History and Features History and Features of Landsat 7of Landsat 7

By: Andy VogelsbergBy: Andy Vogelsberg

Photo of Landsat 7 taken from http://teacherlink.ed.usu.edu/tlnasa/pictures/litho/landsat/land.jpg

History of Landsat ProgramHistory of Landsat Program

The Landsat program was inspired by Apollo moon The Landsat program was inspired by Apollo moon bound missions.bound missions.

William Pecora proposed the idea of having remote William Pecora proposed the idea of having remote sensing satellites in space in 1964.sensing satellites in space in 1964.

Eight years later, his proposal became reality, and Eight years later, his proposal became reality, and the Landsat program had begun.the Landsat program had begun.

Landsat 1 was launched on July 23, 1972. Since Landsat 1 was launched on July 23, 1972. Since then, six other satellites have been launched.then, six other satellites have been launched.

Landsat 7 is the most recent satellite we have Landsat 7 is the most recent satellite we have launched, providing us the most technological data launched, providing us the most technological data possible.possible.

Landsat 7Landsat 7 Landsat 7 was launched on April 15, 1999 from Vandenberg Air Force Landsat 7 was launched on April 15, 1999 from Vandenberg Air Force

Base in California and was built to last at least 5 years. Base in California and was built to last at least 5 years.

The purpose of Landsat 7 is to replicate the capabilities of other The purpose of Landsat 7 is to replicate the capabilities of other launches, as well as provide new information.launches, as well as provide new information.

Landsat 7 can provide more information than any of the previous Landsat 7 can provide more information than any of the previous Landsat satellites at a lower cost. Landsat satellites at a lower cost.

532 images a day can be produced by Landsat 7.532 images a day can be produced by Landsat 7.

Landsat 7 orbits the earth at an altitude of 705 Kilometers and covers Landsat 7 orbits the earth at an altitude of 705 Kilometers and covers a swath width of 185 km.a swath width of 185 km.

The satellite covers the whole earth in 15 days or 232 orbits. The satellite covers the whole earth in 15 days or 232 orbits.

Landsat 7 weighs 1973 kg.Landsat 7 weighs 1973 kg.

The observing instrument on board Landsat 7 is the Enhanced The observing instrument on board Landsat 7 is the Enhanced Thematic Mapper Plus (ETM+).Thematic Mapper Plus (ETM+).

Enhanced Thematic Mapper PlusEnhanced Thematic Mapper Plus(ETM+)(ETM+)

The ETM+ was also used on Landsats 4 and 5.The ETM+ was also used on Landsats 4 and 5.

Landsat 7’s ETM+ has features that other satellites Landsat 7’s ETM+ has features that other satellites did not.did not.

These features make Landsat 7 a more useful These features make Landsat 7 a more useful component for studies in global change, monitoring component for studies in global change, monitoring of land cover, and mapping large areas.of land cover, and mapping large areas.

Image of Landsat 7 ETM+ taken from:http://landsat.usgs.gov/project_facts/history/images/ETM+instrument.jpg

Components of Landsat 7Components of Landsat 7

A drawing of Landsat 7 taken from: http://directory.eoportal.org/images/LS7_Auto4.jpeg

Advantages of Landsat 7’s ETM+Advantages of Landsat 7’s ETM+

Landsat 7’s ETM+ is different from previous thematic Landsat 7’s ETM+ is different from previous thematic mappers because it offers:mappers because it offers:

a panchromatic band with 15m spatial resolution a panchromatic band with 15m spatial resolution on-board, full aperture, 5% absolute radiometric on-board, full aperture, 5% absolute radiometric

calibration calibration a thermal IR channel with 60m spatial resolution a thermal IR channel with 60m spatial resolution an on-board data recorderan on-board data recorder

(Bulleted data taken directly from (Bulleted data taken directly from http://landsat.gsfc.nasa.gov/about/landsat7.htmlhttp://landsat.gsfc.nasa.gov/about/landsat7.html))

Malfunction on Landsat 7Malfunction on Landsat 7 On May 31, 2003 Landsat 7 experienced its first problems.On May 31, 2003 Landsat 7 experienced its first problems.

The Scan Line Protector (SLC) on board Landsat 7 failed. The Scan Line Protector (SLC) on board Landsat 7 failed. The problem created narrow bands on images formed by The problem created narrow bands on images formed by Landsat 7 to be missing. Landsat 7 to be missing.

These narrow bands were caused because image scanning These narrow bands were caused because image scanning in the SLC was at an angle instead of being parallel. in the SLC was at an angle instead of being parallel.

To this day, the malfunction of the SLC is still affecting To this day, the malfunction of the SLC is still affecting images acquired by the satellite.images acquired by the satellite.

Landsat 7 loses approximately 22% on each image it Landsat 7 loses approximately 22% on each image it acquires because the SLC is not operable. acquires because the SLC is not operable.

Methods are being done by the USGS to duplicate all Methods are being done by the USGS to duplicate all missing data due to the malfunction of the SLC.missing data due to the malfunction of the SLC.

Affects of No SLCAffects of No SLC The SLC’s job was to compensate for the forward The SLC’s job was to compensate for the forward

motion of Landsat 7.motion of Landsat 7.

Without it, a zig zag motion is created. (bottom Without it, a zig zag motion is created. (bottom left)left)

The photo on the right shows the affected area The photo on the right shows the affected area created without no SLC.created without no SLC.

