Wednesday, October 28, 2009

To Debunk or Not To Debunk - That is the Question

I sit here writing this blog today facing a difficult decision to make.  It's not a decision that I take lightly and one that I would gladly take advice on from you.

Shortly after installation of our system,  we captured an area in Bedford County, Pennsylvania little known to the outside world - especially to those who no longer take the time to get off the interstate and enjoy such roadside attractions as the Corn Palace, Wall Drug Store or Weeki Wachee Springs.  I am referring to Gravity Hill - a place described as:
"Cars roll uphill and water flows the wrong way. It's a place where gravity has gone haywire."
Since that day, I have avoided processing the collected data to keep from being the one to perhaps disprove what many have become to understand as a natural phenomena which occurs in an obscure, but beautiful, part of the Pennsylvania hills.  Having grown up in Florida and traveled the state quite extensively, I am all too familiar with Spook Hill.  I can vaguely remember sitting in the back of my grandparent's Cadillac when my grandfather put the car in neutral at the base of the hill and we proceed to roll backwards up the incline.  To say that I was a little spooked was an understatement.

As a father, I look forward to these "less exciting" experiences and may allow the data to go unprocessed.  Still, there is a part of me that wants to develop a bare-earth model and see that water really does flow up hill.  I leave it to you, the readers, should this data be processed?

To find a "Gravity Hill" in your area, check out this list.  Enjoy!

Friday, October 9, 2009

Baton Rouge - No Rest for the Crew

Huey P. Long Bridge
Following our East Coast Road Show, the Mobile LiDAR vehicle arrived "home" to Baton Rouge.  Although we managed to put over 3,000 miles on the vehicle in 3 weeks, our crew made their way back out into the field for collection of the Huey P. Long Bridge over the Mississippi River.
The bridge carries 4 lanes of US 190 (Airline Highway) and 1 line of the Kansas City Southern rail.  Our Mobile LiDAR crew made two passes in each direction and various approaches to capture the underlying support structures, levee, railway and roadways.
LA DOTD Offices and I-110
After the collection of Huey P. Long Bridge, our crew collected the Louisiana Department of Transportation and Development office along I-110.  They made several passes of the office building and surrounding approaches to generate dense coverage.  After processing the trajectory, I created a Google Map of the drive.  If you click on the location point, you can watch a YouTube video of the collection.

Monday, October 5, 2009

Atlanta - Spaghetti Interchange

In order to minimize traffic in the collection, our crew worked through the early morning hours to capture almost 20 different approaches to the I85 - I285 interchange in Northeast Atlanta.  Called the "Spaghetti Interchange" by locals, the data capture for the trajectory shown to the right took approximately 2.5 hours.  The Smoothed Best Estimate of Trajectory (SBET) provides a constant position and orientation of the vehicle to process with the laser range data to calculate X, Y and Z coordinates of all measured points (point cloud) - the minimum type of processing performed.

The image above shows intensity merged with colorization by height (blues are lower than reds).  The support structures, decking, retaining walls, barrier walls, and other roadway features were accurately captured with our vehicle traveling at 50 - 60 mph.