User:Steve Quinn/Landsat Data Continuity Mission (LDCM)
The Landsat Data Continuity Mission (LDCM) is the future of Landsat satellites. It will continue to obtain valuable data and imagery to be used in agriculture, education, business, science, and government.
The Landsat Program provides repetitive acquisition of high resolution multispectral data of the Earth's surface on a global basis. The data from the Landsat spacecraft constitute the longest record of the Earth's continental surfaces as seen from space. It is a record unmatched in quality, detail, coverage, and value. [1]
- Landsat Data Continuity Mission
- Phase: Development
- Launch Date: February 2013
- Mission Project Home Page - http://ldcm.nasa.gov/
- Program(s):Earth Systematic Missions
Projected[edit]
The Landsat Data Continuity Mission (LDCM), Landsat 8, launched on February 11, 2013, is the eighth in the series of Landsat satellites. Since 1972, Landsat satellites have been observing and measuring Earth's continental and coastal landscapes at a scale where human impacts and natural changes can be monitored, differentiated, and characterized over time.
These data are archived, preserved and distributed by the Department of Interior U.S. Geological Survey (USGS) and constitute the longest continuous record of the global land surface as seen from space. Landsat data are critically important for understanding and managing forests, farms, changes in urban landscapes, responding to wildfire, measuring the extent of flood and storm damage, examining wildlife habitat, measuring glacial retreat, mapping the extent of the Antarctic ice sheet, and much more. Landsat data have become a part of our nation’s infrastructure, and the data record constitutes a priceless archive that is open and freely available to all people globally.
NASA and the USGS worked together to develop LDCM/Landsat 8. NASA was responsible for building and launching the satellite and its sensors and USGS led the development of the ground system. On May 30, 2013, USGS assumed responsibility for satellite operations and for collecting, archiving and distributing data and the spacecraft name was officially changed from the Landsat Data Continuity Mission (LDCM) to Landsat 8.
Scientific objective[edit]
The scientific objective of Landsat 8 is to collect data sufficiently consistent with data from the earlier Landsat missions to permit studies of land cover and land use change over multi-decadal periods. Consistency in acquisition geometry, calibration, coverage characteristics, spectral and spatial characteristics, output product quality, and data availability have made it possible for people to compare Landsat data from month to month and year to year, and Landsat 8 will continue this tradition by collecting multispectral digital image data providing seasonal coverage of the global land mass.
The Landsat 8 satellite observatory consists of a spacecraft in low-Earth orbit, carrying two-sensors. One sensor, the Operational Land Imager (OLI), collects image data for nine shortwave spectral bands over a 185 km swath with a 30 m spatial resolution for all bands, except a 15 m panchromatic band. The other sensor, the Thermal Infrared Sensor (TIRS), collects image data for two thermal bands with a 100 m resolution over a 185 km swath.
The Landsat 8 ground system sends daily commands to the observatory to schedule the coincident collection of OLI and TIRS data, and the transmission of the sensor data to a network of ground receiving stations. This network includes stations operated under the sponsorship of foreign governments. United States-operated stations forward the data on to the USGS Earth Resources Observation and Science (EROS) Center for processing, archiving, and distribution as part of the Landsat data archive. EROS distributes a standard data product that includes the data for all 11 spectral bands, both the OLI and TIRS bands, radiometrically corrected and co-registered to the UTM cartographic projection including correction for terrain effects. As with all of the Landsat data, EROS distributes digital Landsat 8 data products over the internet to the general public on request and at no cost to requestors.
The Landsat 8 mission extends the more than 40-year Landsat data archive with images sufficiently consistent with data from the earlier missions to allow long-term studies of regional and global land cover change. [2]
How will the Earth system change in the future?[edit]
As the world consumes ever more fossil fuel energy, greenhouse gas concentrations will continue to rise and Earth's average temperature will rise with them. The Intergovernmental Panel on Climate Change (or IPCC) estimates that Earth's average surface temperature could rise between 2°C and 6°C by the end of the 21st century.
For most places, global warming will result in more hot days and fewer cool days, with the greatest warming happening over land. Longer, more intense heat waves will happen more often. High latitudes and generally wet places will tend to receive more rainfall, while tropical regions and generally dry places will probably receive less rain. Increases in rainfall will come in the form of bigger, wetter storms, rather than in the form of more rainy days. In between those larger storms will be longer periods of light or no rain, so the frequency and severity of drought will increase. Hurricanes will likely increase in intensity due to warmer ocean surface temperatures. So one of the most obvious impacts of global warming will be changes in both average and extreme temperature and precipitation events.
Scientists are also monitoring the great ice sheets on Greenland and West Antarctica, both of which are experiencing increasing melting trends as surface temperatures are rising faster in those parts of the world than anywhere else. Each of those ice sheets contains enough water to raise sea level by 5 meters and if our world continues to warm at the rate it is today then it is a question of when, not if, those ice sheets will collapse. Some scientists warn we could lose either, or both, of them as soon as the year 2100.
Ecosystems will shift as those plants and animals that adapt the quickest will move into new areas to compete with the currently established species. Those species that cannot adapt quickly enough will face extinction. Scientists note with increasing concern the 21st century could see one of the greatest periods of mass extinction of species in Earth's entire history. Ultimately, global warming will impact life on Earth in many ways. But the extent of the change is up to us. [3]
See: Related missions (http://science.nasa.gov/earth-science/big-questions/how-well-can-we-predict-future-changes-in-the-earth-system/)
How is the global earth system changing?[edit]
Earth is currently in a period of warming. Over the last century, Earth's average temperature rose about 1.1°F (0.6°C). In the last two decades, the rate of our world's warming accelerated and scientists predict that the globe will continue to warm over the course of the 21st century. Is this warming trend a reason for concern? After all, our world has witnessed extreme warm periods before, such as during the time of the dinosaurs. Earth has also seen numerous ice ages on roughly 11,000-year cycles for at least the last million years. So, change is perhaps the only constant in Earth's 4.5-billion-year history.
Scientists note that there are two new and different twists to today's changing climate: (1) The globe is warming at a faster rate than it ever has before; and (2) Humans are the main reason Earth is warming. Since the industrial revolution, which began in the mid-1800s, humans have attained the magnitude of a geological force in terms of our ability change Earth's environment and impact its climate system.
Since 1900, human population doubled and then double again. Today more than 6.5 billion people inhabit our world. By burning increasing amounts of coal and oil, we drove up carbon dioxide levels in the atmosphere by 30 percent. Carbon dioxide is a "greenhouse gas" that traps warmth near the surface.
Humans are also affecting Earth's climate system in other ways. For example, we transformed roughly 40 percent of Earth's habitable land surface to make way for our crop fields, cities, roads, livestock pastures, etc. We also released particulate pollution (called "aerosols") into the atmosphere. Changing the surface and introducing aerosols into the atmosphere can both increase and reduce cloud cover. Thus, in addition to driving up average global temperature, humans are also influencing rainfall and drought patterns around the world. While scientists have solid evidence of such human influence, more data and research are needed to better understand and quantify our impact on our world's climate system[4]
References and notes[edit]
- All material is in the public domain from NASA.gov