New life for Landsat historical data
01 April 2020
45 years of data, more than 1.8 million images, these are the numbers of an adventure started 48 years ago with the launch of the first Landsat satellite. Today, the entire Landsat Multispectral Scanner (MSS) ESA dataset has been processed with improved algorithms, so as to offer top quality data to the user community.
Landsat is the pioneering US land remote sensing satellite program, which has provided a continuous supply of synoptic, repetitive, multispectral data of Earth's land surfaces since 1972. Over the years, a large international user community evolved along with the Landsat series.
The programme opened entirely new fields of research, providing insights into geologic, agricultural, and land-use surveys, eventually leading to new paths of resource exploration - in all, for a better understanding of our planet's system.
The primary mission objective was to monitor Earth's resources to achieve periodic and complete coverage of the United States via multispectral, high spatial resolution images of solar radiation reflected from Earth's surface.
Secondary objectives included acquisition of multispectral images over important major land masses other than the United States, at least once per season, and the relay of data acquired by International ground stations from the Landsat satellites to a central analysis facility, to support the modelling of Earth resource oriented processes.
The success of the Landsat programme stimulated new approaches to data analysis and gave impetus to new sensor designs: for instance, the Copernicus Sentinel-2 sensor was designed in order to keep full compatibility with this fundamental dataset and expand it in terms of spatial and frequency resolutions.
From 1975, ESA began with its own ground systems, to acquire, process and archive data from Landsat, under the Earthnet program. Starting with a single satellite ground station, located in Fucino (Italy), the acquisition capability was increased in the following years with Kiruna (Sweden), Maspalomas (Canary Islands – Spain), Matera (Italy) and Neustrelitz (Germany). The resulting dataset of the seven Landsat satellites, with over 1.8 million scenes, is now fully available under Earthnet's Third Party Missions (TPM).
As part of the International Ground Station (IGS) community, ESA is continuously maintaining efforts to distribute new Landsat 8 data.
ESA's 45 years worth of Landsat historical data observed over Continental Europe, African regions and the Arctic has become massive.
Major efforts have been undertaken to improve processing and then produce the most up to date Level-1 products for the community.
The Multi Spectral Scanner (MSS) instrument on board the Landsat 1 to 5 satellites was built by SBRC (Santa Barbara Research Center) of Hughes Aircraft Company in Goleta, CA.
The objective of MSS was to provide repetitive, daytime acquisition of high-resolution, multispectral data of Earth's surface on a global basis, and to demonstrate that remote sensing from space is a feasible and practical approach, to efficiently manage Earth's resources.
MSS is an opto-mechanical scanning instrument (whiskbroom technique, unidirectional operation) consisting of a double reflector-type telescope, scanning mirror, filters, detectors, and associated electronics. The MSS instrument had a spatial resolution of approximately 79 metres with four bands ranging from the visible green to the Near Infra-Red (NIR).
This is the first time that ESA's Landsat MSS collection (data acquired over the visibility masks of Fucino, Kiruna and Maspalomas from 1975 to 1999) has been systematically processed. This processing started some years ago, and it highlighted and made it possible to understand issues that for years had affected the data, but had never been correlated with an on-request processing scheme. By systematically producing all of the scenes of a single satellite pass, the information of the adjacent scenes has been used to improve the geometry of partially clouded scenes.
The analysis of Level-0 data revealed that multispectral scanner calibration was not optimal, leading to saturation in bright areas (ice/snow and desert). For these regions, the calibration coefficients were revised and most data are now almost free from saturation.
A quality information map, compatible with the one developed by USGS for Landsat TM data, is now attached to Level-1 MSS products, indicating problematic, cloudy, water and saturated pixels.
The result is that MSS data are now fully comparable with the data coming from the more modern instruments carried on board of the recent Landsat missions, TM (Landsat 5), ETM+ (Landsat 7) and OLI/TIRS (Landsat 8) and even with Copernicus Senitnel-2.
Andrea Schedid, Third Party Missions Operation Coordination Manager, states, "These improved MSS data are allowing users to benefit from a huge range of images, which ensure a better comparison of older data to recent ones, thus bringing Earth observation to a new level."
Roberto Biasutti, Payload Data Ground Segment Operational Manager, adds, "This incredible collection is expanding the remote sensing data availability over European and North African countries as far as 1975: 45 years of data continuity and the adventure is continuing with Landsat and Copernicus Sentinel-2 satellites series—Amazing!"
Title: Snow/Ice equilibrium line
Description: The new Landsat MSS collection allows to perform change detection studies on a long period observation: in this case the status of one of the most famous Alps glaciers. We can see how the equilibrium snow/ice line of Aletsch glacier (Switzerland) changed in the last 40 years.
Copyright: © ESA 1975-2017, Contains modified Copernicus Sentinel data (2016)/ Movie produced by ESA-IDEAS+
Title: Land changes over Toulouse
Description: This animation features the urban growth, forest and agricultural practice changes over Toulouse, France, from 1975 to 2017 with the MSS instrument of the Landsat satellites.
