Sentinel1A

Sentinel-1A is the first satellite in the European Copernicus Programme's fleet of Sentinel missions. Launched on April 3, 2014, from the European Spaceport in Kourou, French Guiana, it is a C-band synthetic aperture radar (SAR) satellite. Its primary role is to provide continuous, all-weather, day-and-night imagery of the Earth's surface. This allows for consistent monitoring of land and ocean surfaces, crucial for a wide range of applications.

The satellite operates in a sun-synchronous orbit, ensuring consistent illumination conditions for optical sensors (though Sentinel-1A is radar-based). Its SAR instrument can acquire data in various modes, including Interferometric Wide Swath (IWS), which offers a wide coverage of 250 km, and Stripmap (SM), providing higher resolution data over narrower strips. This versatility enables Sentinel-1A to detect changes in the Earth's surface with millimeter-level precision.

Key applications of Sentinel-1A data include monitoring of sea ice extent and drift, mapping of oil spills, tracking of land subsidence and uplift, support for disaster management (e.g., flood mapping and earthquake damage assessment), and monitoring of agricultural land. The data is freely and openly accessible to users worldwide, facilitating research, policy-making, and operational services. Sentinel-1A is part of a two-satellite constellation, later joined by Sentinel-1B, which was launched in 2016.