The point cloud is a representation of the terrain in the form of measurement points with XYZ coordinates and are obtained on the basis of laser scanning, aerial photos and digitization of topographic maps.
Measurement Data is made available in digital form in the following formats:
LAZ*
Binary files containing point clouds from airborne laser scanning (LIDAR), saved in accordance with the 1.2 standard published in 2008 by ASPRS (American Society for Photogrammetry and Remote Sensing).
In addition to coordinates, these files contain, among others: information about the class of a given point and the intensity of reflection in three ranges of the visible part of electromagnetic radiation, corresponding to blue, green and red colors (RGB values), obtained from aerial photos.
Point classes were separated in accordance with the LAS format:
0. points processed but not classified,
2. points lying on the ground,
3. points representing low vegetation, i.e. in the range of 0-0.40 m,
4. points representing average vegetation, i.e. in the range of 0.40-2.00 m,
5. points representing high vegetation, i.e. above 2.00 m,
6. points representing buildings, structures and engineering structures;
7. noise,
9. points representing water areas
12. points from multiple coverage areas.
The correctness of point classification is not less than 95%.
ACCESS TO DATA – ONLINE
Service of downloading measurement data from the website www.geoportal.gov.pl
A service for downloading measurement data is available on the website www.geoportal.gov.pl, which allows you to download measurement data available in czgik.
*Data from the LAS format is compressed to the LAZ format, which reduces its volume to approximately 7-20% of its original size, while retaining every single bit - this is lossless compression. Data between LAZ and LAS formats can be converted using the free LASZIP tools (https://laszip.org/). Additionally, the compressed data in the Description attribute (always in the first Variable Length Record) contains metadata in the following structure: "GUGIK/flight date/measurement data density/situational accuracy [cm]/altitude accuracy [cm]