Comments for Jason Amadori.com

Comment on Mobile LiDAR to Support Roadway Resurfacing by Jason

Jason — Fri, 24 Feb 2012 14:59:23 +0000

I just sent you an example of a typical control layout that is the CalTrans MTLS standard that is being used for many of our mobile LiDAR projects. Just to clarify, the project we are discussing here only used the control to “validate” the absolute accuracy of the point cloud. The CalTrans method was used for another client interested in exploring another method of “transforming” the data to ground control – more of a surface fitting routine as opposed to letting the IMU carry you between GPS epochs. That being said, we aren’t using the VRS networks because our technique relies upon a static base station for the rover to post-process against using a very short baseline. The baselines for the VRS networks can be short or long, but this project was pretty small and we felt this technique could work best. Now, if you were collecting an entire County or State, VRS could be a much better solution – you just need to understand what errors you may be introducing into your error budget.

Ultimately, we try to think practically about the application of this technology. the CalTrans methodology provides a very high level of accuracy for small projects because of the heavy control that has to be set to Transform and Validate points. Base Stations work well when you can babysit the setup or put it in a secure area – you can set it up, collect and then break it down very efficiently. VRS is more cost-effective for much larger collection areas, so it is all about the application of the technology to fit the needs and budget of the project!

Comment on Mobile LiDAR to Support Roadway Resurfacing by Yosie3

Yosie3 — Fri, 24 Feb 2012 13:41:18 +0000

Jason: thanks for the detailed response. What would a typical spacing between control and how far apart would you need cross sectional data. Can survey control be eliminated with VRS, can mobile GPS at highway speed use VRS?
Your Blog is the best on the web for LiDAR, please keep blogging about your innovative techniques.

Comment on Mobile LiDAR to Support Roadway Resurfacing by Jason

Jason — Fri, 24 Feb 2012 13:20:39 +0000

We typically set survey control throughout the project on hard, flat surfaces that are easily identified in the LiDAR point cloud. Paint stripes and gores work best because their vicinity is pretty flat without many elevation changes in the area. This is important because we are mainly concerned with the Z elevations across the project to make sure that the overall surface met the project accuracy of 0.1 foot based on the control. Also, we had an independent surveyor run some cross-sections throughout the project to make sure the surface was within accuracy tolerances as well. We combined all of these “checks” into the final accuracy assessment report for the project and provided those results to the client.

Our survey control was set using Fast Static Setups (Trimble R8) and post-processed using the dual base stations set in the field. I also don’t think it is possible to eliminate survey control because we always need a way to “prove” to the client that we achieved a specific absolute accuracy across the project.

Thanks for the questions! Jason

Comment on Mobile LiDAR to Support Roadway Resurfacing by yodie3

yodie3 — Thu, 23 Feb 2012 18:10:13 +0000

Jason: This is a great article. Can you say what the survey control was set at. Is there a specific density or spacing that is suggested over flat terrain for producing Survey grade LiDAR. What was the survey control, RTK plus vertical leveling, using a base station?

Also if you had a VRS (Virtual Reference Station) to tie to the GPS to via cellular connection, would you be able to elliminate the need for survey Control?

Comment on My Background by Jason

Jason — Mon, 05 Dec 2011 12:41:11 +0000

Yusuf,

We use a program called “Crack Scope” that is commercially available here in the US.

http://www.utexas.edu/research/ctr/pdf_reports/0_5708_P4.pdf

It works well for many roads here in the US, but does not catch all cracking along the road.

Good luck! Jason

Comment on What are you going to do with your NERC data? by Martin Flood

Martin Flood — Fri, 13 May 2011 21:07:15 +0000

Nice write-up Jason. I realize PLS-CADD is the 800-lb gorilla in the room on the line engineering side, but are you aware of any competing products in this space? I’ve been talking with lots of PLS-CADD users, but I’d like to get an alternative perspective (if there is one) on how other CAD packages support lidar data for thihs application.

Comment on Mobile LiDAR to Support Positive Train Control by Jason

Jason — Mon, 02 May 2011 17:18:29 +0000

This data was collected from a Helicopter platform. Jason

Comment on Mobile LiDAR to Support Positive Train Control by Fred

Fred — Mon, 02 May 2011 17:16:55 +0000

Was the aerial data acquired via fixed wing or helicopter?

Comment on Mobile LiDAR to Support Positive Train Control by 3D-mobiiliskannaus Ruotsissa | nordicgeocenter

3D-mobiiliskannaus Ruotsissa | nordicgeocenter — Thu, 28 Apr 2011 16:58:55 +0000

[...] PS Heti perään huomasin Jason Amadorin esittelevän Rieglin VMX-250 mobiiliskannerilla skannattua rautatietä. [...]

Comment on Mobile LiDAR and Cross-Slope Analysis by Mobile LiDAR and Pavement Resurfacing - LiDAR News

Mobile LiDAR and Pavement Resurfacing - LiDAR News — Wed, 27 Apr 2011 22:00:48 +0000

[...] out Jason Amadori’s blog post on the use of Mobile LiDAR to measure pavement cross slope. His company DTS/EarthEye teamed with [...]