{"id":6311,"date":"2015-08-23T18:23:51","date_gmt":"2015-08-23T23:23:51","guid":{"rendered":"http:\/\/gisgeography.com\/?p=6311"},"modified":"2025-03-29T12:35:37","modified_gmt":"2025-03-29T17:35:37","slug":"lidar-light-detection-and-ranging","status":"publish","type":"post","link":"https:\/\/gisgeography.com\/lidar-light-detection-and-ranging\/","title":{"rendered":"A Complete Guide to LiDAR: Light Detection and Ranging"},"content":{"rendered":"\n
\"Capitol<\/figure>\n\n\n\n
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LiDAR 101<\/h2>\n\n\n\n

LiDAR is fundamentally a distance technology<\/strong>. From an airplane or helicopter, LiDAR systems send light to the ground.<\/p>\n\n\n\n

This pulse hits the ground and returns to the sensor. Then, it measures how long it takes for the light to return to the sensor.<\/p>\n\n\n\n

Recording the return time<\/strong> is how LiDAR measures distance. In fact, this is also how LiDAR got its name \u2013 Light Detection and Ranging.<\/p>\n\n\n\n

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LiDAR (Light Detection and Ranging) works by emitting laser pulses and measuring the time it takes for the reflected light to return.<\/p>\n<\/blockquote>\n\n\n\n

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How LiDAR Works<\/h2>\n\n\n\n

LiDAR is a sampling tool. What I mean by that is that it sends over 160,000 pulses<\/strong> per second. For every second, each 1-meter pixel gets about 15 pulses. This is why LiDAR point clouds create millions of points.<\/p>\n\n\n

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\"Airborne<\/figure>\n<\/div>\n\n\n

LiDAR systems are very accurate because it\u2019s being controlled in a platform. For example, accuracy is only about 15 cm vertically and 40 cm horizontally.<\/p>\n\n\n\n

As a plane travels in the air, LiDAR units scan the ground from side to side. While some pulses will be directly below at nadir, most pulses travel at an angle (off-nadir). So when a LiDAR system calculates elevation, it also accounts for the angle<\/strong>.<\/p>\n\n\n\n

Typically, linear LiDAR has a swath width of 3,300 ft. But new technologies like Geiger LiDAR can scan widths of 16,000 ft. This type of LiDAR can cover much wider footprints compared to traditional LiDAR.<\/p>\n\n\n