In LiDAR systems, the terms monostatic and bistatic refer to the configuration of the transmitter and receiver apertures. In a monostatic LiDAR, the same aperture is used for both transmitting and receiving signals. This requires careful isolation to prevent the transmitted pulse from interfering with the receiver. If proper isolation is not provided, backscatter from the transmitted pulse can blind the receiver.
On the other hand, bistatic LiDAR uses separate apertures for transmission and reception, allowing for the elimination of backscatter in the optical system. In this setup, the only backscatter concern arises from aerosols near the LiDAR. The transmit and receive apertures don’t have to be the same size or in the same place. This is advantageous for applications where different aperture sizes for illumination and reception are beneficial, such as flash LiDAR, where a small transmit aperture is needed to maintain phase coherence across the illuminated area.
Monostatic LiDAR is often chosen for its simplicity and space-saving benefits, as it does not require a second aperture. However, bistatic LiDAR can provide flexibility in designing systems that require separate transmit and receive paths, especially in multiple-input, multiple-output (MIMO) LiDAR systems, which use more than one transmitter and receiver.
