ENVISAT Advanced Synthetic Aperture Radar (ASAR) UK imagery
Dataset
Update Frequency: Not Planned
Status: Completed
Online Status: ONLINE
Publication State: Published
Publication Date: 2014-08-18
Download Stats: last 12 months
 
Abstract

Data from the Advanced Synthetic Aperture Radar (ASAR) on-board ENVISAT are available for the UK from 2002-2009. The raw data for the alternating polarisation, wide swath and image modes were acquired by the Landmap project from ESA and processed to produce 8 and 32-bit greyscale and multi-difference colour composite geotiff images. The Joint Information Systems Committee (JISC) funded Landmap service which ran from 2001 to July 2014 collected and hosted a large amount of earth observation data for the majority of the UK. After removal of JISC funding in 2013, the Landmap service is no longer operational, with the data now held at the NEODC.

When using these data please also add the following copyright statement: © ESA 2004/2005/2006/2007/2008…. Received and Distributed by University of Manchester under licence from the European Space Agency

Citable as:  Landmap; European Space Agency (2014): ENVISAT Advanced Synthetic Aperture Radar (ASAR) UK imagery. NERC Earth Observation Data Centre, date of citation. http://catalogue.ceda.ac.uk/uuid/86a063c7f894cd9eceb6e542888a13ea
Keywords:  Not defined
In support of:
Previous Info:
No news update for this record
Previously used record identifiers:
http://badc.nerc.ac.uk/view/neodc.nerc.ac.uk__ATOM__ACTIVITY_1162345e-2779-11e4-9928-00163e251233
Access rules:
Restricted data: please submit an application using the REQUEST ACCESS link for access.
Use of these data is covered by the following licence: http://licences.ceda.ac.uk/image/data_access_condition/landmap.pdf. When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Abbreviation:
Not defined
Data lineage:

Data collected and prepared by the Landmap team before a copy of the data were obtained by NEODC directly from Landmap.

File Format:
Data availability and file format

The data are available in geotiff format which can be opened in many earth observation image processing software including open/free software such as Erdas ER viewer and the freely available Basic ERS & Envisat (A)ATSR and Meris Toolbox (BEAM) or NEST (Next ESA SAR Toolbox). Geotiff files are TIFF files which have geographic metadata embedded as tags within the TIFF file. The geographic metadata can then be used to position the image in the correct location and geometry on the screen of a geographic information display. The data are split into the three modes acquired by Landmap (alternating polarisation, wide swath and image modes). The various polarisations can be determined from the filename:

  • hh - Horizontal polarisation transmitted, horizontal received.
  • vv - Vertical transmitted, vertical received
  • hv - Horizontal transmitted, vertical received
  • vh - Vertical transmitted, horizontal received
Specific products include 32 bit _geo GeoTiff, and 8 bit _geo_lia and _geo_ls_mask GeoTiffs. All the geotiff images are provided with GeoTiff World Files (.tfw) which are used to geo-reference images to an appropriate projection scheme.

More Information (under review)

Introduction

Data from the Advanced Synthetic Aperture Radar (ASAR) on-board ENVISAT is available for the UK from 2002-2009. The raw data for alternating polarisation, wide swath and image modes were acquired by the Landmap project from ESA and processed to produce 8 and 32-bit greyscale and multi-difference colour composite geotiff images.

  • Image mode: Provides high resolution (30m) for HH and VV polarisation products
  • Alternating Polarisation (AP): 30m resolution data in the following polarisations (each AP mode has 2 polarisations) – HH/VV, HH/HV, VV/VH
  • Wide swath: 150m resolution data in VV or HH polarisations over a wider sampling area.
The polarisations are:
  • HH - Horizontal polarisation transmitted, horizontal received
  • VV - Vertical transmitted, vertical received
  • HV - Horizontal transmitted, vertical received
  • VH - Vertical transmitted, horizontal received

The Joint Information Systems Committee (JISC) funded Landmap service which ran from 2001 to July 2014 collected and hosted a large amount of earth observation data for the majority of the UK. After removal of JISC funding in 2013, the Landmap service is no longer operational, with the data now held at the NEODC.