Images taken from http://landsat.usgs.gov/data_products/slc_off_data_products/slc_off_background.php

Major Advantages of Landsat 7Major Advantages of Landsat 7 Landsat 7 continues to give us high-quality data with the ETM+ which Landsat 7 continues to give us high-quality data with the ETM+ which

dates back to Landsat 4 in 1982. Since data looks similar, global change dates back to Landsat 4 in 1982. Since data looks similar, global change is easy to detect from pre-existing archives.is easy to detect from pre-existing archives.

Data acquisition is optimum, because Landsat 7 takes all photos in sun lit Data acquisition is optimum, because Landsat 7 takes all photos in sun lit conditions. Information from NOAA is also used to keep images cloud conditions. Information from NOAA is also used to keep images cloud cover minimal. cover minimal.

Landsat 7 can obtain and store more data faster than any other form of Landsat 7 can obtain and store more data faster than any other form of remote sensing instrument. remote sensing instrument.

The data collected by the satellite is easy to get through the USGS or The data collected by the satellite is easy to get through the USGS or EROS at an affordable price. EROS at an affordable price.

The Landsat 7's ETM+ has been called "the most stable, best The Landsat 7's ETM+ has been called "the most stable, best characterized Earth observation instrument ever placed in orbit."characterized Earth observation instrument ever placed in orbit."

(Taken from (Taken from http://landsat.gsfc.nasa.gov/about/landsat7.htmlhttp://landsat.gsfc.nasa.gov/about/landsat7.html))

Landsat 7’s ETM+ has also set the standard on accuracy for all other Landsat 7’s ETM+ has also set the standard on accuracy for all other remote sensing systems. The ground accuracy acquired through Landsat remote sensing systems. The ground accuracy acquired through Landsat 7’s data is second to none.7’s data is second to none.

Controllers of Landsat 7Controllers of Landsat 7

The Flight Operations Team (FOT) is in charge of command The Flight Operations Team (FOT) is in charge of command control as well as telemetry operations for Landsat 7.control as well as telemetry operations for Landsat 7.

All controls of the sattelite take place in the Mission All controls of the sattelite take place in the Mission Operation Center in the Goddard Space Flight Center which Operation Center in the Goddard Space Flight Center which is located in Greenbelt Maryland. is located in Greenbelt Maryland.

Data is captured from the sattelite in both Sioux Falls SD, as Data is captured from the sattelite in both Sioux Falls SD, as well as Alice Springs Australia. well as Alice Springs Australia.

Backup sites are also located in Poker Flat Alaska and Backup sites are also located in Poker Flat Alaska and Svalbard Norway.Svalbard Norway.

Mission Operations CenterMission Operations Center

http://ls7pm3.gsfc.nasa.gov/mainpage.html

http://ls7pm3.gsfc.nasa.gov/mainpage.html

Images Taken by Landsat 7Images Taken by Landsat 7

medias.obs-mip.fr/.../en/systemes/landsat.html

gisdata.usgs.net/.../categories.asp?catid=10

landsat.usgs.gov/gallery/detail/411/

Top Left: Cap Canaveral Launching Site

Middle: Flooding in South Africa

Top Right: Flooding in New Orleans due to Hurricane Katrina

Composite Images of Landsat 7Composite Images of Landsat 7

Left Image: True Color Composite (Bands 321)Left Image: True Color Composite (Bands 321) Middle Image: Near Infrared Composite (Bands 432)Middle Image: Near Infrared Composite (Bands 432) Right Image: Short-wave Infrared Composite (Bands 742)Right Image: Short-wave Infrared Composite (Bands 742)

chesapeake.towson.edu/data/all_composite.asp

ReferencesReferences National Aeronautics and Space Administration, Landsat 7, World Wide Web National Aeronautics and Space Administration, Landsat 7, World Wide Web

URL: URL: http://landsat.gsfc.nasa.gov/about/landsat7.htmlhttp://landsat.gsfc.nasa.gov/about/landsat7.html

Wikipedia, The Free Encyclopedia, Landsat 7, World Wide Web URL: Wikipedia, The Free Encyclopedia, Landsat 7, World Wide Web URL: http://en.wikipedia.org/wiki/Landsat_7http://en.wikipedia.org/wiki/Landsat_7

National Aeronautics and Space Administration, Landsat 7 Science Data National Aeronautics and Space Administration, Landsat 7 Science Data

Users Handbook, World Wide Web URL: Users Handbook, World Wide Web URL: http://landsathandbook.gsfc.nasa.gov/handbook.htmlhttp://landsathandbook.gsfc.nasa.gov/handbook.html

National Aeronautics and Space Administration, SLC-off Products: National Aeronautics and Space Administration, SLC-off Products: Background, World Wide Web URL: Background, World Wide Web URL: http://landsat.usgs.gov/data_products/slc_off_data_products/slc_off_background.phphttp://landsat.usgs.gov/data_products/slc_off_data_products/slc_off_background.php

Landsat 7, Supplying data users worldwide with low cost, multi-purpose, Landsat 7, Supplying data users worldwide with low cost, multi-purpose, land remote sensing data into the next centuryland remote sensing data into the next century, World Wide Web URL: , World Wide Web URL: http://geo.arc.nasa.gov/sge/landsat/l7.htmlhttp://geo.arc.nasa.gov/sge/landsat/l7.html

Landsat 7 Home Page, World Wide Web URL: Landsat 7 Home Page, World Wide Web URL: http://ls7pm3.gsfc.nasa.gov/mainpage.htmlhttp://ls7pm3.gsfc.nasa.gov/mainpage.html