5.3 LiDAR surveying
AAM was engaged by Venture Minerals to conduct a LiDAR survey over much of the Mt.
Lindsay Project area including part of EL24/2008. The Airborne Laser Scanning (ALS) data
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was acquired from a fixed wing aircraft on April 5th and April 6th 2011. GPS base station
support was acquired by Tritech Professional Services using an Optech ALTM Gemini 70
kHz Static RTK system. This allowed an assessment of the accuracy of the ALS data.
Reduction of the ALS data proceeded without any significant problems. Laser strikes were
classified into ground and non-ground points using a single algorithm across the project
area. Manual checking and editing of the data classification further improved the quality of
the terrain model. The Datum Projection Geoid Model was GDA94 MGA Zone 55 and
Ausgeoid98, and Primary Reference Station WCP1 357205.518, E 5380864.729 N,
268.738 RL. Project specifications and technical processes were designed to achieve
vertical data accuracy of 0.30 m and horizontal <0.30 m (1/5500 flying height). Ground
definition in vegetated terrain may contain localized areas with systematic errors or outliers
which fall outside this accuracy estimate. Laser strikes have been classified into “ground”
and “non-ground”, based upon algorithms tailored for major terrain/vegetation combinations
existing in the project area. The definition of the ground may be less accurate in isolated
pockets of dissimilar terrain/vegetation combinations. Ground data in this volume was
compared to 231 test points obtained by field survey on clear ground and assumed to be
error-free, achieving a mean difference of -0.250 m, standard deviation of 0.041 m and
RMS 0.254 m. The thinned laser strikes classified as “ground” for EL33/2007 are supplied
in Appendix D.