Block diagram of a BIPAR receiver 
Fig. 2: 
and 
x H^. 
34 Og = “I (4) 
where 6, and 8; are the spatial resolution in azimuth and elevation and o op i5 
the normalized bistatic scatter coefficient. 
The resulting equation for the received power of a BIPAR system indicates, that 
this power is moreless independent from the BIPAR pencil beam antenna dimen- 
sions and the aircraft flight altitude. 
Pp ? zi p A? Gi o ob oh (5) 
This is due to the fact that changes in flight altitude and in antenna beam- 
width implying loss and gain variations are compensated by resolution cell 
variations being consequently a result of the above changes. 
3.2 Spatial Performance | 
  
  
AIRCRAFT (VELOCITY - VA) 
  
  
  
BIPAR ANTENNA 
— DIMENSIONS: La, Le 
— BEAMWIDTH: en © 
     
JAN 
LAN 
fra 
/, lu N 
li Ww 
1E d 5 
ALTITUDE H 
ia 
"SS 
Ss 
N 
N 
RESOLUTION CELL 0A x og 
  
Ha SWATH WIDTH W +: 
  
Np = NUMBER OF PIXELS IN ELEVATION (INTEGER) 
N, = NUMBER OF INDEPENDENT LOOKS 
Fig. 3: BIPAR Scan Geometry 
49