STUDY AREA AND GROUND TRUTH
The study area which was selected for agricultural
related studies was of approximately 5x5 km? The test
area (Kundal test site) is located in southwestern .
direction of Ahmedabad City in Gujarat State. The test
area was relatively flat with sandy loam as major type
of soil. The majority of land was used for crop production
although other land use categories like built up area,
natural Vegetation, Waterbodies were also present. The
soll samples collected in different fields during data
acquisition nhase showed similiarity of soil moisture for
major crops. Ihe wheat fields were of 10 to 15 em high
with similiar densities (40 plants per meter) and row
spacing (40cm). The row directions were mainly in two
directions i.e. North East and South Bast. The spacing
between each row was 40cm. The other fields were stubble
fields, Sorghum, irrigated bare field,high dry grass land
and ploughed fields. A detailed land use map of test site
was prepared during acquisition phase which is depicted
in Figure 1 along with legends.
SLAR DATA
LAND USE MAP |
KUNDAL AREA
The digital-data over the test area was collected by
DFVLR-SLAR system operating at 9.555 GHZ. One of the images
obtained over test area for a flight track at 40” from
north in NE direction is shoyn in Figure 2. The image
represents an area of 4x6 km“ on ground. The swath of SLAR-
System is 6 km at an altitude of one kilometer and
depression angle varies from 53 degrees to 8 degrees. The
numbers in the Figure 2 such as 1A, 1B, 23 etc. represent 4 \
different type of field and locations. ©
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METHODOLOGY X
The digital data was displayed on a TV monitor using A
DISIAS image processing system which has facility of image
data enlargement and reduction to desired scale. Ihe land
use categories were delineated and a window on SLAR image
equivalent to actual field size was cut using the DISIAS
System. The land use categories were selected on following
asiss
(a) The fields at same look angle with respect to radar
so that effect of radiometric errors and look angle
can eo Pici ptr ipd On this basis following fields were
selected:
14,0 18,:8 Stubble field
250 6,117 Wheat (NE-row direction)
3,153,505 Wheat (SE-row direction)
^ grass
(b) For the study of the influence of look angle and the
errors due to radiometry following fields (mixed row
directions) were selected :
9 to 23 Wheat (mixed row direction)
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