present evidence that will cause them to revise their present concepts. 

 Continued revision of the mission requirements as presented, and further 

 dialogue with members of mission concept and SAR design teams, will 

 therefore be mandatory as the program proceeds. 



B. It is a relatively simple task for each user, within his area of 

 interest, to define his requirements as he perceives SAR application to 

 his problems. Unfortunately, in a program such as RADARSAT, a user's 

 ideal requirements may be difficult or impossible to meet due to 

 technical or operational constraints. Through discussions with 

 engineering and other design authorities, applications study teams have 

 been made aware of foreseeable constraints and anticipated possible 

 tradeoffs. The study teams' reports reflect their attempts to stay 

 within technical and operational guidelines established. Flexibility 

 has been maintained whenever possible by categorizing requirements as 

 optimal, acceptable, or marginal. Teams have attempted in all cases to 

 specify requirements in known and acceptable engineering terms, e.g., 

 the SAR signal response should be consistent to within +.0.25 dB in a 

 given scene. 



C. MISSION REQUIREMENTS CORRELATION 



It is obvious that a fixed set of satellite and radar parameters will 

 not satisfy the requirements of all applications teams, or even all of 

 the various applications within any one team's area of responsibility. 

 Within imposed technical and operational limits, teams have reached a 

 consensus on the most acceptable requirement compromise which retains 

 essential usefulness of SAR within their area. Value judgments on which 

 their choices are based are detailed in each report. No attempt has 

 been made in this section to justify parameters presented; they are 

 listed in Tables 5 to 9 inclusive, under specific headings, to highlight 

 commonalities in applications requirements. This permitted the 

 selection, categorization, and presentation in Table 9 of the sets of 

 parameters most likely to meet the greatest number of requirements. 



D. RATIONALIZATION 



This section outlines the rationale on which parameter selection was 

 based. 



1. Frequency and Incidence Angles 



In accordance with established Canadian baseline restraints, only 

 two frequencies, C-band at 5.3 GHz, 6-cm wavelength, and L-band at 

 1 GHz, 23-cm wavelength have been considered. In all cases, 

 incidence angle is measured from nadir to the center ray of the 

 radar transmit beam. Frequency and incidence angle are so closely 

 interrelated that they are discussed jointly. 



Requirements for frequency and incidence angle stated by 

 applications teams are summarized as follows: 



5-2 



