National High Speed Rail Corporation Limited will be adopting Light Detection and Ranging Survey (LiDAR) technique using Laser enabled equipment mounted on a Helicopter for conducting ground survey for the preparation of Detailed Project Report for the proposed DelhiVaranasi HSR corridor.
- The proposed Delhi-Varanasi HSR alignment covers mixed terrains including densely populated urban and rural areas, Highways, Roads, Ghats, Rivers, Green fields etc, which makes this activity more challenging.
- National High Speed Rail Corporation Limited (NHSRCL) has been entrusted with the work for preparing Detailed Project Report for the Delhi-Varanasi HSR Corridor by the Ministry of Railways.
- The tentative length of the corridor is about 800 km, the alignment and stations will be decided in consultation with the government.
- It is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth.
- These light pulses—combined with other data recorded by the airborne system— generate precise, three-dimensional information about the shape of the Earth and its surface characteristics.
WORKING OF LiDAR:
- LiDAR follows a simple principle — throw laser light at an object on the earth surface and calculate the time it takes to return to the LiDAR source. Given the speed at which the light travels (approximately 186,000 miles per second), the process of measuring the exact distance through LiDAR appears to be incredibly fast.
- A lidar instrument principally consists of a laser, a scanner, and a specialized GPS receiver.
- Airplanes and helicopters are the most commonly used platforms for acquiring lidar data over broad areas.
SOURCE: ECONOMIC TIMES