Last updated on July 20th, 2023 at 11:02 am
Since the scientific revolution, there has been tremendous progress in the field of surveying. Systems such as Lidar and remote sensing, which have lasers, scanners, and specialized GPS, are commonly used by scientists to examine the earth’s surface. Besides, mapping professionals use the techniques to inspect both humanmade and natural environments to generate precise, accurate, and flexible maps. This article provides a high-level overview of Lidar and remote sensing principles and their main applications.
By definition
Lidar
That is an active remote sensing system that uses light inform of a pulsed laser to measure vegetation height across a wide area. These light pulses merged with the airborne system’s data provide precise 3D information about the earth’s shape and its surface features. Furthermore, the Lidar instrument mainly consists of lasers and scanners and is commonly used in helicopters and airplane platforms to obtain data over broad areas.
Types of Lidar
- Topographic
This type of Lidar typically uses a near-infrared laser to map the land. Topographic maps define the shapes of the earth’s surface. This information serves many purposes, such as ensuring that geological and geophysical surveys are precise.
- Bathymetric
This survey measures the depth of a water body as well as mapping the underwater characteristics. Several methods can be used in survey techniques, for instance, multi-beam, single beam, sub-bottom profilers, and Ecomapper autonomous underwater vehicle. Additionally, this survey method is used in many different research types, such as water quality studies, leakage, scour, and dam removal.
- Range finders
Like the radar, it discharges a pulse of light and determines the time interval between when the pulse is released and when its reflection is detected. Also, it’s used to measure the distance of an object due to its shorter wavelength.
- Doppler Lidars
That uses a doppler shift and a small change in wavelength because of the surface’s motion to measure the target’s speed. Besides, it causes the swap in pitch as the train whistle or a car hoot as it approaches you, then it recedes from you.
Importance of Lidar data
- Improves the efficiency of geologic mapping, raises the number o unit that can be mapped and betters spatial precision of geologic maps.
- It backs up site-specific engineering studies by geotechnical firms.
- Help in mapping young deposits and landforms, which are the most vital for comprehending earth resources.
Remote sensing
That is a technique for observing, measuring, or monitoring a process or an object without necessarily touching the target under study. It includes optical and radio telescopes, cameras, and eyesight. Usually, the remote sensing instrumentation is not in contact with the object being observed, so; it allows the monitor to;
- Smooth local fluctuations by averaging over a large volume
- Examines large volumes economically and quickly.
- Measures processes without disturbance.
- It avoids difficult research areas.
Types of remote sensing
- Passive remote sensors
This type of sensor doesn’t involve energy sources on which the measurement is stationed. The eye and optical telescope are passive remote sensors, and they only rely on the external light source.
- Active remote sensor
It includes the use of energy sources on which the instrumentation is based. Besides, radar is commonly known for remote sensing.
My final thought
Lidar and remote sensing are two techniques used in the survey. The term lidar is a fusion of radar and light fusion, which are active remote sensing technologies that use light instead of radio or microwaves. Since Lidar generates its energy, unlike remote sensing, they are used during the day or night. The two systems are used in various companies, such as geology, mapping, and oceanography.
