LiDAR which stands for ‘Light Detection And Ranging’ is a remote sensing & surveying technology that measures distance by illuminating a target with a pulsed laser light. These light pulses combined with other data recorded by suitable Mapping systems generate precise, three-dimensional information about the shape of the Earth and its surface characteristics. LiDAR mapping, sometimes referred to as ‘3D laser scanning’ is popularly used as a technology to make high-resolution maps, with applications in geodesy/ geomatics, with terrestrial, airborne & mobile mapping methods.
Mobile LiDAR is an advanced mapping solution that incorporates the most advanced LiDAR sensors, cameras and position/navigation/DGPS/GNSS receivers to collect survey grade 3D point cloud data quickly and accurately.
Survey Grade Mobile LiDAR mapping is the process of collecting geospatial data from a mobile vehicle, typically fitted with a LiDAR remote sensing system. Such systems are composed of an integrated array of time synchronized navigation sensors (survey grade DGPS/GNSS) and imaging sensors mounted on a mobile platform. The primary output after pre-processing from such systems include; geo-referenced 3D point cloud data, digital maps, images and videos. The overall accuracy of the data which can be easily achieved is about +/- 2 cm.
Screenshot of 3D Scan point cloud data of an urban street in ‘Leica Map Factory’
“Prashant Surveys” is the first company in India to procure “Leica Pegasus One” 3D Mobile LiDAR Survey & mapping System in March 2015. It is also the 1st Land Surveying company in India to possess 2 numbers of ‘Leica Pegasus Two’ Mobile LiDAR Systems in the year 2017. “Prashant Surveys” has the capacity to capture LiDAR data of highways for about 200 Kilometers per day using two instruments, with accuracy of about +/- 2 cm. The Pegasus system captures dense 3D point cloud data with calibrated imagery and enables processing, visualization and mapping through user-friendly software platform “Leica Auto PP & Leica Map Factory Advanced”. It provides plug-and-play hardware including cameras and LiDAR sensors, enabled by a software solution to control data acquisition, calibration, post-processing, viewing, editing and storage modules.
Mobile mapping allows rapid collection of all visible assets from a moving vehicle driving at posted speeds. This cutting-edge Mobile LiDAR technology provides a rich, high-density dataset that measures about one million 3D points per second. This Leica Pegasus system gives a unique & complete Survey grade mobile mapping solution to our clients with high speed & accuracy. The system can be mounted on any four-wheeler vehicle & can capture high precise data upto +/- 2 cm for about 100 Km of Highways in one day, which would have taken at least a month using primitive Electronic Total Stations (ETS) method.
3D Mobile LiDAR Survey using ‘Leica Pegasus Two’ system
Screenshot of sample output file for highway corridor, in 'Leica Map Factory'
Brief facts on high Speed LiDAR Data Capture using Mobile LiDAR 'Leica Pegasus Two'
- Mobile LiDAR Data can be collected with the speed of vehicle varying from 10 Km / hour (on city roads) up to 80 Km / hour (on Highways). Ideal vehicle speed maintained by us is usually 30 to 40 Km / hour on city roads and 40 to 50 Km / hour on Highways.
- Each run of Mobile LiDAR can easily capture about 150 m corridor (i.e. 75 m on either side of the run) with dense 3D point cloud data, 360 degrees panoramic view camera data and GNSS / IMU data. Multiple runs are usually required for capturing high quality 3D point cloud data on Highways and Expressways with median, grade separators and service roads.
- In one day, about 70 Km to 100 Km length Mobile LiDAR data can be easily collected by 'Leica Pegasus Two' on a two-lane highway with single run.
- The raw data collected on site is so dense (about 1 GB data collected for 1 Km length of highway) that it has to be downloaded into external hard disk and transported to the head office for further data processing and feature extraction, from the registered 3D point cloud data.
- LiDAR data processing and registration on 3D point cloud is done using 'Leica Auto Process' software, whereas the feature extraction of point, line and polygon features are done using multiple licenses of Leica Map factory software. Final delivery of 3D topographic plan can be made in Arc GIS shape files or Autocad Dwg files as per the requirements of the client.
Screenshot of sample output file for highway corridor, in 'Leica Map Factory'
Our Initiative in the Mobile LiDAR Technology
- We are the 1st company in India to procure LEICA ‘Pegasus One’ Survey Grade, Mobile LiDAR System in March 2015.
- We are the 1st Land Surveying company in India to possess 2 numbers of ‘Leica Pegasus Two’ Mobile LiDAR Systems in the year 2017.
- Have successfully completed more than 12,000 chainage Kms of highway surveys throughout India using 3D Mobile LiDAR & NSV (Network Survey Vehicle) technology since year 2015.
- Mr. Prashant Alatgi, Head : Technical & Business Development of ‘Prashant Surveys’, was a speaker on ‘Mobile LiDAR Technology’ in 14 International Conferences worldwide. (Please click here to view Events & Conferences).
Advantages of using Mobile LiDAR over Conventional Total Stations
- Field data capture can be done with great speed which gathers all required data point measurements in one pass, eliminating the need for additional mobilization costs.
- Mobile LiDAR gives the ability to collect up to 1 million points per second, compared to one point every few minutes with traditional Total Station survey technology, which save lots of time in field.
- Data Capture using mobile LiDAR is very efficient in sensitive areas or areas with extreme harsh climates.
- The captured data gives complete information about the site, with accurate point measurements and the ability to locate features that may be inaccessible with other methods.
- The data captured once can be used for different applications afterwards.
- Collected Pictures and images can be used to generate videos which can assist in decision making in the office, thereby reducing the frequency of site visits.
- Manpower required is considerably less, which adds to the savings in the overall project costs.
- Lesser chances of human error, process is more automated.
- The accuracy obtained is absolute, depending on the GPS and is not compounding in nature.
- Provides increased safety for project personnel and the general public because data can be collected remotely, removing the need for traffic diversion.
Limitations of mobile LiDAR mapping system
- System cannot be used in poor visibility due to rainfall, fog, snow etc. and requires direct line of site visibility while capturing the data.
- Not suitable for use in terrain without access / motor able roads.
- Raw data captured is large in size (about 80 GB for 100 Km road, with single run).
- Requires huge investments for hardwares, softwares and skilled manpower especially for ‘3d point cloud’ data processing work.
For further detailed information on Mobile Lidar Survey, you can download our brochure from the "Download : Corporate Brochure" link.