F.A.Q.

What is LiDAR?

LiDAR stands for "Light Detection And Ranging".

Remote sensing technology that uses laser light to sense surface attributes.

A laser beam is used to scan the ground and returning reflections are recorded in the sensor. Data like intensity, distance, scan angle, echo and time stamp can be recorded and processed later.

Lasers used in LiDAR units are kept "eye-safe" which means that direct visual exposure will not harm the eye or skin.

How is the Data Collected?	back to TOP
This graphical illustration shows 2 airborne platforms: Plane and Helicopter. Sensors are mounted and calibrated in each case. Sensors record First, Second and Final returns of the beam. This is useful in classification of the data during the post post-production process. Image 2 shows the scanning pattern of the sensor.

How does the Scanner Work?

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ALTM 3100 100kHz System:

The LiDAR system emits an optical pulse which is reflected off an object on the ground. The pulse is returned to the system receiver and the time passed is measured by an high-speed counter. The time measurement is converted into distance and location using data from the counter, navigation GPS units, and IMU - Inertial Measurement Unit.

The ALTM 3100 is capable of emitting 4 pulses onto one location and there fore measuring more valuable data. This is very helpful with classification of collected data.

The evolution of airborne laser mapping continues; the ALTM 3100 offers area coverage rates as high as 100 kHz at 1,100 m altitude, producing elevation data of unparalleled density and unprecedented low cost per posting. Additionally, the system can fly as high as 3,500 m with coverage rates as high as 33 kHz

Airborne Imaging has acquired a 100 kHz Optech ALTM 3100 Airborne Laser Terrain Mapper with unparalleled capabilities.

Sample of an Aircraft Platform:	back to TOP
Here is a sample of LiDAR in action. The scanner is mounted in a plane. Plane is equipped with 2 GPS units and an IMU-Inertial measurement unit.