The images of Russia’s Ozero Nayval Lagoon and surrounding rivers show multiple views from Copernicus satellites. The first is a 10-m resolution ‘camera-like’ image captured on 29 October 2020 by Copernicus Sentinel-2. The peninsula lies on the eastern part of the Bearing Straits. The land-bound lagoon, various river and lake features are clearly visible. The image is marked with the ground track of Copernicus Sentinel-6 as it crosses the region.
The second is a radar image captured on 29 November 2020 by Copernicus Sentinel-1 in interferometric wide swath mode and processed to 10 m resolution. The radar look direction is from the right with layover effects seen on the mountainous region to the left of the image. The lagoon has frozen over and numerous cracks are visible in the ice. Ocean swell and wind sea roughness are also seen in the ocean with some wave reflection and refraction on the southern coastal areas.
The next image uses Copernicus Sentinel-6 pulse-limited low-resolution mode data for the same area. In this mode, similar to Jason-3, the strongest radar reflections appear as overlapping parabola features, but no discrimination of the ground can be made.
Overlying the third image, the Copernicus Sentinel-6 Poseidon-4 fully-focused synthetic aperture radar image reveals features of the Ozero Nayvak Peninsular in fine detail. The high performance and low noise of Poseidon-4 when processed using these ESA-developed techniques reveals exceptional results. In this example, the altimeter data were first processed at a resolution of 1.1 m in the azimuth direction (left to right) and <0.4 m in the range direction (vertical). These data are then further multi-looked in azimuth to reduce speckle noise providing an image at a resolution of ~30 m. The radar backscatter power is coded by colour as a function of across-track range and clearly reveals the vertical elevation of sea ice in the lagoon and low-lying river and lake features. Unlike the Sentinel-1 image, the Sentinel-6 Poseidon-4 radar is illuminating the scene from the north and in this case, ocean wave structure and refraction at the coastline can be clearly seen.
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