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Can anyone knowledgeable correct / confirm my understanding of why the Lidar technique works? The Lidar is able to penetrate (or just get in between) gaps in f
by supernova87a 4y ago
Can anyone knowledgeable correct / confirm my understanding of why the Lidar technique works?
The Lidar is able to penetrate (or just get in between) gaps in foliage which otherwise obscure or smooth out the features on the ground / dirt-level. So then by taking the lowest ground surface height reached in a certain patch of ground scanned (like sq. ft) you're able to "see" the actual ground?
If so, why didn't radar work previously? Too long wavelength?
Or that's like a continuous wave / average scan versus a point-by-point scan?
Thanks!
- czx4f4bd 4y agoGood question. > What makes lidar a better choice for many applications, including archaeology, is that the wavelength is about half a micron – tiny relative to radar wavelengths, which are measured in centimetres or decimetres. For details of a relatively small spot on the ground, lidar provides a precision that radar cannot match. Source: https://www.theguardian.com/science/2015/jun/20/lidar-radar-archaeology-central-america https://www.theguardian.com/science/2015/jun/20/lidar-radar-...
- AlotOfReading 4y agoRadar does work, there's just a trade-off between frequency and resolution. LIDAR is way up in the near-optical regime, so it has very poor penetration but the resolution is so high that you can see the small gaps in the canopy. Importantly, you can also do fancy signal processing with the reflectance and multiband stuff to distinguish man-made objects from foilage. That's uncommon in the archaeology world (unless using data where that's already been done), but the military and commercial people take full advantage.