That's a really nice write up and the SDR looks quite nice for the price.
It brings back memories one of the things that made radio waves feel "real" to me was a similar setup where we raised and lowered the antenna parallel to the ground and saw the reflections strengthen the received signal or make it nearly vanish.
niwtsol 1 days ago [-]
Pictures of earth from space will never lose their luster for me. I wish money spent on missiles and bombs could be redirected for rockets to launch satellites for scientific purposes.
bajard 1 days ago [-]
Why do most (almost all) images of Earth have Africa in front? Are they stock photos? Is it because only the Sahara Desert is frequently visible?
xandrius 1 days ago [-]
Dunno, maybe the person/team are from Europe? Or maybe if you center it on Asia or the Americas you get a side full of just ocean?
jlhawn 1 days ago [-]
This image is from a geostationary weather satellite operated primarily to monitor weather over Europe. Geostationary satellites must orbit directly above the equator at 0 degrees latitude. Because Europe and Africa share roughly the same longitudes, a geostationary satellite over Europe's longitudes places it directly over the African continent. If an orbit were inclined to center over higher latitudes like Europe, the satellite would trace a figure-eight pattern relative to the ground (called a geosynchronous orbit rather than a geostationary orbit). You are also correct about the Sahara the descending air in that subtropical high-pressure zone suppresses cloud formation, making North Africa one of the most consistently clear and recognizable land features in view from orbit.
also, perhaps the most famous image of Earth from space is "The Blue Marble" [1] taken from Apollo 17 on its way to the moon. It just happened to be located over Africa as its altitude above Earth was ideal for taking a high-res full-disk photograph. Many of the other early full-color photos of the Earth from space [2] also feature South America and the Amazon which is located near the equator. These places are going to be well-lit by the sun no matter what time of the year.
This is the right answer. It's a European GEO satellite that's approaching its assigned longitude of 9.5° East (~ Germany). This is more or less the only viewpoint of Earth it will *ever* have; that's how geosync works.
NOAA decommissioned it's last LRPT/APT capable satillites.
Russia has a couple open access 137MHz sats available Meteor M2-3 and M2-4 I believe they have become flakey with age, damage and other issues.
Those you could stand in your garden with a simple vdipole antenna and a cheap SDR to capture images.
https://gdamdam.github.io/meteor-satellite-reception/meteor-...
It brings back memories one of the things that made radio waves feel "real" to me was a similar setup where we raised and lowered the antenna parallel to the ground and saw the reflections strengthen the received signal or make it nearly vanish.
also, perhaps the most famous image of Earth from space is "The Blue Marble" [1] taken from Apollo 17 on its way to the moon. It just happened to be located over Africa as its altitude above Earth was ideal for taking a high-res full-disk photograph. Many of the other early full-color photos of the Earth from space [2] also feature South America and the Amazon which is located near the equator. These places are going to be well-lit by the sun no matter what time of the year.
[1] https://en.wikipedia.org/wiki/The_Blue_Marble [2] https://en.wikipedia.org/wiki/Timeline_of_first_images_of_Ea...
https://www.esa.int/articles/about-us/directorates/earth-obs...
https://en.wikipedia.org/wiki/Geosynchronous_orbit
Here's a table of (I think?) all of the GEO weather satellites and their positions,
https://space.oscar.wmo.int/satellitestatuses/status
(If you follow up on any of these, you can find real-time views of the Earth from different vantage points).