March 22, 2013
First LDCM Satellite Images Released By NASA
redOrbit Staff & Wire Reports - Your Universe Online
NASA officials announced on Thursday the release of the first images taken by the Landsat Data Continuity Mission (LDCM) satellite, which was launched in February.
According to the US space agency, the pictures were taken by LDCM on March 8 at approximately 1:40pm EDT. They depict the intersection of the Great Plains and the Front Range of the Rocky Mountains in Wyoming and Colorado, and were acquired using the satellite´s Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) instruments simultaneously.
“We are very excited about this first collection of simultaneous imagery. These images confirm we have two healthy, functioning sensors that survived the rigors of launch and insertion into Earth orbit,” Jim Irons, LDCM project scientist at the NASA Goddard Space Flight Center (GSFC) in Greenbelt, Maryland, said.
The two images released on Thursday were close-up shots taken using the OLI sensor at its maximum resolution of 15 meters per pixel, NASA officials explained. One of the images was created with reflected red, green and blue light, showing the region as it would appear to the human eye. The other picture was made from blended shortwave infrared, near-infrared, and green wavelengths — wavelengths of light not usually visible to people.
“The first OLI and TIRS images look great right out of the box,” Irons said. “I have waited a long time to view the first LDCM images and I could not be more impressed with their appearance.”
“It's a really great day,” added GSFC instrument scientist Jeff Pedelty, who worked on the OLI. Pedelty said that he was very impressed with the level of detail that can be seen thanks to enhancements made to the instrument. “It's wonderful to see, there's no doubt about it, and it's a relief to know that this is going to work wonderfully in orbit.”
Part of the level of detail captured by not just the OLI but the TIRS as well comes from the push-broom design of both instruments, according to NASA. Rather than scanning back and forth across an area of terrain, push-broom style data collection looks across the entire region at one time, which allows the sensors to observe each section of the ground for a longer period of time.
These images were processed using pre-launch settings, the space agency said. Now that the LDCM is in orbit, those settings must be reviewed and adjusted in order to make sure that the data can accurately measure the intensity of reflected and emitted light received by the OLI and TIRS. Checks for both instruments are planned to take place over the next two months, with OLI using its solar diffuser panel to look indirectly into the sun.
“The two LDCM sensors collect data simultaneously over the same ground path,” NASA explained. “OLI collects light reflected off the surface of Earth in nine different regions of the electromagnetic spectrum, including bands of visible light and near-infrared and short-wave-infrared bands, which are beyond human vision. TIRS collects data at two longer wavelength thermal infrared bands that measure heat emitted from the surface.”
“By looking at different band combinations, scientists can distinguish features on the land surface. These features include forests and how they respond to natural and human-caused disturbances, and the health of agricultural crops and how much water they use,” they added. “Data from LDCM will extend a continuous, 40-year-long data record of Earth's surface from previous Landsat satellites, an unmatched, impartial perspective that allows scientists to study how landscapes all across the world change through time.”
LDCM is expected to undergo checkout and commissioning procedures for the next several weeks before beginning normal operations sometime in May. At that time, NASA said that they will surrender control of the satellite to the US Geological Survey (USGS), which will oversee LDCM operations throughout its scheduled five-year mission. The USGS will collect and process data from both satellite instruments. The information will then be added to the Landsat Data Archive at the USGS Earth Resources Observation and Science Center (EROS). All data uploaded to the online archive will be distributed, free of charge, NASA said.