Preferable methods of mapping would require neither an extensive ground-control survey, nor target density that would demand a great deal of access. The goal was to identify a method that would not require a great deal of access to private property and would allow a shorter period for data collection to final product delivery. Integrated with differential kinematic GPS positioning, airborne scanning LiDAR is capable of providing sufficient information for two-foot contour mapping with minimal ground control and minimal time from data collection to product delivery. These coordinates can be directly input to most contouring software packages without the need for stereo modeling of photographs, saving valuable time. Another advantage is that because kinematic GPS is utilized, there is minimal need for ground control to reference the laser points to a horizontal or vertical datum.
Control can consist of existing monumentation with public access along a corridor.
Alternatively, control can be established in easily accessed areas because geometry of the control network is not nearly as critical as in the photogrammetric processes. The unobtrusive nature of airborne laser mapping with kinematic GPS made it an attractive option for the data capture needed to design this project. In order to establish these differences, the integer number of cycles between the receivers and satellites must be established. With original kinematic techniques, this is accomplished by using a variation of a static baseline initialization. Because of this, kinematic is impractical for collecting 3-D offset data while in motion because of the risk of not maintaining continuous tracking with the two receivers.