Thursday, September 29, 2016

As Seen on TV

The Mobile LiDAR team at Michael Baker International had the distinct pleasure of being showcased on the latest episode of Worldwide Business with kathy ireland®.  The segment, which aired on Sunday, September 25th on Fox Business Network, featured Peter Bonne, CEO of Orbit GT®.  As you’ve seen in previous posts (Picture of the Week and LiDAR Data & Orbit GT), Michael Baker utilizes Orbit’s Content Manager, Asset Inventory and Publisher software applications to exploit LiDAR and panoramic imagery through our own web-portal.

A look inside one of Michael Baker's Mobile LiDAR vehicles.
Michael Baker’s Mobile LiDAR equipment and personnel were represented throughout the broadcast, including interviews with Bob Hanson, Senior Vice President of Geospatial Information Technology and Scott Peterson, Systems Supervisor.  Each discussed the importance of Geospatial data in managing and maintaining our Nation’s infrastructure.

Michael Baker’s Bob Hanson discusses the role of Geospatial data in managing our Nation’s infrastructure.
Our LiDAR operations have employed Orbit GT’s software for the past year.  Publishing spherical imagery and LiDAR data has become a routine deliverable to our clients. By offering the data in an “easy to use” application our clients are empowered to make timely decisions without overwhelming them with “Big Data.” 

A view of the Orbit GT client application and published data as viewed through our web portal.

A low resolution video is provided:


To view this program in HD, go to:  https://vimeo.com/kathyireland/review/174216940/f19246eb7d

Cheers,
Stephen

Tuesday, September 20, 2016

By the Numbers: Positioning and Navigation


  • 4:  Number of individual positioning systems equipped on each of our 4 Mobile LiDAR systems: 1 dual antenna GPS/GNSS; 1 military-grade Inertial Measuring Unit (IMU); 1 Distance Measuring Instrument (DMI); and 1 GPS for vehicle navigation.
  • 200:  Frequency at which the vehicle’s position is updated every second (Hz).  The IMU fine-tunes initial positioning generated by the dual-antenna GPS/GNSS by combining readings attitude (pitch, yaw, roll) calculations with distance traveled (DMI) to produce an accurate position at 200 Hz.
  • 1:  Number of IMU’s onboard each Mobile LiDAR system.  One of our four IMU’s is also used by the U.S. Military as part of the guidance system of a Patriot Missile.  That system is regulated by the U.S. State Department through the International Traffic in Arms Regulations (ITAR) – needless to say, there’s a little bit of red tape to clear if we want to take that unit out of the country.
  • 12:  Number of miles of subterranean mine shafts surveyed during a previous project.  The combination of the IMU and DMI allow our systems to perform accurate collections during sustained GPS-outages using dead reckoning.  
  • 1,024:  Number of wheel rotation measurements performed every second.  Our DMIs are directly affixed to the vehicle’s wheel to ensure reliable readings. Due the inherent positional errors with GPS the DMI is not only used to indicate accurate distance traveled, but also to alert the system when the vehicle is stopped - called the "Zero Update".
  • 2:  The fluctuation in tire pressure (lbs.) which will result in inaccurate distance measurements.  During a collection, the DMI scale factor (a function of the tire's circumference) is constantly monitored and "calibrated" using other systems, including GPS.



Wednesday, September 7, 2016

Circling the answer through RANSAC

Here in Michael Baker's Mobile LiDAR Center of Excellence, we are routinely challenged with developing new ways to extract the most from our data. Our focus is to minimize the amount of human interaction required to extract a relevant piece of data from the voluminous point clouds we collect. Understanding our necessary and recurring requirements within automated processes is important to us for the types of products we deliver. Knowing requirements helps us to determine if we are in a “buy versus build” decision for a particular software automation task. Many software companies are developing robust commercial software tools for feature extraction from LiDAR point clouds. However, the rights to modify any commercially developed software and inherent intellectual property and licensing costs can make the “buy” decision onerous and costly for us.

