Lidar has become an exciting alternative to ground survey and photogrammetric techniques in mapping applications. Fixed wing aircraft Lidar has the ability to penetrate foliage and thus obtain a ground elevation model in forested areas. In the last two years, the amount of Lidar based Unmanned Aerial Vehicles (UAV) has been cutting into the UAV photogrammetric market. One needs to understand how survey grade kinematic GPS-IMU is used in conjunction with the Lidar to obtain survey grade accuracies. Ground based static Lidar is a mainstay of certain mapping applications. But mobile Lidar (ground vehicle mounted) with GPS-IMU is cutting into the static Lidar niche. The complications of resolving survey grade GPS-IMU in urban situations where GPS signal is random needs to be discussed and how much survey control may be required to resolve the issue.