Restricted Data Access

The ASAR data are available to UK academics and students. To apply for access, please

  1. Register as a NEODC user. If you already are a NEODC registered user, skip this step. If you have forgotten your NEODC user ID and/or password, please contact the NEODC helpdesk at neodc@rl.ac.uk.
  2. Apply for access to the Landmap data. Application involves the agreement with the Landmap terms of use.


Data availability and file format

The data are available in geotiff format which can be opened in many earth observation image processing software including open/free software such as Erdas ER viewer and the freely available Basic ERS & Envisat (A)ATSR and Meris Toolbox (BEAM) or NEST (Next ESA SAR Toolbox). Geotiff files are TIFF files which have geographic metadata embedded as tags within the TIFF file. The geographic metadata can then be used to position the image in the correct location and geometry on the screen of a geographic information display. The data are split into the three modes acquired by Landmap (alternating polarisation, wide swath and image modes). The various polarisations can be determined from the filename:

  • hh - Horizontal polarisation transmitted, horizontal received.
  • vv - Vertical transmitted, vertical received
  • hv - Horizontal transmitted, vertical received
  • vh - Vertical transmitted, horizontal received
Specific products include 32 bit _geo GeoTiff, and 8 bit _geo_lia and _geo_ls_mask GeoTiffs. All the geotiff images are provided with GeoTiff World Files (.tfw) which are used to geo-reference images to an appropriate projection scheme.


Software

Erdas ER viewer, available free of charge, can be used to open raster image formats such as TIFF, GeoTiff, IMG, ECW, ERS, ALG, DAT and many more, and is capable of handling large file sizes.

Basic ERS & Envisat (A) ATSR and Meris Toolbox (BEAM): BEAM is an open-source toolbox and development platform for viewing, analysing and processing of remote sensing raster data. Originally developed to facilitate the utilisation of image data from Envisat's optical instruments, BEAM now supports a growing number of other raster data formats such as GeoTIFF and NetCDF as well as data formats of other Earth Observation (EO) sensors such as Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Very High Resolution Radiometer (AVHRR), AVNIR, Polarised Radiation Imaging and Spectroscopy Mission (PRISM) and Compact High Resolution Imaging Spectrometer (CHRIS). Various data and algorithms are supported by dedicated extension plug-ins.

NEST (Next ESA SAR Toolbox) is an ESA open source toolbox under the GNU GPL license for reading, processing, analysing and visualising ESA (ERS-1/2, ENVISAT, SENTINEL-1) and other spaceborne SAR data (TerraSAR-X, RADARSAT 1-2, COSMO-SkyMed, JERS-1, ALOS PALSAR) processed to Level-1 or higher.

Documentation

Links to further information

  • The Landmap project ASAR website, this site may be offline soon after 1st August 2014 due to removal of JISC (Joint Information Systems Committee) funding, see below for an archived version of ths site
  • An archived version of the Landmap project ASAR site, hosted by the Internet Archive project
  • The ESA ASAR website


Who to contact

If you have queries about these pages or about obtaining the ASAR data from the NEODC then you should contact the NEODC Support team. Your query should be answered within one working day. When follow-up work is required, the NEODC support team will carry out the work as quickly and efficiently as possible.

Process overview
This dataset was generated by a combination of instruments deployed on platforms and computations as detailed below.

Instrument/Platform pairings

Deployed on: Envisat

Mobile Platform Operation 1
Output Description
None

Computation Element: 1

Title
Satellite deployed on Envisat
Abstract
Envisat.
Input Description
None
Output Description
None
Software Reference
None
There are no comments about this dataset
Temporal Range
2002-01-01T00:00:00
2009-12-31T00:00:00
Geographic Extent

  60.9000°  
-9.0000°     1.7000°
  50.0000°  
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