As football fans worldwide keep their eyes trained on Brazil, ESA’s Proba-V minisatellite captures the entire country in a single image.
The Andean Plateau, or Altiplano, of neighboring Bolivia, including Lake Titicaca and the giant Salar Uyuni salt flat, are visible towards the scene’s western edge.
Proba is smaller than a cubic meter but its view spans a mighty 2250 km. It reveals details 300 m across but the central part of the image is sharper – down to 100 m – as demonstrated in the right-hand image, which shows a detail of the River Negro joining the mighty River Amazon.
Proba-V is a miniaturized ESA satellite tasked with a full-scale mission: to map land cover and vegetation growth across the entire planet every two days.
The camera’s continent-spanning field of view collects light in the blue, red, near-infrared and mid-infrared wavebands, ideal for monitoring plant and forest growth as well as inland water bodies.
Proba’s images are processed and distributed to hundreds of scientific end users by VITO, Belgium’s Flemish Institute for Technological Research, extending the coverage of previous generations of the Vegetation camera flown on the Spot-4 and Spot-5 satellites.
Image credit: ESA/BELSPO
This radar image is one of the first from the Sentinel-1A satellite, acquired on 20 April – less than three weeks after its launch on 3 April.
The image shows the Salar de Uyuni in Bolivia, which is the largest salt flat in the world.
Occupying over 10,000 sq km, the vast Salar de Uyuni lies at the southern end of the Altiplano, a high plain of inland drainage in the central Andes. Some 40,000 years ago, this area was part of a giant prehistoric lake that dried out, leaving behind the salt flat.
While the salt flat appears an almost homogenous white in optical satellite imagery, here we see it in shades of grey, and it looks almost like a lake. This has to do with how the radar signal reacts to different surfaces: areas where the radar signal is absorbed appear darker, while areas where the signal is reflected back to the satellite appear lighter. This gives Earth observation experts an indication of how rough or smooth the surfaces area, differences in salt density or even the presence of water.
But on the whole, the Salar de Uyuni is very flat, with a surface elevation variation of less than 1 m. This makes the area ideal for calibrating satellite radar altimeters – a different kind of radar instrument that measures surface topography. The future Sentinel-3 mission will carry a radar altimeter.
The surrounding terrain is rough in comparison to the vast salt flat and is dominated by the volcanoes of the Andes mountains forming part of the Pacific Ring of Fire.
Sentinel-1A is the first in the two-satellite Sentinel-1 mission for Europe’s Copernicus program. Its radar data will be used for a variety of applications, including the surveillance of the marine environment, monitoring land-surface for motion risks, mapping for forest, water and soil management, and mapping to support humanitarian aid and crisis situations.
This image is featured on the Earth from Space video program.
Image credit: ESA
This ALOS image was acquired over Anatolia’s dry, central plateau in Turkey. On the left side we can see the whole of Lake Tersakan, with part of Lake Tuz in the upper right corner.
Lake Tuz is Turkey’s second largest lake, as well as one of the largest saline lakes in the world. During the summer months, however, the lake water recedes to expose a thick layer of salt.
The bright white surface during these dry summer months has been used by Earth-observing satellites to calibrate their sensors for the color white – much like how you would adjust a camera’s white balance setting.
Japan’s Advanced Land Observing Satellite (ALOS) captured this image on 21 October 2010 with its Advanced Visible and Near Infrared Radiometer type-2 instrument.
This image is featured on the Earth from Space video program.
Photo credit: JAXA, ESA
Korea’s Kompsat-2 satellite captured this image over the sand seas of the Namib Desert on 7 January 2012. The blue and white area is the dry river bed of the Tsauchab. Black dots of vegetation are concentrated close to the river’s main route, while salt deposits appear bright white. Running through the river valley, a road connects Sossusvlei to the Sesriem settlement. At the road’s 45th kilometer, seen at the lower-central part of the image, a white path shoots off and ends at a circular parking area at the base of a dune. This is Dune 45, a popular tourist stop on the way to and from Sossusvlei. In this image, there appears to be some shadow on the western side. From this we can deduce that the image was acquired during the late morning.
ESA supports Kompsat as a Third Party Mission, meaning it uses its ground infrastructure and expertise to acquire, process and distribute data to users.
This image is featured on the Earth from Space video program.
Photo credit: KARI/ESA
