I'm Cory Kell with Phoenix liar systems and in this video we will help you to understand the fundamentals of liar so stay tuned if you're new to ldar you've come to the right place this video will introduce you to the fundamentals of lar Concepts including what is the purpose of lar how is lar used how does lar work and what does this technology do let's begin with the purpose of lar lar or light detection ranging is a tool used to quickly accurately and densely measure 3D features from the world around us lar is a form of remote sensing meaning we aren't physically measuring things with our hands but rather using sensors to measure topography vegetation or other data across large areas we need remote sensing methods that can take many measurements quickly easily and accurately lar sensors can take hundreds of thousands of measurements each second and are represented in the form of a point Cloud the point cloud can be used in various analytical processes to take distance measurements compute volumes and model objects in three dimensions let's move on to talk about applications for this technology a lar system can be used for a variety of use cases lar can be used for vegetation structure mapping including vegetation height density and other characteristics across a region for analyzing vegetation over large areas surveyors use lar to rapidly map topography in vegetated areas significantly faster than conventional survey methods in a safe and and reliable manner lar is used in utility management to monitor vegetation encroachment on power lines and provide accurate change detection models for pipelines railroad tracks and waterways it is also utilized for roadway and Highway construction projects in the form of planning asilt mapping and for roadway maintenance assessments lar data provides accurate volume measurements at regular intervals for complex and intricate mining products some forms of ladar sensors can even penetrate water to map the submerged surface below this process is known as bimetric lar mapping in this way lar is used to monitor the shoreline of land waterer interface environments along rivers reservoirs oceans and more so how does lar work lar is an active remote sensing system meaning that the ladar system itself actively generates laser pulses used to take the measurements these laser pulses are pulses of light that travel from the sensor to the ground and reflect off of things like buildings and tree branches the reflected signal then returns to the lar sensor where is recorded and stored as a distance so how does lar measure distance in addition to emitting a laser pulse a lar system measures the time between when each pulse is sent from the system to the time it is reflected back to the sensor since the speed of light is known we can calculate distance using a simple mathematical formula distance equals speed time time with the help of positioning and orientation sensors within the ladder system distance is then represented as an elevation specifically a GPS or gnss identifies the X Y and Z location of the lar system and its position in the physical world and an inertial measurement unit or IMU provides the orientation or roll pitch and yaah of the lar system as it collects data position measurements are typically collected once every second orientation measurements are typically collected between 125 to 400 times per second these position orientation sensors are critical components and our in go for every aerial ladar system to precisely calculate where and when each point is collected in summary a ladar system is an active remote sensing system composed of components that emit the laser receive a return a signal and calculate the system's position and orientation to produce a geospatially accurate depiction of the world around us in the form of a 3D Point Cloud so how can light AR measure the ground through trees a laser pulse emits light energy as a bundle of photons as the photons move towards the ground they hit objects such as buildings trees and ground vegetation in the case of trees and vegetation some of the photons reflect off the branch and return immediately to the sensor however some of the photons actually pass through the gaps in the tree striking other features like lower branches or even the ground before returning to the lar sensor in this way multiple Reflections may be recorded from one pulse of light in the lar industry this is known as multiple returns some liar systems return two returns some three some four and some even return up to 15 returns to the sensor this depends on the power of the laser used in the system and a few other factors the result is a point cloud with true 3D representation of both the vegetation and ground data so to recap lar or light detection ranging is a tool used to quickly accurately and densely measure 3D features from the world around us millions of lar returns or measurements containing x y and z values are compiled and stored as a point Cloud which can be used in various analytical processes to take measurements compute volumes and more lar data can be used to estimate tree height measure power line sag detect changes in topography from one date to another and numerous other applications in the next few weeks we will release a follow-up video explaining lar system technology in more detail how to produce high accuracy drone-based lar data and what's needed for optimization [Music] we hope you enjoyed this video Phoenix lar systems is dedicated to making and sharing high quality content on this channel so if you learn something please subscribe and hit the like button and if you have any questions for us be sure to leave them in the comment section below thanks for watching we will see you next time hey [Music]