A Prediction Model for Ship-Generated Intermodulations

The need f o r a c c u r a t e , f a s t , i n t e r f e r e n c e f r e e and r e l i a b l e communication systems i s e v e r i n c r e a s i n g . The uses o f e l e c t r o m a g n e t i c spectrum f o r a m ul t i tude o f purposes such as radar , n a v i g a t i o n , f i r e c o n t r o l , e l e c t r o n i c warfare and e l e c t r o n i c countermeasures impose se v e r e spectrum p o l l u t i o n problems. These pose p a r t i ­ c u l a r d i f f i c u l t i e s on l i m i t e d "real e s t a t e " systems such as naval v e s s e l s , a i r c r a f t and space v e h i c l e s . A l l . o f th e s e uses r eq u ire antennas which r a d i a t e and r e c e i v e e l e c t r o m a g n e t i c energy on l i m i t e d "real e s t a t e s . " T h is , in t u r n , causes s e v e r e e l e c t r o m a g n e t i c i n t e r f e r ­ ence problems. One such i n t e r f e r e n c e problem i s the n o n l i n e a r g e n e r a t e d in term o d ula t io n products (IMP).