d. Oceans 



Oceans requirements are similar in nature to those of the 

 Ice Team. Operationally, at least daily coverage is 

 necessary over a 370-km swatch extending outwards from all 

 coasts. Global coverage is required on a 1 to 5 day 

 revisit cycle to assist in forecasting weather and ocean 

 conditions. 



e. Discussion 



The large northern area coverage and short revisit cycle 

 specified by the Ice Team will be the dominant factors in 

 determining the swath width, revisit cycles, and area 

 cover for the satellite. A satellite SAR having a 200-km 

 swath width and fixed antenna can very nearly meet 

 northern requirements, but east coast shipping routes 

 below 72° latitude cannot be adequately monitored by a 

 single satellite. In this mode, coverage of Renewable 

 Land Resources priority areas will also vary from 7 to 14 

 days and the operational requirements of the oceans group 

 cannot be met. A +^5° steerable antenna will ensure that 

 all northern areas of interest are covered within the 

 desirable revisit interval. With judicious programming of 

 the antenna incidence angle, most northern, east coast 

 shipping routes will receive adequate coverage even if the 

 swath width is reduced to 150 km. Renewable Land 

 Resources requirements for specific area cover during 

 dynamic growth cycles, infestations, or disasters could 

 also be largely met by the steerable antenna. The system 

 could be used to advantage in monitoring specific 

 operational areas at lower latitudes to meet the oceans 

 requirement. Global coverage with a minimum 5-day revisit 

 cycle (for ice or oceans scientific studies) cannot be met 

 with a single satellite regardless of antenna 

 configuration. However, the steerable antenna will, in 

 many instances, permit coverage of storm centres or other 

 phenomena that would not normally be accessible with a 

 fixed antenna system. A +_5° steerable antenna at a swath 

 width of 150 km is therefore considered to be the optimal 

 configuration. A minimum fixed antenna swath width of 200 

 km will be only just acceptable to meet major 

 requirements; 180 km is considered as marginally 

 acceptable. 



Spatial Resolution 



Requirements for spatial resolution stated by applications teams 

 are summarized as follows: 



5-11 



