LiDAR Topographic Survey

Using state of the art technology, our LiDAR equipment is capable of getting accurate topographic data, even in places where vegetation obscures the ground, such as in forests, plantations. Our system can easily get up to 500 points per square meter raw point density. By employing field-proven Phoenix AL3-32 LiDAR system, we are capable of getting precise topographic data even in terrain obscured by vegetation. The result is topographic map scale 1:500.

To ensure data accuracy, we will establish a network of temporary ground control points with accuracy better than 1 cm to be established within the project area and distributed evenly. Ground Control Points are required to achieve the expected accuracy of the project. TOP Aerial will set up a geodetic GPS base station located within the project area. This GPS base station serves as the reference and satellite correction station for the kinematic data post-processing and analysis.


Principles of LiDAR survey

Laser measurement penetration through vegetation to the ground will depend upon the vegetation density. However, steps will be taken to maximize the number of points reaching the ground. Laser strikes will be classified into “ground” and “non-ground” based upon a general classification algorithm tailored for the project area as a whole. Data classification will be manually checked and edited against the captured digital imagery.

Vegetation penetration by LiDAR pulses