Understanding the likely and underlying algorithms we’d choose to employ in any software we look to build, or buy and license is vital. As engineers, surveyors and subject matter experts with a deep awareness of LiDAR data and its processing we know what we want and need for automation. Knowledge and necessity are not mutually exclusive. They should optimally align to produce the best solutions. That Rolling Stones lyric comes to mind. Yet, we don’t agree with the song’s implied result when it comes to software: “You don’t always get what you want, but you get what you need.”

In the best case, we get what we want and also need as it comes to our requirements for LiDAR processing. Too many needs are fulfilled inefficiently with commercial software. We must avoid “kluge approaches” when fulfilling a specific software or task sequencing approach, so in house development allows us to fulfill these needs specifically and efficiently in our LiDAR processing.

As an example let’s examine how we might fulfill a very repetitive task while using a computer to find the precise center, radius and circumference of a circle within the chaos of thousands of LiDAR points in a point cloud through a combination of geometry and algorithm design.

RANSAC (Random Sample Consensus) is an iterative based outlier detection method. The basic principle of which has been evolved to work with geometric equations allowing the system to determine the best fit circle within the LiDAR point data as well as locating the center of the best fit circle. The system creates “slices” through the points at a specified thickness in the vertical plane then determines the best fit circle and center point for each slice. Once we determine the location of a phenomena that might represent a circular object, we can use an automation tool to facilitate automatic extraction.

The advantages of such a tool include:
  1. Ability to calculate the taper of any circular object ( columns, posts, poles, water tanks, etc.) and project the taper to a point that may be obscured by an object in the LiDAR data
  2. Determining if an object is leaning by analyzing the center points of all the slices along the height of the object
  3. Reducing the human error of manual attempts to extract the circle and center points.
We are continuously striving to expand our LiDAR data extraction capabilities at Michael Baker while appropriately making the correct buy or build choices with any software we utilize. When working with repetitive processes on tens of thousands of single functions of extractions per week, the simplest software process is better and more efficient for us. Geometric shapes are precise forms. They are mathematically consistent. Circles represent just one shape of the most basic and important forms of geometric objects. Squares, spirals, triangles are also basic forms. Extracting basic forms efficiently and cost effectively is very important to us.

We continually focus on getting everything right with one right extraction process at a time. This RANSAC system of processing is one of many developments that we will continue to exploit which sets us apart, ensuring Michael Baker International is the first name in LiDAR.

Regards,
Sandor

Sandor Laszlo, PE is a Software Engineering Supervisor with Michael Baker's Mobile LiDAR Center of Excellence.  Sandor's current focus is on the development of semi-automatous systems for extraction of features from LiDAR point cloud information. 

Monday, September 5, 2016

Happy Labor Day!

Today we celebrate the contributions of the American Worker to our country’s success.  All of our U.S. offices are closed this Labor Day in honor of those that have played a pivotal role in building our nation’s infrastructure. As we pack our whites and celebrate the unofficial end of summer, we’re also planning our continued deployment of innovative solutions to ensure “We Make a Difference”.

What is Mobile LiDAR?

Mobile LiDAR (Light Detection and Ranging) systems are comprised of vehicle-mounted lasers, cameras and GPS/INS navigation systems to capture highly-detailed and accurate three-dimensional (3D) topographic information for surveying and engineering applications. Michael Baker International became an early adopter of Mobile LiDAR technology by acquiring our first system in 2009, with further expansions in 2014 and 2015 that increased our fleet to four (4) Optech Lynx SG1 Mobile LiDAR systems. Over that period our systems have completed more than 300 projects throughout 29 different U.S. States (and multiple countries), and encompassing hundreds of thousands of miles. Our project portfolio includes applications in roadway design, 3D modeling, railroad corridors, signaled intersections, utility infrastructure, asset management, pavement condition assessment and airport infrastructure.