All Our Eggs in the Landsat Data Continuity Mission
Now that Landsat 5 is out of commission indefinitely, the upcoming launch of the Landsat Data Continuity Mission (LDCM) in December 2012 becomes more important than ever. LDCM is a collaboration between NASA and the U.S. Geological Survey, with the goal of continuing the currently 39-year long collection of moderate resolution remotely sensed imagery. It’s important to ensure that this record continue into the future, so that we can effectively study the unprecedented changes in land cover and land use that have occurred in the past and continue to accelerate in the present.
The LDCM satellite will carry two scientific instruments. The Operational Land Imagery (OLI) will coordinate well with historic Landsat data, with bands similar to the Landsat TM and ETM+ bands 1 to 5 and 7, as well as a panchromatic band. Its spatial resolution will also be similar to previous Landsat systems, with 30 m pixels (15 m for the panchromatic band). It will also include a new band at shorter wavelengths, intended to provide optimal observation in coastal zones, and a new band around 1400 nm, intended to detect cirrus clouds.
The LDCM satellite will also carry the Thermal InfraRed Sensor (TIRS), to continue the collection of thermal imagery that was previously stored in the Landsat TM and ETM+ band 6. It will collect thermal data in two narrow spectral bands, whereas heritage Landsat systems collected only one broad thermal band. This 2-band thermal imagery will have a spatial resolution of 100 m, compared to 60 m for heritage Landsat thermal data. The TIRS data will be registered to the OLI data.
LDCM is designed to return 400 scenes per day to the USGS data archive. This is 150 more scenes per day than Landsat 7. The increase in frequency of coverage should increasing the probability of capturing cloud-free scenes.