Rob Wooding & Associates

Aerial Survey Consultants

Lidar

There is some truth in the claim that these days there is nothing that can be done with lidar that can not also be done by photogrammetry.  This was not always the case but the new generations of photogrammetric software will deliver point clouds that are comparable to lidar.  However, in most situations photogrammetry cannot come close to lidar for speed of delivery, it cannot match the vegetation penetration properties of lidar and it cannot achieve the accuracy of lidar unless flown very low, which in turn means a lot more work.  This does not mean lidar is more suitable in every instance.  It is very expensive equipment and therefore carrys a price penalty of it's own but it is an essential tool for modern aerial survey.

Starting initially with a modest Riegl 280 lidar, in 2013 the firm upgraded to a state of the art unit that provides a 400khz, full wave form output and a 1,700 meter range.   The lidar is always flown in conjunction with a 65mp photogrammetric camera so that pin sharp orthophotos are a guaranteed by product.

In addition, for quality control purposes, the firm has a MDL 12khz laser profile meter with a 700 meter range.  Acquired in order to check both photogrammetric and lidar generated digital terrain models, it produces a very dense single line of points across a site, typically a few centimeters apart.  By flying a few discrete lines, tangential to the original survey, it is possible to quickly and cheaply achieve a thorough and complete quality check in a way that no form of ground survey can ever hope to match.