Posted on March 4th, 2014

Reaching Orbit – LandSat 8

I’d like to wish a very Happy 1st Birthday to Landsat 8. Queue the balloons, clowns and petting zoo! Unfortunately, Landsat 8 can’t enjoy these party favors as they won’t fair well in space, nobody wants a petting zoo in space. While we celebrate down here, Landsat 8 orbits 440 miles overhead, collecting 550 images per day. As it zooms through it’s one year anniversary in orbit, we take a look at what Landsat 8 has already accomplished and the Landsat mission as a whole.

In our hometown of Boulder, CO, at the University of Colorado, a team of researchers used Landsat 8 in conjunction with other sensors to identify the coldest spots on Earth. The lowest temperature recorded was minus 136 degrees Fahrenheit on the East Antarctic Plateau on the ridge between Dome Fuji and Dome Argus. This discovery was a byproduct of studying cracks in the snow on the ridges, leading the researchers to believe that it was getting cold enough for the top layer of snow to shrink and crack. Another bone chilling fact, the coldest inhabited places on Earth are the towns of Verkhoyansk and Oimekon in northeastern Siberia where temperatures have fallen to minus 90 degrees F twice on record. I feel bad for complaining about the recent polar vortex when I read about those temperatures.

If you’re curious how any place can get so dang cold, check out this nifty video that depicts the conditions necessary to harbor the coldest place on Earth. (Video Credit: NASA’s Goddard Space Flight Center)

When Landsat 8 was preparing to launch I was holding my breath, terrified that the satellite might not make it to orbit, breaking 41 years of continuous Landsat data collection. Until I took my remote sensing courses I didn’t understand why this was so important. Now I know that having datasets that overlap in time between the Landsat sensors is necessary in order to calibrate one to the other.  There will always be differences and improvements in the satellites that will cause the findings to vary between sensors, but being able to identify and take into account these variances allows for a consistent database that spans decades and records changes on Earth and its atmosphere.

forest-cover-globalThe above map depicts global forest cover changes from 2000 to 2012. (Map Credit: NASA Goddard, based on data from Hansen et al., 2013)

A good example of this value is the recent study on global forest losses and gains. The data used in this study was taken from Landsat 7 ranging from 2002 and 2012. This is the first time a consistent method has been used to map forest loss and gain. Thanks to this study, tree cover and density can be compared at the local, country, regional and global levels. Researchers from the University of Maryland analyzed 654,000 Landsat images and 143 billion pixels with help from the Google Cloud and other research bodies.

These maps help researchers better understand the socio-political and environmental impacts on forest, such as: some countries policies to log on the sides of roads; the effect of civil wars on land that was previously protected; the cutting down and replanting of forests in the US; and the destruction of forests due to natural disasters like tornadoes. You can explore their research in Google Earth Engine here.

With Landsat 8, research such as this can continue into the future without interruption, giving us insight and understanding into our changing planet.

Katie Nelson
Geospatial Ninja
(303) 718-7163

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