Authors / CoAuthors
Abstract
SPOT 1, launched in 1986 by the French Government agency, Centre National d'Etudes Spatiales, carries two High Resolution Visible (HRV) sensors. Two SPOT satellites (SPOT 2 & 3) currently orbit the earth 180 degrees apart with SPOT 2 being the nominally operational satellite but data from SPOT 3 can be acquired on request. Each HRV has a ground swath 60 kilometres wide, and can operate independently either in panchromatic (PA) or multispectral (XS) mode. SPOT 3 carries the only operational onboard tape recorders which store imagery when the sensors are operating outside the reception area of a ground station, allowing worldwide coverage by SPOT. Every 26 days, SPOT's orbit can provide total coverage of the Earth's surface, in a vertical viewing mode. Additionally, SPOT has the ability to image up to an angle of 27 degrees east or west of vertical. This can allow revisits of the same site in Australia in as little as three days, and also allows for stereo images to be acquired for use in determining the height of ground features. The archive of ACRES products includes SPOT data from 1989 onwards. The HRV multispectral (XS) sensor operates in three bands in the visible and near infrared part of the electromagnetic spectrum with a resolution of 20m. ACRES SPOT archive contains selected imagery from the following SPOT satellites: - SPOT 1 commenced 1 January 1990, ceased January 1991. - SPOT 2 commenced 1 January 1991, continuing. - SPOT 3 selected from 25 September 1993.
Product Type
dataset
eCat Id
66001
Contact for the resource
Custodian
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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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
2008-06-04T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
asNeeded
Topic Category
imageryBaseMapsEarthCover
Series Information
Lineage
The SPOT XS data set is acquired by earth orbiting remote sensing satellites. These satellites carry two types of sensor systems known as "active" and "passive". A "passive" system generally consists of an array of small sensors or detectors which record (as digital numbers) the amount of electro-magnetic radiation reflected and/or emitted from the Earth's surface. The SPOT XS is a passive system. 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. Each scene acquired by ACRES is sub-sampled and produced in its Digital Catalogue access to which is available through the WWW. 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
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