Copyright: © ESA 1975-2017 Movie produced by ESA-IDEAS+
|Date of Launch:|
|08 April 2010|
|LEO, non Sun-synchronous|
CryoSat's primary payload is the SAR/Interferometric Radar Altimeter (SIRAL) which has extended capabilities to meet the measurement requirements for ice-sheet elevation and sea-ice freeboard.
CryoSat also carries three star trackers for measuring the orientation of the baseline. In addition, a radio receiver called Doppler Orbit and Radio Positioning Integration by Satellite (DORIS) and a small laser retroreflector ensures that CryoSat's position will be accurately tracked.
More detailed information on CryoSat instruments is available on the CryoSat mission page.
The following CryoSat datasets are available and distributed to registered users:
- Level 1B and L2 Ice products: FDM, LRM, SAR and SARIn
- Consolidated Level 2 (GDR): (LRM+SAR+SARIN) consolidated ice products over an orbit
- Intermediate Level 2 Ice products: LRM, SAR and SARIn
- L1b and L2 Ocean Products: GOP and IOP
Detailed information concerning each of the above datasets is available in the CryoSat Products Overview and in the news item: CryoSat Ocean Products now open to scientific community.
CryoSat Level 1B altimetric products contain time and geo-location information as well as SIRAL measurements in engineering units. Calibration corrections are included and have been applied to the window delay computations. In Offline products, geophysical corrections are computed from Analysis Auxiliary Data Files (ADFs), whereas in FDM products corrections are computed for Forecast ADFs. All corrections are included in the data products and therefore the range can be calculated by taking into account the surface type.
The Offline Level 2 LRM, SAR and SARIn ice altimetric products are generated 30 days after data acquisition and are principally dedicated to glaciologists working on sea-ice and land-ice areas. The Level 2 FDM products are near-real time ocean products, generated 2-3 hours after data acquisition, and fulfill the needs of some ocean operational services. Level 2 products contain the time of measurement, the geo-location and the height of the surface.
IOP and GOP are outputs of the CryoSat Ocean Processor. These products are dedicated to the study of ocean surfaces, and provided specifically for the needs of the oceanographic community. IOP are generated 2-3 days after data sensing acquisition and use the DORIS Preliminary Orbit. GOP are typically generated 30 days after data sensing acquisition and use the DORIS Precise Orbit. Geophysical corrections are computed from the Analysis ADFs, however following the oceanographic convention the corrections are available but not directly applied to the range (as for FDM).
|Temporal coverage:||2010 - Present|
European Space Agency, 2019, L1b LRM Precise Orbit. Baseline D. https://doi.org/10.5270/CR2-cbow23i
European Space Agency, 2019, L1b SAR Precise Orbit. Baseline D. https://doi.org/10.5270/CR2-2cnblvi
European Space Agency, 2019, L1b SARin Precise Orbit. Baseline D. https://doi.org/10.5270/CR2-u3805kw
European Space Agency, 2019, L2 LRM Precise Orbit. Baseline D. https://doi.org/10.5270/CR2-k1o4pyh
European Space Agency, 2019, L2 SAR Precise Orbit. Baseline D. https://doi.org/10.5270/CR2-53hztdl
European Space Agency, 2019, L2 SARin Precise Orbit. Baseline D. https://doi.org/10.5270/CR2-gsyvnx0
European Space Agency, 2019, GDR Precise Orbit. Baseline D. https://doi.org/10.5270/CR2-he6wfkr
|NOAA, NASA, USGS|
|Date of Launch:|
|23 July 1972|
|Out of service|
This dataset contains all the Landsat 1 to 5 Multi Spectral Scanner (MSS) Level 1 GEO (geometrically corrected, L1G) and GTC (geometrically and terrain corrected, L1T) products acquired from 1975 to 1999 through the Kiruna, Maspalomas and Matera ESA stations. As a consequence, the special coverage coincides with the visibility masks of above stations, as depicted in below density maps.
Two different product levels are available:
- Geometrically and terrain corrected GTC Products (L1T): The most accurate level of processing as they incorporate Ground Control Points (GCPs) and a Digital Elevation Model (DEM) to provide systematic geometric and topographic accuracy; with geodetic accuracy dependent on the number, spatial distribution and accuracy of the GCPs over the scene extent, and the resolution of the DEM used.
- Geometrically corrected GEO Product (L1G): Normally generated where there is a lack of GCPs, and are derived purely from data collected by the sensor and spacecraft e.g. ephemeris data.
71 N, 22 S, 24 W, 44 E
|Temporal coverage:||01/01/1975 - 31/12/1999|
Swarm Bravo: Scalar magnetic field data not available from 17 to 22 March 2020
31 March 2020
Due to an issue detected in the Swarm L1B data processing chain, the magnetic field intensity derived from the ASM instrument and stored in MAGx_LR_1B and MAGx_CA_1B products for Swarm Bravo is set to zero from 17 to 22 March 2020. This data gap will be recovered soon.