  Automated vehicles (AV) heavily depend on robust perception systems. Current
methods for evaluating vision systems focus mainly on frame-by-frame
performance. Such evaluation methods appear to be inadequate in assessing the
performance of a perception subsystem when used within an AV. In this paper, we
present a logic -- referred to as Spatio-Temporal Perception Logic (STPL) --
which utilizes both spatial and temporal modalities. STPL enables reasoning
over perception data using spatial and temporal operators. One major advantage
of STPL is that it facilitates basic sanity checks on the functional
performance of the perception system, even without ground-truth data in some
cases. We identify a fragment of STPL which is efficiently monitorable offline
in polynomial time. Finally, we present a range of specifications for AV
perception systems to highlight the types of requirements that can be expressed
and analyzed through offline monitoring with STPL.
