Landsat Greatest Hits Video
Landsat’s Global Perspective Over 40 Years, NASA
“On July 23rd, 1972, the first Landsat spacecraft launched into orbit. At the time, it was called “Earth Resources Technology Satellite,” or ERTS, and was the first satellite to use a scanning spectrophotometer.
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Celebrating this anniversary, this video is a “greatest hits” montage of Landsat data. Throughout the decades, Landsat satellites have given us a detailed view of the changes to Earth’s land surface.”
Being one who works with Landsat images everyday, I can say with the amount of data, science and beauty offered by these platforms, and the low popularity among the public and politicians, the Landsat program is one of the most under appreciated space program ever. We definitely could use more of these birds.
Why not add scanning multispectral imagers to the ISS? it covers most of the Earth’s surface, and this couldbe done at a small fraction of the cost of a dedicated mission. In fact, proposals have been made too CASIS.
Don’t have an exact answer for you but directly out of my brain I can think of two problems. First is the orbit, Landsat imagery is divided into exact rows and paths and it has a temporal resolution of 16 days. That means the bird comes back to the spot every 16 days. Having identical scene for each temporal snapshot is really helpful for remote sensing exercises, and I’m unsure if the orbit of ISS fits such criteria. Secondly AFIK Landsat imagers are pushbroom sensors that works like a scanner, so it requires quite an undisturbed platform to minimize fuzziness. With the amount of activities onboard ISS I’m not sure if it is “stable” enough for such sensors.
I do think the stability issue can be tackled though, and if so perhaps ISS can also become a remote sensing platform with minimal cost.
Well, that’s just it. A high-speed camera is available (and has been proposed to CASIS) that is designed to function as a multispectral pushbroom and would be suitable for mounting on the truss. The ISS is normally in LVLH attitude and passes over almost every spot on the landsat imagery (well, not Antarctica). Modern GIS methods quantify data by surface location and can easily compensate for variations in viewing angle and imaging intervals. The electronics and optics can be installed, maintained and continuously upgraded at a small fraction of the cost of a free-flyier. Power and datalink are already available. The ball is in your court CASIS!
Here is a really good read on the difficulties Landsat 8 program went through before its up in the sky capturing images : http://www.digital-geograph…
P.S. I am not in anyway related to digital-geography.com