The world changed in the past 60 years. Many improvements in technology have shown how amazing our minds are. We have found different ways to create solutions to our world, making it easier and more efficient. One of the most useful improvements in technology trending right now, is the "LIDAR" Light Detection and Ranging . Lidar originated in the 1960s, shortly after the invention of the laser, but it was not until after 1971, during the Apollo 15 mission, that we realized how accurate and useful Lidar systems are. Astronauts used this laser altimeter to map the surface of the moon.
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Rotating LIDAR sensor |
What is Lidar? It is a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light. The acronym Lidar comes from
Light
Detection
and
Ranging, so it can be written as LiDAR, but it is acceptable to use Lidar, LIDAR, or LIDaR.
LiDAR uses the laser to illuminate a target and then analyze the reflection, the narrow laser makes possible to map objects with a high degree of resolution. But why if LiDAR has been around since the 70s, was it not used during the past years. The answer is it was not easy to construct in small sizes, the cost was really high and the complexity of the technology limited the applications (mostly government). However, due to the big advances in laser detection, computational speed, and memory storage, we now can use this technology for commercial applications.
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LIDAR Data |
Smaller, faster, smarter LiDAR makes possible direct measurements of complex and hard structures. LiDAR can be so accurate that it can develop 3D point clouds of a wide range of objects, such as - rocks, non-metallic objects, rain, chemical compounds, aerosols, clouds, and even single molecules. This means that this technology can detect almost any single and small point which is awesome if you think about the possible uses of it.
So where can we apply this technology? The answer is broad. Applications include:
- Agriculture, Archaeology,
- Autonomous vehicles, Biology and conservation,
- Geology and soil science
- Atmospheric remote sensing and meteorology
- Law enforcement, Military
- Mining
- Physics and Astronomy
- Robotics
- Spaceflight
- Surveying
- Transport
- Wind farm optimization
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LIDAR terrestrial |
Some of the most useful applications are Terrestrial scanning and Aerial scanning. Terrestrial scanning creates 3D models of complex objects like piping networks, roadways, archaeological sites, buildings, bridges, etc. One of the advantages of Terrestrial LiDAR is that objects can be measured remotely making operations such as measuring roadways under traffic
much safer.
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LIDAR Aerial |
If we take LiDAR to a larger level we have "Aerial scanning" which has many uses like measuring agricultural productivity, distinguishing archaeological remains, measuring tree canopy heights, determining forest biomass values, advancing the science of geomorphology, measuring volcano uplift and glacier decline, measuring snow pack, and the most important to surveyors and civil engineers, providing data for
topographic maps.
Topographic maps were usually created by Photogrammetry, the science of making measurements from photographs. The output is typically a map, drawing, measurement, or a 3D model of some real-word objects or scene. Many of the maps we use today are created with photogrammetry and photographs taken from aircraft. So why choose LiDAR to create topographic maps instead of Photogrammetry?
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Mobile LiDAR survey |
LiDAR sensors can be operated in any weather (Photogrammetry uses cameras which cannot be used all the time like when it's cloudy). The sensors are not affected by low sun angles which prevents useful photos. Furthermore, LiDAR can actually operate at night-more hours of useful flying per day means greater efficiency faster results, and more ground covered than photogrammetry. Rural and remote areas are easier and quicker to survey with LiDAR because each point has geo-reference location and elevation directly from the results. In other words, we do not need to do more processes to have accurate information. In addition, LiDAR creates 3D model directly from the returns, Photogrammetry instead requires the incremental comparison of a pair of stereoscopic photographs which is is indirectly and much more labor intensive. Photogrammetry requires contrast to see ground surfaces, and LiDAR results come directly from the returned signal.
LiDAR is a perfect tool for any Engineer. It can be used to have a 3D model for objects, areas, or any structure. The models can be uploaded to different computer software and used to create and develop new designs. Engineers can work in a specific area of construction and create designs quicker and smarter.
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LiDAR in Machine |
What is even amazing with this technology is that now days LiDAR can be used for Autonomous vehicle. After the engineer has finished his work and has all the geographic information loaded in his computer, he can use this information and upload it to a machine so it can work by itself. LiDAR is used to help the machine to detect obstacles and navigate safety through the environment. Using Global Position System (GPS) and the design information from LiDAR, the machine can move around the construction, excavating, hauling and moving material to the specifications given by the computer. It is a great advantage, it will help to construct more precisely and faster, if we finish the jobs faster, we will reduce the cost and increase production overall.
LiDAR uses a lot of memory data information, and that is one of the reasons many users of LiDAR have to use Terabytes (TB) = 1000 Gigabytes (GB), finding ways to create more memory for computers will help us to create more applications for this technology. LiDAR will become more and more popular in the future, and I am sure we will find more applications of this technology in many other fields.
References:
- [Rotating LIDAR Sensor], retrieved on October 22th, 2015 from http://www.roprodesign.com/projects/mechanicalprojects/lidar/
- [LIDAR data], retrieved on October 22th, 2015 from https://www.leidos.com/sites/default/files/imported/geospatial/images/lidar1.jpg
- [LIDAR terrestrial], retrieved on October 22th, 2015 from http://www.cartodata.com/technologies/lidarterrestre/
- [LIDAR aerial], retrieved on October 22th, 2015 from https://www.e-education.psu.edu/geog481/l1_p3.html
- [LIDAR aerial], retrieved on October 22th, 2015 from https://www.e-education.psu.edu/geog481/l1_p3.html
- [Mobile LiDAR survey], retrieved on October 22th, 2015 from http://www.mobilelidar.com/2013_09_01_archive.html
- [LIDAR in Machine], retrieved on October 22th, 2015 from http://www.equipmentworld.com/volvo-ce-unveils-siteaware-lidar-camera-combo-gives-equipment-operators-360-degree-vision-photos-video/