12
votes
Accepted
What is the large circular device with a dozen concentric circles on Sentinel 3B?
It appears to match the "X band antenna" on this diagram: (Taken from https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/copernicus-sentinel-3 -- But they credit ESA for that ...
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9
votes
What is the large circular device with a dozen concentric circles on Sentinel 3B?
After reading @ Saiboogu's answer explaining what this is, I found some additional helpful information.
This is an isoflux antenna, designed to provide an approximately constant flux of broadcast ...
- 149k
6
votes
Accepted
Sentinel-2C and frequency of acquisition
Yes, 2c replaces a, d replaces b
The mission is based on a constellation of two identical satellites in the same orbit, 180° apart for optimal coverage and data delivery. So, when Sentinel-2A retires,...
- 12.4k
4
votes
Accepted
Why is Sentinel 3B's dish antenna overwrapped with metallized film?
Almost any time you see a satellite, you see those shiny covers. Those are almost always thermal blankets, and a good deal of the time they are blankets known as MLI (Multi-Layer Insulation). MLI ...
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3
votes
Accepted
How will the corner cube retroreflector array be used on Sentinel 3B?
That is definitely the Laser Retro Reflector (LRR). They are used to provide very precise ranging information. The Sentinel 3 LRR is a hemisphere of 7 corner cube reflectors on the Earth-facing side ...
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3
votes
Why is Sentinel 3B's dish antenna overwrapped with metallized film?
@Dave's excellent answer has solved the mystery for me. It's germanium! Not a metal exactly, but a semiconductor.
(a bit of) The Physics:
Metals have a high density of free carriers that can be ...
- 149k
3
votes
Time of satellite passing overhead
I think the step that has caused you problems is "Since the sun angle varies from day-to-day, this also means that the clock time that the satellites pass overhead will shift from day-to-day.&...
- 9,774
3
votes
What is the parameter which stays constant at a location for downloading from Sentinel Copernicus Data?
If I understand your question correctly, you might be able to use the location search query option in the API to get content for a particular rectangle specified by the latitude and longitude of the ...
- 586
2
votes
Accepted
What are the details required to automate the download of Data products of Sentinel - 1 from Copernicus SciHub?
You may want to use Sentinelsat, which is an open source Python library to support searching, downloading and retrieving the metadata of Sentinel satellite images from the Copernicus Open Access Hub.
...
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1
vote
Accepted
Why can Cryosat's dual antenna "better discern steep slopes" of Antarctic ice than Sentinel-3?
The SIRAL instrument has better spatial resolution due to its waveform processing:
Unlike conventional radar altimeters, where the interval between
pulses is about 500 us, the CryoSat-2 altimeter ...
- 12.8k
1
vote
How will the "fleet of small asteroid hunters" proposed by the B612 Foundation & York Space Systems work?
In theory, a smaller telescope can see a dim object by just looking longer than a larger one. There are issues of noise and stability that limit this, but for small factors it works.
So their plan ...
- 12.8k
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