About Remote Sensing

What is Remote Sensing?

Remote sensing is the observation of an object from a distance. Examples are Aerial Photography and the use of satellites to observe the Earth.

What is Satellite Remote Sensing?

Satellite remote sensing involves gathering information about features on the Earth's surface from orbiting 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. A multispectral scanner is an example of a passive system. An "active" system propagates its own electro-magnetic radiation, and measures (as digital numbers), the intensity of the return signal. Synthetic Aperture Radar (SAR) is an example of an active system.

The digital data acquired by the satellites is transmitted to ground stations and can be used to reconstitute an image of the Earth's surface not too dissimilar to an aerial photograph.

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Benefits of remotely sensed data from Earth Observation Satellites

Remotely sensed data acquired by the Earth observation satellites provides a number of benefits for studying the Earth's surface, including:

• continuous acquisition of data
• regular revisit capabilities (resulting in up-to-date information)
• broad regional coverage
• good spectral resolution (including infra-red bands)
• good spatial resolution
• ability to manipulate/enhance digital data
• ability to combine satellite digital data with other digital data
• cost effective data
• map-accurate data
• possibility of stereo viewing
• large archive of historical data

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How is data provided to the end-user?

Data is provided as digital data products which can be viewed and manipulated on a variety of software systems. See ACRES Products and Services page for further information.

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How is data used?

Satellite data is used to provide timely and detailed information about the Earth's surface, especially in relation to the management of our renewable and non-renewable resources.

Some examples of uses of satellite data are:

• assessment and monitoring of vegetation types and their status
• soil surveys
• mineral exploration
• map making and revision
• production of thematic maps
• water resources planning and monitoring
• urban planning
• agricultural property management planning
• crop yield assessment
• natural disaster assessment
  
  
• See this Case study for satellite data use:Remote Sensing and Landcare

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Earth Observation Satellites

ACRES downlinks from Earth observation satellites such as Landsat, ERS and RADARSAT. See ACRES Satellite Facts Page for more information on the current status of these satellites.

View current locations of satellites

To view the visualisation tool, please go to http://www.ga.gov.au/acres/acres_view.jsp