OR/17/006 Remote sensed datasets
|Monaghan, A A, Dochartaigh, B O, Fordyce, F, Loveless, S, Entwisle, D, Quinn, M, Smith, K, Ellen, R, Arkley, S, Kearsey, T, Campbell, S D G, Fellgett, M, and Mosca, I. 2017. UKGEOS - Glasgow geothermal Energy Research Field Site (GGERFS): initial summary of the geological platform. British Geological Survey Open Report, OR/17/006.|
A summary of the availability of remote sensed (earth observation) data and the main uses of each data type relevant to the Clyde Gateway area is given below.
Landsat 8 optical and thermal imagery
The Landsat 8 satellite hosts 1)the OLI (Operational Land Imager), a satellite sensor that captures medium (30 m) spatial resolution data in 9 spectral bands: 5 visible (VIS); 1 Near-infrared (NIR); 2 shortwave infrared (SWIR); and 1 Panchromatic (PAN) at higher (15 m) spatial resolution; and 2) the TIRS (Thermal Infrared Sensor) that captures data in 2 medium (100 m) spatial resolution Thermal Infrared (TIR) bands.
The data are used to continuously, systematically and consistently assess changes in Earth's landscape, study and monitor landmasses, and create a historical archive of spectral information from the Earth's surface for use in agriculture, geology, forestry, regional planning, education, mapping, and global change, characterisation of urban growth, emergency response and disaster relief. Landsat 8 (2013-present) is the continuity mission for Landsat 7 (Enhanced Thematic Mapper Plus), which was launched in 1999 but developed sensor technical issues in 2003.
- Landsat 8 imagery is free and there are established processing algorithms
- Accessible through www.earthexplorer.usgs.gov
- No limitations in redistribution of BGS-processed imagery, with acknowledgement to USGS
- 16-day repeat with 2 potential images from Path/Row: 205/021 and 206/021
- Some limited cloud-free images are available for the Clyde Gateway area
- LC8: Path 205 / Row 21: 25/10/2016; 28/02/2016; 05/11/2014; 04/12/2013
- LC8: Path 206 / Row 21: 01/11/2016; 09/05/2016; 23/07/2014; 18/04/2014; 20/07/2013
Aster optical and thermal imagery
ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is a satellite sensor that captures high spatial resolution data in 14 spectral bands, including 3 bands in Visible and Near Infrared (VNIR) at 15 m, 6 bands in Shortwave Infrared (SWIR) at 30 m and 5 bands in Thermal Infrared (TIR) at 90 m; it also provides stereo viewing capability for digital elevation model creation. ASTER data is used to obtain detailed maps of land surface temperature, reflectance and elevation, and to observe, understand, and model the recent changes of the Earth system. It has applications for topographic mapping, land-use/cover mapping, monitoring surface/land temperature, emissivity, reflectance and elevation changes. ASTER was launched in 1999 but developed a technical fault with SWIR data in 2008.
- ASTER data are free and there are established processing algorithms
- Accessible through www.reverb.echo.nasa.gov
- No limitations in redistribution of BGS-processed imagery, with acknowledgement to NASA
- Some limited cloud-free images are available over the Clyde Gateway area
- 25/08/2000 - AST_L1B_003_20000825115426.hdf
- 01/05/2001 - AST_L1B_003_20010501114324.hdf
- 31/03/2007 - AST_L1B_003_20070331113344.hdf
High spatial resolution optical satellite imagery
There are a number of satellite platforms that acquire high spatial resolution optical imagery at visible, near-infrared and shortwave infrared wavelengths. Current platforms are WorldView-1 (2007-present), GeoEye-1 (2008-present), WorldView-2 (2009-present), Pleiades (2011-present), SkySat-1 (2013-present), WorldView-3 (2014-present), SkySat-2 (2014-present), WorldView-4/GeoEye-2 (2016-present) as well as decomissioned QuickBird-2 (2002-2015), IKONOS (1999-2015) can provide sub-metre to metre spatial resolution in a few spectral bands. In addition there is SPOT-6 (2012-present) and SPOT-7 (2014-present) that can provide near- metre spatial resolution in a few spectral bands. Images are used to observe, understand, and model the recent changes of the Earth system and have applications for land-use/cover mapping for agriculture, geology, forestry, regional planning, education, mapping, and global change, characterisation of urban growth, emergency response and disaster relief.
- These high spatial resolution datasets can be expensive and have to be purchased through a reseller (i.e. Airbus, DigitalGlobe)
- Some cloud-free images are available over the Clyde Gateway area
- BGS is unlikely to be able to redistribute raw imagery, but some potential for processed images
High spectral and spatial resolution optical airborne imagery
NERC owns an airborne platform that can be used to acquire high spatial and spectral resolution visible and near-infrared (VNIR), shortwave infrared (SWIR) and thermal infrared (TIR) imagery using specialist airplane-mountable hyperspectral sensors. The AisaEAGLE (VNIR), AisaHAWK (SWIR), AisaFENIX (VNIR-SWIR) and AisaOWL (TIR) can be mounted in conjunction with a digital Leica photogrammetric format survey camera, the latter can be used to generate high resolution DEM, although it is more common to acquire LiDAR data at the same time (see later). The imagery can be used to investigate geoscience and environmental issues of the ground surface imaged during the survey. In order for a survey to be performed by NERC, an announcement of opportunity is opened to the science community and a science case must be written and submitted for peer-review. These targeted opportunities do not necessarily mean that the data will be acquired due to constraints and matching of weather conditions and surface conditions specified in the science case.
There have been no NERC surveys flown so far over the Clyde Gateway area.
Synthetic Aperture Radar (SAR) is an active system that transmits a beam of electromagnetic energy in the microwave region towards the ground surface and measures the backscattered response. SAR does not require solar reflected radiation or thermal emitted radiation for measurement and therefore can provide both day and night imagery of the Earth. SAR measurements are also relatively unaffected by cloud, fog or precipitation so the ground surface can be imaged independent of adverse weather conditions. SAR imagery can be used to monitor changes in the land surface through surface cover and ground motion, in addition to providing emergency mapping support in the event of natural disasters. SAR imagery has been acquired by a multitude of systems ERS-1 SAR (1991–2000), ERS-2 SAR (1995–2011), Envisat ASAR (2002–2012), Cosmo-SkyMed (2010-present), Radarsat-2 (2007–), TerraSAR-X (2007–present), TanDEM-X (2010–present) and Sentinel-1 (2014 and 2016–present). Data can be looked at as a single time-slice image or in combination with other temporal images of the same surface area to determine millimetric-precision vertical ground motion using established Interferometric (i.e. PSInSAR, IPTA and ISBAS) techniques.
- High resolution radar data can be expensive, but Sentinel-1 data are free
- The ESA Sentinel Toolbox can be used to process the Sentinel-1A and 1B data, which is accessible through www.scihub.copernicus.eu/dhus
- Nigel Press Associates (became Fugro, now CGG) were paid to process SAR imagery for ground motion of Glasgow about 14.5 years ago. BGS holds a copy of these data, probably ERS-1/-2 data with/out ENVISAT ASAR, in its archives (conditions of use require to be clarified). The area was fairly stable during that period of monitoring
- BGS staff have extensive expertise and technical background in processing satellite-borne radar data for ground motion using detailed GAMMA UNIX-based software. The only BGS software installation is node-locked in BGS Keyworth
- Dr. Zhenhong Li (Newcastle Uni, ex-Glasgow Uni) processed some SAR data of Glasgow and there is a PhD student (J.Stockamp) researching ground motion including on the Glasgow area