Array Signal Processing: What are snapshots in Direction of Arrival estimation?
A snapshot is simply a data capture (sample window) of ADC samples from all receivers, that we know holds all the information to resolve what we need (distance and/or direction) given the various dimensions involved (transmit pulse length, nearest possible target distance, farthest possible distance, maximum array dimension, and the echo wavelet length). This defines the delay (from start of transmit time) of the window and the length of the window. The literature refers to a "snapshot" because many systems can repeatedly take snapshots to integrate-out noise, etc., but other cheaper systems can't.