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LiDAR scans are finding hidden Roman roads and cutting crime

wired.co.uk

41–50 of 79 posts

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#41
post #6

Has anyone seen any nice examples of work done with the open LiDAR data?

I downloaded all the 1m dsm composite data from the Environment Agency and Natural Resources Wales and used C#, System.Drawing.Graphics and hefty server from AWS EC2 to render 2 million png files, which I then moved onto a Scaleway C1 bare-metal ARM server, to produce this slippy lidar map of England and Wales: https://houseprices.io/lab/lidar/map

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#42
post #6

Has anyone seen any nice examples of work done with the open LiDAR data?

If you're looking for just general examples and inspiration for things that can be done with LIDAR data, the LAStools blog [1] has a lot of em. Their mailing list is interesting as well.

I've been using LIDAR data for doing canopy height modeling, and screening remote areas for possible exceptional/champion trees prior to checking it out in person.

Haven't put anything online yet because I'm very new to GIS and this sort of thing, and am still getting over the horror of what it takes to build a functioning workspace and data pipeline.

("Just take this TIFF and convert it to a CSV" is a phrase I never thought would make sense, but here it does.)

[1] https://rapidlasso.com/blog/

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#43

Self driving cars have lowered some LIDAR costs a factor of 20, with a promise of far more. I wonder if this can translate over into archeology and geology. Imsaw one project at SIGGRAPH using a cheap LIDAR.

If you're surveying on a national scale, then the costs of chartering flights (or driving around with drones) is going to keep costs high in the near future even if the surveying equipment itself plummets in cost

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#44

"the power to deploy these technologies at scale will only be deployed to fight serious crime" [proceeds to use dragnet to crack down on people dumping stuff in the woods]

This tech isn't going to be able to catch people dumping stuff in the woods unless they're doing it on an industrial scale in their own woods to avoid a few million quid in landfill tax.

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#45

"the power to deploy these technologies at scale will only be deployed to fight serious crime" [proceeds to use dragnet to crack down on people dumping stuff in the woods]

There is no surveillance of actual people, the government just found a cheap way to find out that their own land had an unexpected change. Finding suspects seems to be old fashioned police work. I find it very hard to find any arguments against this use of the data

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#47
post #13

Anyone know where I could license/purchase hi-res LIDAR scans for use in game development?

The data from the Puget Sound LIDAR Consortium [1] is freely available, you just need to ask for an account. (Not 100% sure on licensing terms, though.) Seattle / King County just finished a rescan in 2016/2017 and the data is stunningly good. [2] Really good consistency and density. The DLM/classification/cleanup seems excellent. [1] http://pugetsoundlidar.ess.washington.edu/ [2] (private, need an account) http://pu…

Heh. Good to see people like the products.

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#48

Self driving cars have lowered some LIDAR costs a factor of 20, with a promise of far more. I wonder if this can translate over into archeology and geology. Imsaw one project at SIGGRAPH using a cheap LIDAR.

A lot of the cost of doing LIDAR surveys isn't just the LIDAR sensor itself.

eg, a typical high-quality survey will involve:

- Something like a Leica ALS80 [1]

- A Cessna + good Pilot, the plane needs to be really well instrumented.

- A team of surveyors on the ground to establish ground controls, and occupy points for GPS RTK calculations

- A bunch of post-processing to normalize the data, remove birdies and pits, do ground classifications, etc. (The raw data from the sensor before the processed point cloud is built is really really raw.)

A much cheaper approach which seems to be catching on is UAV photogrammetry. It's processing intensive, but no special sensors are required, and in the end you still get a pointcloud. Sensefly is a company that makes these types of UAVs.

[1] https://leica-geosystems.com/en-us/products/airborne-systems...

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#49
post #4
post #3

I have a question about self-driving cars (SDCs). Some time ago it was mentioned that SDCs can't use deep-learning because it is not sufficiently reliable, and that instead techniques like LiDAR should be used to recognize objects. However, this made me wonder: how does the car recognize road-signs and traffic lights?

I think you're confusing things. Deep Learning is a method of machine learning. LiDAR is a tool that collects depth data. Using Deep Learning on flat image data to try and detect depth is unreliable, hence SDCs use LiDAR to detect depth. They also use image data from the visible spectrum and beyond to read road signs. etc.

Ok, but what if the deep learning software of the SDC confuses a "no entry" sign with a 100mph sign?

Or is DL classification at 100% accuracy?

Re: LiDAR scans are finding hidden Roman roads and cutting crime

#50
post #2

For those unaware, all scientific press releases in the UK must express areas in football pitches, and volumes in double-decker buses.

It is unhelpful when it’s 32 million of them, and especially so when the size of a football field is variable.

> the size of a football field is variable

Sure, maybe the local, community field you and me play on, but not the ones where "real" matches are played. They have a standard size.

FIFA for example have the dimensions in their first law: http://www.fifa.com/mm/Document/FootballDevelopment/Refereei...

Probably they mean a standard football field.

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