iltitemporal air- 
due to random 
id position of 
the flight 
:ort the resul- 
e further multi- 
iffects influence 
enna; e.g. the 
ipression 
is dependent 
National Aero- 
oration with 
iry TNO, the 
he Survey 
to implement a 
he central 
icquired data 
rcraft motion 
■ recorded INS 
craft (INS = 
iry acquired 
rial 
is enabling 
data via an 
’ARES-procedure 
i corrections, 
may now be 
irther complica- 
on [Ref. 2, 3]. 
;e is a distur- 
id classifi- 
.cation algo- 
extraction pro 
in a pixel-by- 
-field basis, 
i have devised 
ild averaging. 
ien tried but The 
ir the "split- 
ivlidis-concept 
lage processing 
iace Laboratory 
irocess (in 
;es with a number 
linimum field 
r erages where 
aced by a field- 
information, 
ds which contain 
r to contaminate 
. objects like 
ilso corrupt the 
;ing the final 
leratively 
id classifier may 
isifier allows 
data space into 
.1 be obvious 
time-consuming 
te preceeding 
already greatly 
e pixel values, 
t is possible, 
int the angular 
.tural crops to 
in result. One 
irocess suffi- 
ilar dependence 
Table 1. Specifications SLAR data acquisition and 
registration chain. 
Antenna 2,5 m slotted wave guide 
Polarisation HH 
Pattern azimuth 16 mrad 
Elevation: cosec 2 -pattern (Ref. 2, 3) 
Transceiver Modified DECCA 65160 
Frequency 9,4 GHz (X-band) 
Transmitted power 25 kW 
Pulse length 50 (250)ns 
PRF 100 Hz (200 Hz) 
DC coupled IF amplifier and 
detection circuit 
type ICLT 6020 from RHG 
Output: GO-2 V 
23.7 mV/dB 
Dynamic range 80 dB 
SLARDIG Presample filter 3rd order 5MHz,(none) 
(SPEEDIG) Sample rate 20 MHz , (50 MHz) 
Start sampling jitter 0-5 ns, (same) 
2048 samples = 15 km range,(4096;12 km) 
8 bits/sample , (same) 
Input 0,01 ± 0,004 V; output 0, (same) 
Input 2,000 ± 0,004 V: (same) 
7,8 mV/bit , (same) 
Aircraft 
data for PARES the data of the Inertial 
Sensor System (ISS) 
Litton LTN58 are important: 
True Heading TH 
North South Velocity VNS 
East West Velocity VEW Digital outputs 
Latitude LAT 
Longitude LON 
Angle of roll AR1IS Synchro outputs 
Angle of pitch AP1IS Digitized by RMDU 
Accuracy:angles better than 0.1° 
velocity better than 1 m/s 
position better than 2 mile/hr 
TABLE 2. Classification-matric of Flevo-area (1984) 
58 
POTATOES 
58 
(100%) 
58 
SUGAR- 
BEETS 
1 
54 
(93%) 
3 
92 
WINTER- 
WHEAT 
3 
- 
89 
(97%) 
35 
ONIONS 
14 
4 
2 
9 
(25%) 
6 
9 
BEANS 
2 
1 
- 
6 
(66%) 
OTHER 
9 
3 
8 
7 DATA INTERPRETATION AND ANALYSIS 
A matrix of classification results compared to the 
ground truth map of the Flevo-test site from the 
1984 campaign is shown in [Table 2]. 
It is evident from this table that the small 
Fig. 1 The NLR Metro II Laboratory aircraft with 
SLAR antenna 
Fig. 2 Backscatter coefficient vs. time for three 
major crops 
APR 
1980 
° SUGARBEETS A POTATOES 
HH 
30 
HH 
30 
+ S.WHEAT 
HH 
30 
x OATS 
HH 
30 
<> B.SOIL2 
HH 
30 
Fig. 3 Backscatter coefficient vs. time