Uncertainty spatial information representation is a critical problem in qualitative spatial reasoning (QSR) and other spatial information process domains. Bittner put forward the rough location method which is better than other uncertainty spatial theories in special circumstance. But his theory wasn't formalized by relation algebra

thus can not be directly applied to spatial database or other spatial information applications. Based on rough set theory

we put forward a relation algebraic formalization for the rough location model and applied it to geographical informational system. Extending the RCC theory of QSR

basic spatial relation is defined by spatial relation matrix. Based on 249 basic relations and the operations on them the approximate spatial relation algebra ASRA is formed. After discussed its character and axiom

we studied the uncertainty of the maping from ASRA to RCC5. Applied it to GIS

a spatial relation judgement algorithm is given. Comparing with similar algorithms

it supports both crisp and approximate regions and is more efficient.