Landsat program
The images, archived in the United States and at Landsat receiving stations around the world, are a unique resource for global change research and applications in agriculture, cartography, geology, forestry, regional planning, surveillance and education, and can be viewed through the U.S. Geological Survey (USGS) "EarthExplorer" website.
In 1965, William T. Pecora, the then director of the United States Geological Survey, proposed the idea of a remote sensing satellite program to gather facts about the natural resources of our planet.
Pecora stated that the program was "conceived in 1966 largely as a direct result of the demonstrated utility of the Mercury and Gemini orbital photography to Earth resource studies."
So, when Landsat 1 was proposed, it met with intense opposition from the Bureau of Budget and those who argued high-altitude aircraft would be the fiscally responsible choice for Earth remote sensing.
But budgetary constraints and sensor disagreements between application agencies (notably the Department of Agriculture and DOI) again stymied the satellite construction process.
[3] The Hughes Aircraft Company from Santa Barbara Research Center initiated, designed, and fabricated the first three Multispectral Scanners (MSS) in 1969.
[9] The head of the newly formed National Space Council, Vice President Dan Quayle, noted the situation and arranged emergency funding that allowed the program to continue with the data archives intact.
An advantage of Landsat imagery, and remote sensing in general, is that it provides data at a synoptic global level that is impossible to replicate with in situ measurements.
Additionally, the system was designed to ensure a continuous image sweep across a swath equivalent to 185 km on the Earth's surface.
Accessing Landsat's imagery became substantially more expensive, making the French SPOT satellite's images a more cost-effective alternative for many users.
The different spectral bands used on satellites in the Landsat program provide many applications, ranging from ecology to geopolitical matters.
[23] Landsat imagery provides one of the longest uninterrupted time series available from any single remote sensing program, spanning from 1972 to present.
[26] The top 16 categories for Landsat imagery use, listed in order of estimated annual savings for users, are: Further uses of Landsat imagery include, but are not limited to: fisheries, forestry, shrinking inland water bodies, fire damage, glacier retreat, urban development, and discovery of new species.
Through the Landsat Menhaden and Thread Investigation, some satellite data of the eastern portion of the Mississippi sound and another area off the coast of the Louisiana coast data was run through classification algorithms to rate the areas as high and low probability fishing zones, these algorithms yielded a classification that was proven with in situ measurements – to be over 80% accurate and found that water color, as seen from space, and turbidity significantly correlate with the distribution of menhaden – while surface temperature and salinity do not appear to be significant factors.
Water color – measured with the multispectral scanners four spectral bands, was used to infer Chlorophyll, turbidity, and possibly fish distribution.
[27] An ecological study used 16 ortho-rectified Landsat images to generate a land cover map of Mozambique's mangrove forest.
Historic drought and a significant number of lightning strikes were some of the factors that created conditions for the massive fire, but anthropogenic actions amplified the disaster.
It has helped understanding of how different features and vegetation fuel fires, change temperature, and affect the spreading speed.
[30][31] The serial nature of Landsat missions and the fact that is the longest-running satellite program gives it a unique perspective to generate information of Earth.
Glacier retreat in a big scale can be traced back to previous Landsat missions, and this information can be used to generate climate change knowledge.
During FY2014 financial planning "appropriators chided NASA for unrealistic expectations that a Landsat 9 would cost US$1 billion, and capped spending at US$650 million" according to a report by the Congressional Research Service.
[7] In April 2015, NASA and the USGS announced that work on Landsat 9 had commenced, with funding allocated for the satellite in the president's FY2016 budget, for a planned launch in 2023.
[34] Funding for the development of a low-cost thermal infrared (TIR) free-flying satellite for launch in 2019 was also proposed, to ensure data continuity by flying in formation with Landsat 8.
