Authors / CoAuthors
Unknown
Abstract
Two ERS satellites have been developed by the European Space Agency (ESA). ERS-1 was launched on 17 July 1991 and ERS-2 on 20 April 1995. Both ERS satellites travel at an altitude of 785 kilometres and provide coverage of the entire globe every 35 days. The C-band, Synthetic Appeture Radar (SAR) sensor has been the primary Earth-observing instrument. The SAR is an active microwave sensor capable of imaging earth resource targets regardless of time of day, cloud, haze or smoke cover of an area. The instrument is classified "active" as it emits the energy necessary to image the earth's surface. In contrast, "passive" or "optical" sensors rely on the sun's reflected energy to image the earth. The SAR ground swath is 102.5 kilometres wide, with a nominal 30 metre pixel resolution. The sensor has VV polarisation. ACRES ERS-1 archive includes data acquired from September 1991 to March 2000, while ACRES ERS-2 acquisitions started in November 1995 and continues to present.
Product Type
dataset
eCat Id
47927
Contact for the resource
Custodian
Owner
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- Satellite ImageryERS
- ( Theme )
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- satellite imagery
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
Publication Date
2003-06-17T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
continual
Topic Category
imageryBaseMapsEarthCover
Series Information
Lineage
The ERS SAR data set is acquired by earth orbiting remote sensing satellites. These satellites carry two types of sensor systems known as "active" and "passive". The ERS SAR instrument is classified as "active" as it emits the energy necessary to image the earth's surface. The digital data acquired by the satellites are transmitted to ground stations and can be used to reconstitute an image of the Earth's surface not too dissimilar to an aerial photograph. Data are received through the ACRES antenna at the Data Acquisition Facility at Alice Springs enabling coverage of the Australian landmass. The recorded data are air-freighted daily to the Data Processing Facility in Canberra where it is catalogued and archived. Data are recorded and archived by path, or swath, allowing coverage of any region in the path to be extracted by its geographical coordinates. If the region of interest extends across two adjacent paths the appropriate data set from each path will need to be extracted. Because of the orbital parameters of the satellite, adjacent paths are not acquired sequentially and information from each path may differ according to the time delay between the two passes. To assist cataloguing and ordering, a path is segmented into individual scenes the length of each scene being the same as the path width. Each scene can be related to geographical coordinates using the Path/Row reference system. The Path is the number of the satellite swath (east to west) across Australia and the Row is the number of the scene south of the equator. Diagrams and formulae are available to assist in relating geographical coordinates to the satellite scene Path/Row coordinates. Data are provided as hard copy photographic data products, or as digital data products which can be viewed and manipulated on a variety of software systems. However, the data transmitted to Earth from an Earth observation satellite are in a form unsuitable for use by customers so ACRES processes this raw data in varying degrees to produce products suitable for use by clients. ACRES only processes the data after a client has placed an order for a specific product. This is due to the large quantities of data received from a satellite and the large range of product options available.
Parent Information
Extents
[-90.0, -9.0, 45.0, 168.0]
Reference System
Spatial Resolution
Service Information
Associations
Source Information
Source data not available.