In today’s world, it takes less time to download a country’s Digital Elevation Model (DEM) than to sign up for Gmail. SRTM and ASTER GDEM have served the world for quite a while. And high resoultion DEMs in the order of a meter are free to obtain in countries like the United States. And here is where the news is ! The National Elevation Dataset or most commonly called as NED are going to be soon replaced with much higher resolution 3DEP!
So what is it all about? 3DEP or the 3D Elevation Program is an intiative to develop very high resoultion DEMs using LiDAR for the entire conterminous United States, Hawaii and the US territories. Yes, for the entire country at a very very high resolution! There are several beneficial areas including production of FEMA’s flood maps and natural disaster application areas by United States.
Wait, did they leave Alaska out? Actually, no. Due to high cloud cover and inaccessible areas, the project will develop a high resolution DEM with RADAR interferometery (InSAR)!
3DEP – Quality Data by Collection Year, USA
Source: USGS. A lidar DEM of Mount St.Helen in Washington, USA.
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The International Space Station is a picture of serenity; floating like a boat on a scenic and calm sea of emptiness. A personification of beauty in outer space. Remember the visuals of the ISS from GRAVITY! Looks like NASA fell in love with the view of earth from outer space so much that their latest experiment “High Definition Earth Viewing” is all about this. 
NASA has placed 4 commercial HD video cameras (from Hitachi, Panasonic, Sony and Toshiba) on the exterior of the ISS. The HD video cameras mounted on the External Payload Facility of ESA’s Columbus module were activated April 30, 2014. The cameras are enclosed in a pressurized and temperature controlled housing, video from these cameras is transmitted back to the ground station and is streamed live for everyone! ISS HD Earth Viewing Experiment is for everyone to witness 🙂 Here’s what I was able to see at 14.34 Central European Time, 10th May, 2014.
The primary objective of the experiment is to analyze the effect of space environment (radiation effects, etc) on the quality of video cameras which will then help NASA engineers to decide on the best type of camera to utilize on future missions.
The ISS orbits around Earth once every 90 minutes and witnesses a sunrise/sunset about every 45 minutes. So if the video appears to be black then it means that the ISS is in darkness. If there is a technical issue with the video stream, the video will appear gray.
NASA operates one camera at a time and switches between the 4 cameras. The forward looking camera is powered first, followed by the camera that looks directly below the ISS onto Earth and then each aft looking camera. To learn more about NASA’s ISS HD Earth Viewing Experiment, visit here. This link shows the current position of the ISS.
ISS HD Earth Viewing Experiment: Thank you NASA for providing us the chance to look at the blissful emptiness of space 🙂 Here’s the link to the LIVE video streaming.
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