1:500 topographic mapping, this airborne LiDAR could help a lot

PM-1500 could help to increase the efficient productivity

I. Project Background

Topographic mapping is an important means to obtain location spatial information. In recent years, airborne LiDAR measurement technology is widely used in topographic survey because of its advantages of low cost, strong flexibility, high precision and high operation efficiency. Compared with traditional measurement, LiDAR can measure day and night, which can greatly improve the work efficiency; Multi echo technology penetrating vegetation can not only save manpower, but also reduce the error caused by human factors in traditional measurement, and has a broad application prospect.

II. Project Overview

The survey area is flat terrain with small topographic relief, and the maximum height drop is 20m. There is a main road in the area with dense vegetation and several densely populated residential areas.

III. Requirements and Difficulties

Accuracy requirement: 1) point density better than 16pt/m²;

                                     2) accuracy requirement: horizontal/vertical ≤5cm, meet 1:500 topographic mapping requirement.

Difficulties: 

1) The terrain is complex: the vegetation in the survey area is dense, and the accurate elevation data of the survey area can’t be obtained by the traditional survey method efficiently;

2) Task time is tight: it is required to complete the task of data acquisition and result output of the survey area in 3 days;

3) Difficult transition: the road condition of the survey area is complex, and the transition of traditional surveying and mapping equipment is time-consuming and laborious.

IV. Solution

PM-1500 airborne laser measurement system mounted on Longteng multi-rotor UAV platform is selected for this project.

System advantages:

1) 2M pts/sec ultra high point frequency;

2) 1500m ultra long measurement range;

3) 4times echo to feedback real landform;

4) Task operation could be controlled in real time on site.

Data results display:

When PM-1500 is mounted on UAV for operation, it can synchronously obtain the original point cloud data and original image data, which can provide a strong guarantee for the output of subsequent results.

V. Summary

Conventional measurement methods are time-consuming and labor-consuming, slow speed, high cost and low efficiency, and are greatly restricted by natural and geographical conditions. Airborne LiDAR mounted on UAV platform has the characteristics of flexibility, convenient use and simple maintenance. It will receive more and more attention in the field of 1:500 and 1:1000 surveying and mapping.

Advantages of PM-1500 airborne laser measurement system:

1) High accuracy: no ground control points required, the absolute mean square error of point cloud can be within 5cm, meeting the requirement of 1:500 mapping;

2) High efficiency: the endurance time is 40min, and 1.2km² of terrain/1okm of strip road ( two strips with a bandwidth of 300m) can be scanned in a single sortie operation;

3) Stereoscopic mapping: based on point cloud mapping software, including stereoscopic, vector, panoramic, 2.5D and other mapping modules, point, line and surface feature elements of point cloud data are collected and the elevation frame is selected, surface features could be drawn quickly.