Traffic jam in the Gulf of Suez caused by the obstruction as seen by the Sentinel-1 satellite
SAR is a rapidly expanding earth observation technology and business model, partly because it can see through clouds and is day/night agnostic. As long as there is enough solar+battery power, local (spacecraft) computing power and bandwidth to the ground it is highly competitive with optical Earth observation for logistics (Where is all the stuff?) and topography (Has the ground risen or lowered a little bit?). See all the answers to How can ICEYE-X1 capture 2D high resolution SAR images in "tens of seconds"? for more, and How (the heck) was coherent synthetic aperture radar (SAR) implemented using photographic emulsion aboard Apollo 17? and How do radio astronomers avoid having their receivers burned out by ground-imaging radar from satellites? for fun.
There are several bright spots in the images; this is probably due to certain configurations of metal surfaces on the ships that either produce specular reflection (glint off of a mirror) or a corner-reflector like effect (the opposite of stealth aircraft shape design).
Question: But why are the star-like artifacts on certain very bright reflections star-like in shape? We see artifacts like this in optical telescopes (like the Hubble (optical) space telescope) with four vanes holding the secondary mirror (for more on that see below), but there are no secondary mirrors or vanes in SAR. What exactly causes this effect?
[...] The two identical Copernicus Sentinel-1 satellites carry radar instruments to provide an all-weather, day-and-night supply of imagery of Earth’s surface, making it ideal to monitor ship traffic.
The sea surface reflects the radar signal away from the satellite, and makes water appear dark in the image. This contrasts with metal objects, in this case the ships in the bay, which appear as bright dots in the dark waters.
left: "New shot of Proxima Centauri, our nearest neighbour" Source right: from Does this telescope only have a 4 blade aperture? in Photography SE, originally from 20 years of Hubble Space Telescope optical modeling using Tiny Tim (paywalled, also available here and see this page) Note that the lines in the image going one way are produced by the vanes going the other way in the telescope.