Evaluation of terrestrial laser scanners for measuring vegetation structure

[摘要] This work has evaluated data acquisition and processing requirements for current commercial time-of-flight and phase-shift terrestrial laser scanners in a forest environment. The instruments in the trial included a FARO Focus 3D 120, Leica C10, Leica HDS7000 and Riegl VZ1000. Scans and supporting standard forest inventory measurements were recorded in the D’Aguilar National Park at a site known as Landers Hut 3 (SITIA plot code: gold0101) on the 8th and 9th of November 2011.Key findings from the trial on practical use of commercial scanners for analysis of gap probability include:The complete set of measurements required for analysis of gap probability is not directly available from any of the scanners except the Leica C10. In the case of the two phase based instruments (FARO Focus 3D and Leica HDS7000), filtering needs to be performed in order to distinguish gaps in the canopy from multiple beam interceptions, both of which are recorded as no-data under standard processing methodologies. In the case of the Riegl VZ1000, there is no export file format that will maintain links between multiple returns from the one pulse. However, access to the Riegl software development library RiVLib does provide a low-level programmable interface to this required information.Hardware and/or software filtering options provided for the phase-shift scanners are sub-optimal for vegetation. Alternative filtering methods were developed that may be improved with further research by including all available information about the point (texture, range, intensity).Optimal use of the Riegl instrument would require a tilt mount in order to scan the entire upper hemisphere due to its limited field of view (30 to 130 degrees zenith angle). This tilt mount was not available for the trial and its practical application has not been considered in the analysis.

[发布日期] 2012-06-04 [发布机构] CSIRO

[学科分类] 地球科学(综合)