Airborne laser scanning Airborne laser scanning
A detailed description of the data aqcuisition plans:
- Airborne laser scanning - are collections of points that are recorded by the device, which is named LIDAR (Light Detection and Ranging), placed on the board of aircraft. LIDAR sends a laser beam of light in very short periods of time and record the positions of their reflections from objects on the ground. Thanks to the system of gyroscopes and a GPS receiver, laser scan point cloud is georectified and the precision of measurements reaches 10-15 cm in all directions. The latest scanners send out even more than 300 000 laser beams per second. It makes possible measurements with a very large number of points. In the project, there is planned acquisition of point cloud’s density about 4-5 pts./m2. Such density allows analysis on the level of a single tree. The great advantage of laser scanning airborne data, unlike of the another photogrammetric technologies is their ability to penetrate the crown. Due to that, even in quite dense environment, some of the beams reaches the ground. That makes possible creation of accurate digital elevation models, accurate determination of the objects’ height and structural analysis of stans. Unfortunately, laser scanning data are still expensive, so there are planned 3 air-raids in the project.
- Hyperspectral Imagery - very high spectra resolution data – concerning from few dozen to several hundred of narrow spectra bands. Such data can be used to acquire precise information about the object of analysis, its characteristics, structure and composition. Hyperspectral data is especially useful in vegetation studies, because there are lots of factors influencing vegetation spectral reflectance. In this project, it will be also important to find an optimal term for airstrike’s execution.