Ship Monitoring from space: SUEZ

Below you can see the example timelapse of Suez Canal ship traffic, made with a Sentinel-1 custom composite visualization. You can observe the moving ships as time passes.

Sentinel-1 is a pair of European radar imaging (SAR) satellites launched in 2014 and 2016. Its 6 days revisit cycle and ability to observe through clouds makes it perfect for sea and land monitoring, emergency response due to environmental disasters, and economic applications. This dataset represents the global Sentinel-1 GRD archive, from beginning to the present, converted to cloud-optimized GeoTIFF format.

Sentinel-1 AWS-IW-VVVH: SAR urban

The Interferometric Wide (IW) swath mode is the main acquisition mode over land and satisfies the majority of service requirements. It acquires data with a 250 km swath at 5 m by 20 m spatial resolution (single look). IW mode captures three sub-swaths using Terrain Observation with Progressive Scans SAR (TOPSAR). With the TOPSAR technique, in addition to steering the beam in range as in ScanSAR, the beam is also electronically steered from backward to forward in the azimuth direction for each burst, avoiding scalloping and resulting in homogeneous image quality throughout the swath.

TOPSAR Sub-Swath Acquisition

TOPSAR mode replaces the conventional ScanSAR mode, achieving the same coverage and resolution as ScanSAR, but with a nearly uniform Signal-to-Noise Ratio and Distributed Target Ambiguity Ratio.

The azimuth resolution is reduced compared to SM due to the shorter target illumination time of the burst. Using the sweeping azimuth pattern, each target is seen under the same antenna pattern, independently from its azimuth position in the burst image. By shrinking the azimuth antenna pattern, as seen by a target on the ground, scalloping effects on the image can be reduced. Bursts are synchronised from pass to pass to ensure the alignment of interferometric pairs.

IW SLC products contain one image per sub-swath and one per polarisation channel, for a total of three (single polarisation) or six (dual polarisation) images in an IW product.

Each sub-swath image consists of a series of bursts, where each burst has been processed as a separate SLC image. The individually focused complex burst images are included, in azimuth-time order, into a single sub-swath image with black-fill demarcation in between. There is sufficient overlap between adjacent bursts and between sub-swaths to ensure continuous coverage of the ground as provided in GRD products. The images for all bursts in all sub-swaths are resampled to a common pixel spacing grid in range and azimuth while preserving the phase information.

IW SLC Bursts andSub-Swaths

After burst and sub-swath merging, the full product can be created, as is the case for the GRDH products shown in Figure 3. The TOPSAR technique greatly reduces scalloping effects over conventional ScanSAR.

IW GRDH Product

Sentinel-1 uses wide area coverage with improved revisit times and is able to potentially detect smaller ships than Envisat’s ASAR instrument. The mission’s ability to observe in all weather and in day or night time, makes it ideal for precise cueing and location of ship activities at sea, allowing for more efficient and cost-effective use of other security assets, such as patrol aircraft and ships. Data relevant to ship detection are transmitted by the satellite in real-time for reception by local collaborative ground stations supporting European and national services.

Illustration of vessels observed between Gibraltar and Algesiras on September 2017, Copernicus Sentinel Data [2017]
Classical ship wake pattern on SAR imagery (S-1A Stripmap, Copernicus Data [2015]) with a local wind speed of 2 m/s. A/ Kelvin “V” wave dark and bright on each side, B/ Narrow “V” wave, D/ Turbulent wave

Some other interesting stuff you can do:

Ice Monitoring
Oil polution Monitoring
Marine Winds
Etc…

https://en.wikipedia.org/wiki/Suez_Canal
https://www.sentinel-hub.com/explore/eobrowser/
https://custom-scripts.sentinel-hub.com/#sentinel-1
https://sentinels.copernicus.eu/web/sentinel/user-guides/sentinel-1-sar/acquisition-modes
https://sentinels.copernicus.eu/web/sentinel/user-guides/sentinel-1-sar/acquisition-modes/interferometric-wide-swath
https://sentinels.copernicus.eu/web/sentinel/user-guides/sentinel-1-sar/applications/maritime-monitoring
https://www.youtube.com/watch?v=XQe_petggwA&ab_channel=SaankhyaLabs


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