Use of Laser Rangefinders in Forestry
Data collection is applied in forest resource inventory, including tree height measurement, merchantable timber height, vegetation mapping, positioning of rare wild tree species and superior tree varieties, grading trees and assessing their economic value within an area. For cultivation management research such as pruning, it is used to locate trees at specified heights, plot timber volume profiles and define resource boundaries. When considering methods for stacked timber during log harvesting, it plays an important role in topographic surveying and mapping of access routes for piled timber, as well as pre-construction surveys for general-purpose roads and rugged trails. Conventional surveys, aerial photography and GPS positioning used in the past may encounter various issues (e.g., cost, accuracy, obstacles, etc.).
Field data collection has long troubled surveyors, cartographers, GIS database administrators, engineers and researchers. The core challenge is straightforward: how to efficiently and accurately collect positional and physical feature data for mapping, inventory compilation, resource assessment and database storage.
Finding a solution to this problem under given conditions can be troublesome for two reasons: (1) A wide range of methods and technologies may be available; (2) In most cases, no single method can independently deliver complete and satisfactory results.
The application of laser technology, especially laser rangefinders developed by Laser Technology, Inc. (LTI) of the United States, has matured progressively since 1990. In that year, the USDA Forest Service evaluated these devices as field measurement prototypes for future application. The rangefinders can connect to data collectors and GPS units, and support a rich variety of software configurations. This advancement has transformed forest surveying from manual tools such as compasses, measuring tapes, clinometers and old telescopes into an era of single-operator, total-station, fully integrated multi-purpose instruments.
