Integration Of Laser Rangefinder And Multispectral Video Data For Forest Measurements

Attempts to improve the accuracy and timeliness of forest measurements have led to the applica­ tion of new sensor technologies which collect high resolution digital data sets from an airborne configuration. Two devices which have shown particular promise are the laser rangefinder and the multispectral video camera. These instruments are capable of measuring a number of primary forest Parameters, including tree height, accurately and economically. Used in an integrated sensor package, they can generate three dimensional views of the forest body and underlying terrain; however, the data sets collected are large, with a high level of complexity. The objective of the work described herein was to develop a system for extracting forest information from simultaneously acquired coinci­ dent laser and video data. Test data sets were acquired over an area in west central Alberta and consisted of multiple low level flight lines over a variety of forest cover types. An integrated sensor package was used, consisting of a high frequency laser rangefinder and a six band multispectral video ,camera. Extensive ground data were compiled and supplemented with historical data from permanent sample plots maintained by the Alberta Forest Service. This information was used to develop and test a system for filtering and correlating the remote­ ly sensed data in a semi-automatic manner. Analysis of the information derived showed a high degree of accuracy in the measurement of tree heights and stand densities, while species, crown diameters, and vigor could be estimated. Current research is aimed at the generalization of the software system to provide support for a wide variety of forest cover types as well as a direct and logical interface to forestry GIS systems.