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Satellite imaging of pastures: Frequently Asked Questions The
pastures from space group is a consortium comprising CSIRO Livestock Industries,
the Western Australian Department of Agriculture (DAWA), and the Western Australian Land Information Authority (Landgate). The
project involves use of remote sensing (satellite imaging) to measure pasture
cover and predict pasture growth. Research has been undertaken in this field
across Australia over a period of five years. Other technologies include an
infrared test that allows the quality of different hays to be measured, to help
farmers determine how much an animal will eat. Pasture
cover (biomass) can be estimated by measuring the amount of green foliage that
appears in satellite images to a square kilometre scale. This information can
then be combined with meteorological information (that is, local rainfall and
temperature readings) for a particular region and calculated into per hectare
figures on a weekly basis. Studies undertaken by CSIRO Livestock Industries on
trial sites in the south-west of Western Australia indicate that the technology
developed to “read” satellite images for estimations of pasture biomass has
a 97 percent accuracy, when compared to on-ground measurements. No, although there
may be ways around this. One method is to use the next or previous days’ data,
or images may be taken from another satellite. The satellite images are used in
combination with other data not constrained by cloud cover, such as rainfall and
temperature readings. The satellites
orbit 740 kilometres above Earth. They travel at the speed of Earth’s
rotation. Depends on the
specific satellite, some pass overhead daily, while others could be between 3
and 16 days apart. The satellites
provide images of green foliage (biomass) in pastures. iFarm has developed
software to assess the amount of biomass available by measuring the various
levels (or ‘greenness’) of biomass. This information is combined with
on-the-ground pasture and meteorological (rainfall, temperatures) data to
produce a kilogram per hectare figure for targeted regions. The satellite
assessments of pasture cover can be used to predict how quickly pastures are
growing. Satellite images
can be as detailed as one square kilometre, however, satellite assessments
should be interpreted in terms of a farmer’s own local knowledge and
experience. The pastures from
space technology has been trailed predominantly in the Mediterranean climate
zone of Australia, although the technology could feasibly be used in other
climate zones. Australia:
WA -
100+ sites (mostly participating farms)
NSW –
3 sites near Harden
Vic -
1 site near Hamilton
SA -
3 sites near Naracoorte and Goolera. New Zealand:
Waikato (under development)
While not
currently being undertaken by the consortium, other satellite technologies being
developed as precision agricultural management techniques for farmers include
tracking movement of livestock. Global Positioning Systems (GPS), used in
automobiles to obtain directions, is being used at the US Department of
Agriculture’s (USDA) Oregon Agricultural Research Centre. Agricultural
Research Service rangeland scientist Dave Ganskopp has installed collars with
special radio receivers on a dozen cattle. These receivers collect information
from a constellation of 24-30 satellites that may be working at any one time.
Using satellite coordinates, researchers can determine within a few metres where
a cow was and what time she was there. The GPS units track when cattle roam and
also monitor the animals’ head movements, which indicate whether the animals
are eating, sleeping or just walking. More details at: http://www.ars/usda.gov/is/pr/2002/020812.htm [Top] |
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