Estimating the speed and motion direction of targets using a model of the turtle retina

In this paper we show how the velocity of a moving target across the visual field can be estimated using model of a turtle retina. The model of the retinal cells is the same as obtained earlier by the authors. Using the model, we show that the motion direction and the speed, of a target moving along a straight line, with constant speed, can be estimated in two steps. The speed can be estimated independently of the angle of the optical flow induced by the target motion. Using the speed, the retinal (model) response can be rescaled and the angle of optical flow (hence of the motion direction of the target) can be estimated independently of the speed.