- Open Access
- Total Downloads : 0
- Authors : Juhi Kushwaha, Mr. Naveen Dadhich
- Paper ID : IJERTCONV6IS17013
- Volume & Issue : V-Impact – 2018 (Volume 06 – Issue 17)
- Published (First Online): 05-01-2019
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License: This work is licensed under a Creative Commons Attribution 4.0 International License
B. Tech Scholar
Department of Electronics &Communication Vivekananda Institute of Technology
Jaipur, Rajasthan, India
Abstract:-Lidar stands for Light Detection and Ranging. Lidar refer remote sensing method that uses light in the form of a pulsed laser to measure distance to the earth. Lidar uses laser energy in radar fashion to observe meteorological backscattering as a function of range. Light detection and ranging represent a key method to investigate vertically resolved properties. It is consist the component that is laser, scanner and optics, photo detector and receiver electronics, position and navigation systems and sensor. The light detection and ranging has only two types that isAirborne LIDAR and Terrestrial LIDAR.
Keyword: Light detection and ranging (LIDAR).
Lidar refers to a distant sensing technology that emits sharp, focused beams of light and measures the time it takes for the reflection to be detected by sensor. And it is used to examine the surface of the earth. Lidar, which is popularly spelt Lidar and also known as LADAR or laser altimetry, is an acronym for light detection and ranging. Lidar beginning in the early 1960, shortly after in mintage of the laser and combined laser focused imaging with the time for a signal to return using propensity sensors and data acquisition electronics. Its first application came in meteorology, where the national center for meteoric research used it to measure legion. The normal public becomes aware of exactness and usefulness of Lidar system in 1971 during the Apollo 15 mission, when astronauts used a laser altimeter to map the region of the moon.
The two kinds of lidar detection that is coherent detection and incoherent detection or direct energy. Coherent detection is more sensitive than direct detection.Coherent systems generally use optical heterodyne detection. And the optical heterodyne detection is a method of extracting information encoded as modulation of the phase or frequency of electromagnetic radiation in the wavelength band of visible or infrared light. The light signal is compared with standard.
Mr. Naveen Dadhich
Department of Electronics & Communication Vivekananda Institute of Technology
Jaipur, Rajasthan, India
Figure: 1Lidar Technology
Figure: 2 Lidar Geometry Diagram
Lidar system consist of several major component that is
Photo detector and receiver electronics
Position and navigation systems
Solid state laser
It is the process of to emits the light for optical amplification founded on the stimulated emission of electromagnetic light. This is called laser device. The word laser emerged as a short word for light amplification by stimulating emissions of radiation.
Photo detector and receiver electronics:
In lidar two main technologies are used that is solid state photo detectors and photomultipliers.
Position and navigation systems:
Lidar sensors mounted on mobile platforms that are airplanes or satellites require equipment to determine the ultimate theory position and orientation of the sensor.
The lidar uses the active sensor which supplies its own light source.
Solid state laser:
By definition, there is no moving part in solid state electronics.
A phase array can highlight any direction using individual antenna microscopic array. Controlling the time (phase) of each antenna is a consolidated signal in a specific direction.
Flash uses a light source that publishes the viewing area in a pulse. Looking at the distance, a powerful explosion of light is required. Power is limited to those levels which do not harm human retina. Wavelength should not affect human eyes. However, low-cost silicon images do not read light in the safe spectrum of the eyes.
TYPES OF LIDAR:
There are two types of lidar that is
Airborne LIDAR: in airborne Lidar, the system is congealment in either a fixed-wing aircraft or helicopter. The infrared laser light is emitted toward the ground and recoil to the moving airborne Lidar sensor.
There are two types of airborne sensors that is.
Terrestrial LIDAR: Terrestrial LIDAR get- together very compact and highly simple points, which allowed special identification of object. These compact points clouds can be used to handling facilities, conduct highway and rail surveys, and even create 3D city model. There are two main types of terrestrial LIDAR that is.
There is a wide variety of application for lidar.
In Agriculture field
In Archeology field
In Autonomous vehicles field
In Geology and soil science
In Corona field
In Law enforcement field
In Defense field
In Digging field
In Physical science and astronomy
In Rock mechanics
In Spaceflight field
In Transport field
In Wind farm optimization
In Solar photovoltaic deployment optimization
In Video games
This technology has become an advanced technology which established method for collecting very dense & elevation data landscapes, LIDAR can assign high degree of accuracy & more detailed knowledge about the landscape than RADAR technologies so it is more applicable and efficient technology. It is used in world wide.
REFERENCES:. "LIDARLight Detection and Rangingis a remote sensing method used to examine the surface of the Earth". NOAA. Archived from the original on June 8, 2013. Retrieved June 4, 2016. . Oxford English Dictionary. 2015. p. Entry for "Lidar". . "Light Detection and Ranging". Ngs.noaa.gov. 2015-06-12.
Retrieved 2017-12-24.. Cracknel, Arthur P.; Hayes, Ladson (2008) . Introduction to Remote Sensing. London: Taylor and Francis. ISBN 978-0-8493- 9255-9. OCLC 70765252.