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Europe's first geostationary sounder satellite is launched

(www.eumetsat.int)
201 points diggan | 1 comments | 05 Jul 25 14:21 UTC | HN request time: 0s | source
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abra0 ◴[05 Jul 25 18:46 UTC] No.44474667[source]▶
> MTG-S1 is the first geostationary meteorological sounder satellite to fly over Europe

I was confused for a minute on how it's both _geostationary_ and _over Europe_ -- you can't be geostationary if your orbit is not over the equator!

Turns out[1] the MTG-S1 satellite is in fact geostationary and parked at exactly 0°00'00"N 0°00'00"E (off the coast of Ghana), 42164 km up from the center of Earth, it's just pointing at Europe at an angle.

1 - https://space.oscar.wmo.int/satellites/view/mtg_s1

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thmsths ◴[05 Jul 25 20:13 UTC] No.44475193[source]▶
I am surprised they would pick 0 for the latitude, it seems that most of Europe, whether it's the land or the people is east of that. Maybe some important weather systems develop over the Atlantic and they want to track that?
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1. labster ◴[06 Jul 25 00:14 UTC] No.44476617[source]▶
It’s exactly that. In fact, information propagates along with the winds. If you don’t observe upstream, you instead propagate an information hole. Each new model run incorporates the output of the previous run to preserve sparse weather information. It’s not that there are few observations, it’s that Earth is really big.