Friday, July 22, 2011

Mobile LiDAR: Positioning Systems

In my most recent article for LiDAR News, I provide an overview of Positioning Systems for Mobile LiDAR.  It is a little more in depth than a blog posting I prepared back in 2009 titled Measuring Systems Part 1 - Positioning.

Mobile LiDAR is a system comprised of various components that are connected to provide a solution.

My belief is that the Position and Orientation System (POS) used to develop the Smoothed Best Estimate of Trajectory (SBET) is the distinguishing factor between available Mobile LiDAR systems. The ability to accurately position the vehicle has downstream advantages for the initial LiDAR processing and subsequent control adjustment.

Cheers!
Stephen

Saturday, July 16, 2011

Mobile LiDAR Blog goes Mobile

Following up on the recent redesign to the blog, I  applied a mobile template so it can easily be viewed on your smart phone or other mobile device.  Since it seems we're all on the go these days, it will be easier to check in to see the latest postings.

Sample of the Mobile Template

In addition, I've included the QR code that will take you directly to the site.  After having a Blackberry for nearly a decade, I'm still getting used to my iPhone keyboard and the code comes in handy.
Let me know what you think of the recent changes.

Cheers!
Stephen

Thursday, June 30, 2011

Baker's Dozen: 13 Laws of Mobile LiDAR

A little over a month ago, our Ridgeland office hosted a visit by Baker's CEO, Brad Mallory.  During a presentation of projects our Transportation group was working on throughout Mississippi, it was quickly observed that several of the slides had 13 projects listed - a Baker's dozen.

From that meeting, an idea was born to develop "Baker's Dozen: 13 Laws of Mobile LiDAR."  These Laws were developed after much thought and consideration.  In coming posts, I will explain each of the Laws in detail providing further explanation.  

Without further ado, I unveil the Baker's Dozen: 13 Laws of Mobile LiDAR (also currently being chiseled on a slab of granite):
  1. Too much is better than not enough.
  2. Sometimes more is just more, not better.
  3. Hard drives are cheap, time isn’t.
  4. Consistency counts; stop guessing.
  5. When someone wants “full planimetrics,” they really don’t.
  6. The stated laser range is X’, but the lasers are only capturing data to Y’; and Y is definitely less than X, yet nobody can tell you what Y is…
  7. The data you capture is only as good as the applied control.
  8. Today’s best practices will be tomorrow’s old habits.
  9. Field vs. office time ratios are pipe dreams.
  10. Mobile LiDAR systems are not created equal, and neither are the operations behind them.
  11. Off-the-shelf processing software will only do 50% of what you need it to do.
  12. When the system encounters issues, take a breath and reboot.
  13. Mobile LiDAR is not all fun and games, but it does feel like it some days.  

Feel free to let me know what you think.  Perhaps we can have a committee gathered to debate them or formalize some agreement.

Cheers!
Stephen

Monday, June 27, 2011

Riding the Rails

Back in March, Baker performed a Mobile LiDAR collection of a high speed rail corridor encompassing approximately 240 miles (opposing tracks along the same corridor).  Now that the primary products have been delivered, I took an opportunity to create several screen captures of the collection.  The two images below present different views of the same section of track.

Facing northwesterly, the screen capture clearly depicts the ability to capture a number of elements beyond the rail features.  The handiwork of local "artists" is evident thanks to the intensity returns from the system.

An opposite view from the image above shows the extent of overhead electric distribution, communication and fiber optic  utilities.  Also present are supporting guy anchors, a single mile post and other features necessary to develop engineering design drawings.
The detail of information captured in a single collection is quite impressive.  In addition to the planimetric feature extractions and track geometries, Baker developed a digital elevation model following constraint of the Mobile LiDAR collection.

Let me know what you think.
Stephen

Wednesday, June 15, 2011

Complexities of a Mobile LiDAR Survey

A few weeks ago, my fifth article for LiDAR News was published.  The article, titled "Complexities of an Urban Survey," discussed our recent collection of Charleston, WV.  The collection encompassed an incredibly varied urban and rural environment along 350 miles of public rights of way (collected in opposing directions).  Through project planning, we attempted to mitigate or minimize the known challenges we were going to face.  

The images presented in the article are shown below:

As the article states, we established control target layout for a local survey firm.  Above is a representation of a Google Earth KMZ depicting the control point layout.

Each SBET (sometimes a few a day due to weather) were exported to a Google Earth KMZ to perform cursory review of status.

Our Mobile LiDAR crew and Program Manager, Aaron Morris, provided an "Open House" to city staff and the media.
My next article for LiDAR News will be on the Position and Orientation System.  Should you have a topic to consider, leave me a comment.

Cheers!

Stephen