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. © 
$* . 
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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