Radar and LIDAR
Radar and LIDAR are each electronic devices used to measure the speed of moving objects. However, there are differences you need to be aware of.
Radar is absolutely accepted by the court as accurate as long as it has been properly maintained and calibrated and the officer is properly trained in its use. One limitation of Radar is that it will only clock the speed of the closest moving object. This means there were no cars between the radar unit and your car. This fact can be helpful when arguing the traffic part of a Basic Speed Law case.
While radar speed evidence is universally accepted as susceptible to judicial notice, laser evidence is derived from much newer technologies and does not yet have that status. A gentleman named Paul Gowder prepared an excellent bench memo on this. If you have a LIDAR ticket, you need to read the memo. An advantage of LIDAR for the prosecution is that it can pick a vehicle out of a whole group and is not limited to only the closest one. That is assumng it withstands the challenges set forth in the bench memo.
Both radar and LIDAR come under Vehicle Code 40803(b) which requires that the prosecution prove the case does not involve an illegal speed trap.