its ability to observe the continent through cloud cover and polar darkness. Unfortunately, researchers struggle to make full use of Sentinel-1 SAR because it is not readily available as standardised analysis ready data. The Digital Earth Antarctica Program will support researchers by producing consistent, high-quality, analysis ready SAR products over the Antarctic region. This presentation will discuss work conducted by the Digital Earth Antarctica team to understand the barriers that researchers face in using the Sentinel-1 archive, the challenges of producing high-quality SAR analysis ready data, and a pathway to unlocking the Sentinel-1 archive for the Antarctic region.



The Digital Earth Antarctica team have identified that a key challenge for researchers is accessing high-quality data in the correct format for specific analyses. For example, interferometric SAR (InSAR) can measure changes in Antarctic glaciers, coastal and sea-ice zones. There are areas that are well captured by Sentinel-1's Extra Wide (EW) mode, filling in significant gaps in the data available from the higher resolution Interferometric Wide (IW) mode. However, fewer than 1% of all EW acquisitions in the archive are in the single-look complex (SLC) format required for InSAR, locking off this avenue of investigation to Antarctic researchers. Normalised radar backscatter, produced from the Sentinel-1 ground range detection (GRD) product, is also valuable for assessing changes across Antarctica. Sentinel-1's GRD products for both IW and EW mode require further processing to produce geolocated analysis ready data. This includes applying complex processes such as orbital corrections, atmospheric corrections, geocoding, geometric terrain correction and radiometric terrain correction. These additional processing steps prevent researchers from easily conducting long-term studies and time series analyses, as the data cannot be consistently compared over time without them.



The barriers to using Sentinel-1 faced by Antarctic researchers and data quality issues in Sentinel-1 products can both be addressed by developing analysis ready data for Antarctica. The Digital Earth Antarctica team will produce data that meets the analysis ready data standards developed by the Committee on Earth Observation Satellites (CEOS). The team have investigated multiple pipelines for producing CEOS analysis ready data products such as SAR Normalised Radar Backscatter (NRB), Geocoded Single-Look Complex (GSLC) and InSAR (standard in review). The team have also considered how to support Antarctic researchers in accessing these products through open-source software such as the Open Data Cube. Based on this work, the team will present a summary of the challenges associated with producing ARD for Antarctica and a roadmap for producing and providing these products to Antarctic researchers and the broader Earth observation community.



Presented at the 2025 IEEE International Geoscience and Remote Sensing Symposium.

Tags: Antarctica, Physical Geography and Environmental Geoscience not elsewhere classified, Published_External, analysis ready data, earth observation
Organization: Geoscience Australia Data