In an arithmetic operation system, an evaluation unit calculates a difference amount between a teaching signal and an estimated signal. The teaching signal has a value that is obtained by integrating spatial distribution signals observed by a sensor using emission waves for a spatial structure along a region of interest in an emission wave region in which emission waves are emitted from a plurality of emission reference directions and reach the sensor. The region of interest is a curved line region or a curved surface region intersecting the plurality of emission reference directions. This estimated signal is calculated by integrating a plurality of pieces of estimated density of a plurality of sample points obtained from a spatial estimation model by having a sampling unit input information about a position of each of the plurality of sample points on the region of interest to the spatial estimation model.