Geographic Information System or GIS has played a major role in Geospatial technology to collate, manage, and analyze data. It is basically geographical science that provides the platform for multiple applications of GIS viz. Photogrammetry, LIDAR, Mapping, and more. GIS has a multitude of applications in various industry verticals like Urban planning, Environmental Analysis, Disaster Management, Navigation, and the comprehensive list continues…GIS education has picked up significant traction in terms of various GIS courses in India and Abroad. There is an influx seen by many individuals and professionals in India to enroll for career-based training for Geographic Information System(GIS). These training programs offer great career options wherein individuals can apply for positions for GIS analyst, GIS developer, GIS engineers, GIS technicians and more. One of the technologies that we are going to point out is Light Detection and Ranging (LIDAR). Like SONAR, that works on sound navigation, LIDAR works on the principle of Light, wherein a pulse of light energy hits the object and returns to the sensor generating a point cloud of millions of points in a single pulse.
Understanding the concept of LIDAR
LIDAR stands for Light Detection and Ranging(LIDAR). It is a remote sensing technology that uses laser pulses to measure ranges or a variable distance of the earth. When these light pulses are integrated with data from airborne sources, they tend to generate information in 3D, these are precise models that provide information about the shape of the earth. Instruments used in laser scanners are lasers, scanners, and a receiver that is equipped with Global Positioning System or GPS. A LIDAR can be used to map natural and man made environments and objects with precision, accuracy, and reliability. The outputs of a LIDAR include Number of Returns, Digital Elevation Models, Canopy Height Models, Point Classification, Predicting the energy yield for wind power, use of fertilizers for farming, navigation of autonomous vehicles, and more.
LIDAR – Geiger Mode LIDAR and Single Photon
The next evolution of LIDAR – Geiger Mode LIDAR and Single Photon technology
The next step in LIDAR evolution is Geiger-mode LIDAR and Single Photon LIDAR, that offers high altitude scans over a larger mapping area. These lasers require a low laser energy requirement, it provides technologists to map with very less photon density. With low energy requirements and high density mapping, this technology can be used for high altitude flying up to 30,000 feet, and acquire high density points of up to 25 points per square meter, this was limited to 5000-8000 feet in linear LIDAR or legacy Radar Systems. Not moving into greater technical details, the main difference of Linear vs Geiger-Mode and Single Photon is the laser color scheme, return capability with single photon, and solar noise sensitivity. Green lasers have an advantage over Geiger – mode as it can penetrate shallow water, whilst Geiger-mode cannot. In terms of solar noise, Geiger-Mode technology can be used for night flights as well.
Accurate Sensing
With less photon density, and higher density gain the accuracy of both these systems is very high in terms of producing dense and sharp point clouds regardless of time and environment. Several experiments conducted for vertical accuracy through these sensors revealed that both the sensors performed well for various areas of interest.
Solar Noise
Several experiments conducted with the Geiger-mode sensor showed very less variation in day and night performance. The sensor performed well at night, rather than day, but the values were infinitesimal. The overall quality of the sensor at the both the times was high quality.
Reflectivity
Many object reflect light, thus legacy sensors or linear sensors do not provide very sharp and precise images for reflective surfaces. In an experiment conducted with both these LIDARS provided an accuracy of 15-50cm combined for the Single-Photon Radar and Geiger Mode LIDAR.
Closing lines
So, does this mean Single Photon LIDARS and Geiger-Mode LIDARS would replace Linear LIDAR technology? The answer to this varies with applications. Each of these devices may perform differently under different circumstances. There’s a lot of development happening in this area of technology, and these devices would be better suited for wide-area collects, rather than small projects due to their cost projections. We hope to see better traction for these LIDAR’s in the future for geospatial users and communities.
A complete guide to What is LIDAR & also get to Know more about LIDAR, GIS, & Photogrammetry technologies Visit
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