Landsat 9 image of Detroit, Michigan, and Windsor, Ontario, acquired on Oct. 31, 2021. Plumes of sediment are clearly visible in both Lake Erie and Lake St. Clair. Image credit: NASA/USGS
A set of six fantastic first light images from Landsat-9 were released by NASA and the U.S. Geological Survey (USGS) last week. All acquired on the 31st October 2021, the images include Detroit & Michigan with Lake Erie as shown on the left; the intersection of cities and beaches along the Florida panhandle coastline; Navajo Country in Arizona; mountains of the Himalayas as shown below; and shorelines of northwest Australia; together with a composite image showcasing the different sensors on board.
Landsat-9 which was launched on the 27th September 2021 and replaces the existing Landsat-7 satellite, and these first light images being the initial opportunity for scientists to see what the new satellite can do. The data is transmitted to Earth with higher radiometric resolution than Landsat-7 meaning it can detect more minute differences in colour of the planet; for example, Landsat 9 can differentiate more than 16,000 shades of a given wavelength colour; Landsat 7 can only differentiate 256 shades.
Landsat 9 carries two instruments: the Operational Land Imager 2 (OLI-2), which detects visible, near-infrared and shortwave-infrared light in nine wavelengths, and the Thermal Infrared Sensor 2 (TIRS-2), which detects thermal radiation in two wavelengths to measure Earth’s surface temperatures.
The satellite is currently undergoing its 100-day system and instrument testing and calibration, and assuming it is successful the satellite will be handed to USGS in January. At which point, along with the existing Landsat-8, these two satellites will be able to collect one and half thousand images of the planet each day, and will image the entire globe every eight days. Landsat-9 data will made freely available in early 2022.
Landsat 9 image acquired on Oct. 31, 2021 shows city of Kathmandu, Nepal, in the bottom left, with glaciers, and the lakes formed by glacial meltwater, visible in the top middle. Image credit: NASA/USGS
It was also announced last Friday that the US Vice President Kamala Harris will host the Biden administration’s first meeting of the National Space Council on 1st December, where she will present Landsat-9’s first light images.
Whilst celebrating the first achievements of Landsat-9, NASA is not standing still and is already looking to the next Landsat mission. Last week they issued a request for information to identify potential imaging sensor technology for future Earth Observation (EO) satellites under the Landsat program.
Another country who never stands still in the EO world is China, and last week they launched their latest satellite. The SDGSAT-1 is focused around the United Nation’s 2030 Agenda of Sustainable Development, and aims to fill the data gaps and improve the monitoring of the 17 Sustainable Development Goals and their underlying targets.
Launched from the Taiyuan Space Center last Thursday the satellite was put into a near-circular orbit at an altitude of approximately 315 miles by the Long March 6 rocket.
The satellite was the first EO launch by the Chinese Academy of Sciences (CAS) and was developed by the International Research Center of Big Data for Sustainable Development Goals (CBAS). It carries three instruments: a colour multispectral optical camera, an instrument operating in the thermal bands and a low-light level sensor. These instruments have a swath width of up to 180 miles and cover the globe every 11 days. The collected data is anticipated as supporting the monitoring of energy consumption, human settlement patterns, and coastal environments, and could be made available within six months.
Both of these satellites enhance the abilities of the EO to measure and monitor what is happening in a rapidly changing world.
