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AN INTEGRATED PACKAGE FOR THE PROCESSING 
AND ANALYSIS OF SAR IMAGERY, AND THE FUSION OF 
RADAR AND PASSIVE MICROWAVE DATA 
Bernard Armour, Jim Ehrismann, Frank Chen, Gord Bowman 
Elena Berestesky, David Adams, Andrew Emmons 
Atlantis Scientific Systems Group Inc., 
1827 Woodward Drive, Ottawa, Ontario, Canada, K2C 0P9 
Julius Princz 
Canada Centre for Remote Sensing, Special Technology Division, National Resources Canada 
588 Booth Street, Ottawa Ontario, Canada, K1A 0E9 
René O. Ramseier 
Atmospheric Environment Service, Ice Operations and Research Group, 
P.O. Boz 100, 195 Westbrook Road, Stittsville, Ontario, Canada, K2S 1A2 
ABSTRACT 
FarthView SAR Application Package or EV-SAR is an integrated software package designed for the processing, 
analysis, and fusion of Synthetic Aperture Radar (SAR) data. The development to date has resulted in software 
that performs many functions with SAR imagery ranging from image quality measurement analysis to fusion 
of SAR imagery with other data sets. These include SAR image radiometric and geometric corrections, SAR 
image enhancement filters, SAR image display and measurement techniques, polarimetric SAR functions, and 
multisensor data fusion. New users of SAR imagery have found the package to be useful as a tutorial on 
understanding SAR remote sensing and as an introduction to SAR processing and data manipulation. Expert 
users have found EV-SAR to be a useful tool for working with SAR data. 
KEY WORDS: Image Processing, Synthetic Aperture Radar, Geocoding, Data Fusion, Remote Sensing 
1. INTRODUCTION 
This paper describes the commands developed as part 
of the EarthView Synthetic Aperture Radar package 
or EV-SAR. EarthView is a general image process- 
ing package for PC 386/486/Pentium computers. It 
is used in many applications where variable image size, 
large dynamic range, and multiple data types (inte- 
ger, floating point, complex) are required. EV-SAR is 
an application package built using existing commands 
in the EarthView command library plus a set of new 
commands functions written specifically for processing 
Synthetic Aperture Radar (SAR) imagery. Since the 
SAR sensor has a point target response which extends 
in two dimensions with a predictable sidelobe struc- 
ture, and since SAR is susceptible to multiplicative 
noise as well as the usual additive noise, special pro- 
cessing tools taking into account these characteristics 
will aid interpretation. Several of these functions have 
been implemented in EV-SAR and are described in the 
following. 
The paper is organized as follows. In Section 2, SAR 
image corrections are described, followed by SAR im- 
age enhancement techniques in Section 3. In Section 4, 
SAR image display and measurement functions are de- 
scribed. In Section 5, the polarimetric SAR functions 
are introduced. In Section 6, some multisensor data 
fusion functions are described, followed by the conclu- 
sions in Section 7. 
2. SAR IMAGE CORRECTIONS 
2.1 Antenna Pattern Correction 
The variations in radar cross-section pattern, dis- 
tance and incidence angle along a range line may cause 
severely uneven power distribution in the SAR image. 
The EV-SAR antenna pattern correction functions are 
designed to remove this effect. 
The antenna pattern is estimated by averaging lines 
of constant azimuth to extract a mean range profile. 
The extraction of the antenna pattern can be done 
either by low pass filtering the profile or by fitting 
the profile to a polynomial curve. Both operations 
use standard EarthView commands. This approach 
is based on the fundamental assumption that the 
scattering properties of the area of interest are stable, 
or the variation is well characterized so that the 
extraction of the profile is of practical significance. The 
effectiveness of this algorithm is demonstrated in the 
example of Figure 1. 
2.2 Geometric Transformations 
When studying SAR imagery, it is in many instances 
necessary to transform a SAR image in slant range to 
ground range, and vice versa. EarthView employs a 
collection of functions for such geometric transforma- 
tions for both airborne and spaceborne SAR imagery, 
assuming flat and spherical Earth models, respectively. 
In the airborne case, input parameters are altitude, 
stand off distance and range sample spacing; in the 
spaceborne case, input parameters are altitude, sur- 
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