Efficient Representation of Reflecting Structures For

A physically-based simulation model f o r a sonar navigation s y s t e m i s d e s c r i b e d , i n which t h e r e f l e c t i n g e l e m e n t s c o n s i s t o f w a l l s , c o r n e r s and edges arranged i n a floor plan. When t h e transducer is o p e r a t i n g i n t h e p u l s e l e c h o mode, e a c h e l e m e n t t h a t f a l l s i n t h e t r a n s d u c e r f i e l do f-v i e w c o n t r i b u t e s t o t h e r e f l e c t e d s i g n a l through i t s impulse response. The f l o o r p l a n i s represented as a two-dimensional grid of visibels, t h a t i n d i c a t e which elements are visible from a p a r t i c u l a r l o c a t i o n. A v i s i b e l i s represented by a word i n computer memory, e a c h b i t o f which i s a s s i g n e d t o a particular element (corner, wall o r edge) i n t h e f l o o r p l a n. The advantage of this conceptually simple approach i s t h a t i t allows the t r a n s d u c e r t o move t h r o u g h t h e f l o o r p l a n e f f i-c i e n t l y. T h i s e f f i c i e n c y r e s u l t s b e c a u s e t h …