The Landsat legacy continues…

By John Duncan (@FoodSecIPG) and Ellie Biggs (@EllieMBiggs)

On February 11th the longest Earth Observation (EO) mission will be extended with the launch of the Landsat Data Continuity Mission (LDCM) satellite on board the Atlas V rocket at the Vandenberg Air Force Base, California. Imaging of the Earth using Landsat satellites began in 1972, with Landsat 1 (originally named the Earth Resources Technology Satellite) and has been continued through the launch of six subsequent satellites prior to the LCDM (Landsat 6 failed to achieve orbit). Landsat EO data featured in nearly 200 presentations at the AGU fall meeting in 2012 indicating its continuing importance and impact to science. It contributes to a range of scientific research and applied commercial applications spanning agriculture, ecology, water resources, natural hazards, deforestation, spread of disease, web-mapping and even hunting Osama Bin Laden.

Aside to scientific analysis, Landsat data has led to discovery of new lands, features and species on the earth’s surface. A reef in the Indian Ocean and an island off the coast of Labrador, Canada, named Landsat Island have been discovered using Landsat data. In verifying the existence of Landsat Island, a polar bear swung a paw at a scientist from the Canadian Hydrographic Service as he was lowered from a helicopter onto the island. Scientists found regions of medium altitude forest in pristine condition on Mount Mabu, Mozambique; unmarked on maps and known only to indigenous peoples using Landsat images. These forests turned out to be biodiversity hotspots and led to discovery of new species of flora and fauna, including a new species of adder and butterflies.

The use of Landsat imagery in conjunction with other environmental data in land use management has been shown to deliver real economic benefits. The use of Landsat data in Iowa to inform decision-making which balances the needs of fertilizer applications to enhance crop production whilst not contaminating groundwater and thus potable water stores created benefits of $858 million per year compared to what could be achieved without EO data. This study, limited to a small region in Iowa, showed the integration of Landsat data into decision making across the spatial extent of the US or the globe would yield huge financial gains. The potential for realising these financial benefits is enhanced through the freely available nature of Landsat imagery and the technological advances* on board the LDCM.

The data provided from the LCDM will lead to further discoveries across a range of disciplines and be vital to analysing the spatio-temporal dynamics of global to local change. The benefits of Landsat data to studying temporal change on the Earth’s surface were enhanced by the Landsat archive being made freely available in 2008, allowing multiple images of the same location to be obtained free of charge. Thus the LCDM will contribute to topical current research and important land use management decisions, which will have subsequent impacts on society as the importance of moving the earth towards a sustainable future is more apparent. LCDM data will have an input into ensuring a future of mitigating the impacts of, and adapting to, climate change and maximizing our use of environmental resources without degradation, but no longer hunting for the head of Al-Qaeda.

GECEO Researchers Interested in learning more…

Why not do a Masters degree in Applied GIS and Remote Sensing or Geoinformation Science and EO for Environmental Modelling and Management and join Geography and Environment’s vibrant Global Environmental Change and Earth Observation (GECEO) research theme at the University of Southampton.

*The technical bit…

Through the succession of Landsat satellites it is possible to track the technological advances in sensor technology. Landsat 1,2 and 3 carried the Return Beam Vidicon sensor (RBV) providing photographic images of the earth’s surface and Multispectral Scanner sensor (MSS) providing radiometric measures in four spectral bands. The Thematic Mapper (TM) sensor was carried on board Landsat 4,5,(6) and 7 with seven spectral bands and improved spatial resolution. The Enhanced Thematic Mapper (ETM+) sensor is carried on board Landsat 7 and includes sensing in a 15m panchromatic band in addition to the spectral bands of the TM sensor. The LCDM will carry two sensors providing measurements in 11 spectral bands enabling data to be used in conjunction with the archive of Landsat imagery and also expanding the quality, and range of scientific applications for which data can be used. The Operational Land Imager (OLI) will provide measurements in nine spectral bands providing consistency with previous missions with an additional blue band to aid sensing of ocean colour and coastal areas and a shortwave infrared band to detect cirrus clouds. The Thermal Infrared Sensor (TIRS) uses quantam well infrared photodetectors to sense in two thermal infrared bands, crucial to managing water resources and analyzing water use.

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