The Landsat Data Continuity Mission (LDCM), a collaboration between NASA and the U.S. Geological Survey, will provide moderate-resolution (15 m–100 m, depending on spectral frequency) measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave infrared, and thermal infrared. LDCM will provide continuity with the 38-year long Landsat land imaging data set. In addition to widespread routine use for land use planning and monitoring on regional to local scales, support of disaster response and evaluations, and water use monitoring, LDCM measurements directly serve NASA research in the focus areas of climate, carbon cycle, ecosystems, water cycle, biogeochemistry, and Earth surface/interior.
Unprecedented changes in land cover and use are having profound consequences for weather and climate change, ecosystem function and services, carbon cycling and sequestration, resource management, the national and global economy, human health, and society. The Landsat data series, begun in 1972, is the longest continuous record of changes in Earth's surface as seen from space and the only satellite system designed and operated to repeatedly observe the global land surface at moderate resolution. Freely available Landsat data provide a unique resource for people who work in agriculture, geology, forestry, regional planning, education, mapping, and global change research.
The LDCM satellite payload consists of two science instruments—the Operational Land Imager (OLI) and the Thermal InfraRed Sensor (TIRS). These two sensors will provide seasonal coverage of the global landmass at a spatial resolution of 30 meters (visible, NIR, SWIR); 100 meters (thermal); and 15 meters (panchromatic). The spectral coverage and radiometric performance (accuracy, dynamic range, and precision) are designed to detect and characterize multi-decadal land cover change in concert with historic Landsat data. Coordinated calibration efforts of USGS and NASA will again be part of the LDCM calibration strategy. The LDCM scene size will be 185-km-cross-track-by-180-km-along-track. The nominal spacecraft altitude will be 705 km. Cartographic accuracy of 12 m or better (including compensation for terrain effects) is required of LDCM data products. LDCM includes evolutionary advances in technology and performance. The OLI provides two new spectral bands, one tailored especially for detecting cirrus clouds and the other for coastal zone observations, and the TIRS will collect data for two more narrow spectral bands in the thermal region formerly covered by one wide spectral band on Landsats 4–7. Additionally, LDCM is required to return 400 scenes per day to the USGS data archive (150 more than Landsat 7), increasing the probability of capturing cloud-free scenes for the global landmass.
LDCM is made possible by a partnership between NASA and USGS that builds upon a strong relationship developed during previous Landsat missions. NASA's expertise in Earth observation missions and USGS's expertise in data archives and remote sensing data processing provides for a mutually beneficial partnership.
NASA's LDCM responsibilities include development of the OLI and TIRS instruments, spacecraft, launch vehicle, implementation of the USGS-funded Mission Operations Element, and mission on-orbit verification. NASA is acquiring most elements of the LDCM space segment from industry with Goddard Space Flight Center (GSFC) acting as the mission integrator and leading mission systems engineering. TIRS is being built in-house at GSFC and launch services are provided by Kennedy Space Center. The LDCM mission operations center will be at GSFC.
USGS is providing the ground data processing systems which will be located at the USGS Earth Resources Observation and Science (EROS) center. USGS is acquiring the ground data processing systems from industry. The flight operations team is also provided by USGS through an existing NASA contract. USGS funds and leads the Landsat science team. Upon completion of on-orbit verification, USGS will lead post-launch calibration activities, satellite operations, data product generation, and data archiving.
The Operational Land Imager (OLI) is being built by the Ball Aerospace and Technologies Corporation. The Ball contract was awarded in July 2007. OLI improves on past Landsat sensors using a technical approach demonstrated by a sensor flown on NASA's experimental EO-1 satellite. OLI is a push-broom sensor with a four-mirror telescope and 12-bit quantization. OLI will collect data for visible, near infrared, and short wave infrared spectral bands as well as a panchromatic band. It has a five-year design life. The graphic below compares the OLI spectral bands to Landsat 7's ETM+ bands.
The OLI will collect data for two new bands, a coastal band and a cirrus band, as well as the heritage Landsat multispectral bands. Additionally, the bandwidth has been refined for six of the heritage bands. Graphic created by L.Rocchio & J.Barsi.
The Thermal InfraRed Sensor (TIRS) was added to the LDCM payload to continue thermal imaging and to support emerging applications such as evapotranspiration rate measurements for water management. TIRS is being built by NASA GSFC and it has a three-year design life. The 100 m TIRS data will be registered to the OLI data to create radiometrically, geometrically, and terrain-corrected 12-bit LDCM data products.
The LDCM spacecraft is being built by Orbital Sciences Corporation. The spacecraft contract was awarded in April 2008. The LDCM spacecraft will accommodate two government furnished instruments forming the LDCM Observatory, OLI and TIRS. The spacecraft has a design life of 5 years, but carries sufficient fuel for 10 years of operations. The spacecraft provides the capability for imaging (both nadir and off-nadir), calibration, and orbit maintenance maneuvers. A command and data handling subsystem provides the band ordering and data compression necessary to meet the total data rate and data volume requirements. The spacecraft communications subsystem provides the ability to transmit mission data to multiple sites concurrently in order to support Landsat International Cooperators.
An Atlas-V rocket
Launch services are provided by the NASA Kennedy Space Center (KSC). The launch vehicle will be an Atlas-V rocket and is managed by KSC and procured from United Launch Alliance.
The LDCM Ground System includes all of the ground-based assets needed to operate the LDCM observatory. The primary components of the Ground System are the Mission Operations Element, Collection Activity Planning Element, Ground Network Element, and the Data Processing and Archive System.
The Missions Operations Element (MOE) is being provided by the Hammer Corporation. The MOE contract was awarded in September 2008. The MOE provides capability for command and control, mission planning and scheduling, long-term trending and analysis, and flight dynamics analysis. The overall activity planning for the mission is divided between the MOE and Collection Activity Planning Element (CAPE). The CAPE schedules activities on a path-row scene basis. The MOE converts CAPE-generated path-row scenes to observatory activities, schedules these and any other detailed observatory activities, and generates commands necessary to collect the identified scenes and operate the observatory. The Ground Network Element (GNE) is comprised of two nodes located at Fairbanks, Alaska and Sioux Falls, SD. Each node in the GNE includes a ground station that will be capable of receiving LDCM X-band data. Additionally, each station provides complete S-band uplink and downlink capabilities. The Data Processing and Archive System (DPAS) includes those functions related to ingesting, archiving, calibration, processing, and distribution of LDCM data and data products. It also includes the portal to the user community. The Ground System, other than the MOE, is developed by USGS largely through their support service contract.
LDCM is now in the final phase of design and fabrication. Due to the high national importance of the mission and the need to maintain the continuity of the Landsat data record, NASA and USGS will strive to launch LDCM in December 2012.