I used to enjoy clicking through to the ESA Sentinel images, but then they kinda dried up for a while, or it was very hit and miss for updates. It would be nice to have regular daily or weekly upload. Our planet is so beautiful, as many of these Sentinel images show.
I was curious what instruments this use, looks like a special form of radar? Does this mean it effectively gives us very accurate height maps regardless of cloud coverage, and is able to differentiate between what surface material it's seeing?
> Radar instruments can image Earth’s surface through clouds, precipitation, regardless of sunlight, making them particularly well suited for monitoring polar regions. The Sentinel-1C and -1D satellites also carry an Automatic Identification System (AIS) instrument – improving the mission capacity to detect ships and sea pollution. The Sentinel-1D AIS was also activated as the satellite passed over Antarctica capturing the presence of ships in these extreme areas.
Ideally you want to have a large collecting area (aperture) for radar to get good resolution. But it isn't practical to put a big radar dish in space. So they use a small aperture and simulate a larger one by sweeping out an area over time and using some clever maths. Hence 'synthetic aperture radar'.
Even the high-res version (20 MB) of the Bremen image seems to be about 17-25m per pixel based on the 50m wide airport runway being about 2-3 pixels wide in the image.
Copernicus browser claims 10x10 meter pixels (which seems to be correct) but the actual resolution of the radar is supposed to be 5m-x-20m for the standard IW mode. I assume "high resolution" here means the data should have 5m x 5m resolution (Strip Map mode) which in Copernicus browser claims 3.5x3.5m pixels.
The images on the page are not the high resolution images, they are resized as the full res versions are over 20MB. If you take the image, you'll be taken to a download page where you can get the full res version.
SARLink is a passive satellite backscatter communication system that uses existing spaceborne synthetic aperture radar (SAR) imaging satellites to provide connectivity in remote regions .. As the first technique for passively sending information bits from the ground to a SAR satellite — and with some SAR systems offering open-access data — this system could enable anyone to send information without expensive licenses or subscriptions.
Thus, it provides an accessible way of sending messages in areas without connectivity or in censored environments where active radio transmissions cannot be used. Furthermore, SARLink requires no modification of the satellite infrastructure.. We demonstrate our system using the European Space Agency (ESA) satellite Sentinel-1A, as the data is freely available and the system regularly images all the land on Earth .. a 5.5 ft by 5.5 ft modulating corner reflector could send 60 bits every satellite pass, enough to support low bandwidth sensor data and messages.
I wonder if China has a constellation of similar satellites with the primary function to track the US CVBGs and provide aiming info for their "carrier killer" systems.
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[ 3.8 ms ] story [ 41.4 ms ] threadCheck out this video they made if you want your mind blown: https://www.youtube.com/watch?v=rXCBFlIpvfQ
> Radar instruments can image Earth’s surface through clouds, precipitation, regardless of sunlight, making them particularly well suited for monitoring polar regions. The Sentinel-1C and -1D satellites also carry an Automatic Identification System (AIS) instrument – improving the mission capacity to detect ships and sea pollution. The Sentinel-1D AIS was also activated as the satellite passed over Antarctica capturing the presence of ships in these extreme areas.
We had zoomable, downloadable images in the 90s, with bandwidth as the only constraint.
Now I've got 50x as many pixels and I'm forced to use a bookmarklet and 2 menus to be able to see it larger than my fingernail.
Copernicus browser claims 10x10 meter pixels (which seems to be correct) but the actual resolution of the radar is supposed to be 5m-x-20m for the standard IW mode. I assume "high resolution" here means the data should have 5m x 5m resolution (Strip Map mode) which in Copernicus browser claims 3.5x3.5m pixels.
https://dataspace.copernicus.eu/browser/