Long-term datasets of satellite data are very useful in ongoing studies, particularly in the field of Change Detection.
This data allows scientists to examine an area over a period of time, and see what changes (if any) are indicated, and determine the cause. Not only are the data of use in studying the past, but they can be used to forecast future changes based on past trends.
Deforestation, Polar ice loss and Climate Change studies all make use of satellite data to monitor their particular fields. The rate and extent of forest loss and ice melt can be tracked, as well as overall trends of change in our world's climate.
ESA has developed a large archive of this data from their satellites, particularly the two ERS missions and Envisat. Combined, the three satellites acquired data over the Earth for a period of 31 years. And from 2014 the Sentinel satellites will add to this archive with new imagery.
Beyond static comparisons of images acquired over the duration of the mission, methods have been developed to merge these images. They can be combined into one "multi-temporal" image that highlights the changes in a location over a period of time.
Latest Change Detection Events
19 July 2018 - Nairobi, the capital city of Kenya, is featured in this Sentinel comparison. Nairobi is demonstrated using Sentinel-1 and -2 imagery to emphasise the difference between the radar and optical images the satellites provide.
13 July 2018 - This image comparison features the Mount Etna Volcano in Sicily, Italy. The Copernicus Sentinel-2 is utilised to capture the state of Mount Etna Volcano, using natural and false colour imagery.
29 June 2018 - These image comparisons feature the state of Saemangeum Seawall in South Korea. The Landsat-4, Landsat-8 and the Copernicus Sentinel-2 are utilised to capture the developmenta around the Saemangeum Seawall from 1989 to 2018, using natural and false colour imagery.
21 June 2018 - Berlin, the capital city of Germany, is featured in this Sentinel comparison. Berlin is demonstrated using Sentinel-1 and -2 imagery to emphasise the difference between the radar and optical images the satellites provide.
30 May 2018 - Kīlauea Volcano is located on Hawaii's Big Island and has been active for decades. Landsat 8 was used to monitor the state of the volcano during the latest eruption in May.
17 May 2018 - This weeks Earth Watching comparison shows the city of Beirut, Lebanon and its Mediterranian coastline. Sentinel-1 and 2 imagery is used here to emphasise the difference between the radar and optical images the satellites provide.
11 May 2018 - These image comparisons from the Landsat-5, -8 and Copernicus Sentinel-2 satellites feature the capital of Syrian Arab Republic - Damascus and show that this city has undergone significant developmental change since 1987.
30 April 2018 - Los Angeles, the most populous city in the state of California, is featured in this Sentinel comparison. Los Angeles is shown using Sentinel-1 and -2 imagery to emphasise the difference between the radar and optical images the satellites provide.
Showing 1 - 8 of 183 results.
Earth Watching Links