1. Use of Mobile LiDAR in the Louisiana 2010 6 Inch Ortho Program Presented by Hugh Bender Sanborn Map Co. May 3 rd 2011

2. Mobile LiDAR Traditional Applications

3. GOHSEP 6 inch Imagery Project 2010 The project was awarded in late January 2010 with the contract award 2 nd week of February Negotiations expanded the project to include the entire state at 6 inch orthos. Time was not on our side! Over 90,000 exposures 52,000+ square miles Leaf Off conditions 1000 Control points

4. 4 4 Resources Digital DMC (4) – 12 or 8 bits per pixel radiometric resolution – RGB and CIR – 3cm/1.1" pixel resolution Digital Vexcel (2) – 16 or 8 bits per pixel radiometric resolution – RGB and CIR – 3cm/1.1" pixel resolution Imagery Collection Assets Digital orthophotography 0.125 ft sample

5. State of Louisiana 2010 Orthos Overview. Lessons Learned Such a project should take about 3 months to execute Remarkably we had a tremendous streak of good weather 4:5 days (4 days of collection out of 5) verses normal of 2:5/6 days Another assist – 2 late in the winter freezes Mobilized 12 planes in all including all Sanborn DMC and Vexcel Numerous other company planes contributed 6 planes Contracting Hint! Schedule your contract for signing in Dec. or early January at the latest. You can tell the contractor when to start You can’t turn the clock back!

6. 6 Optech Lynx Images Courtesy of Optech,WH Pacific, ADS Inc

7. What drove the Mobile LiDAR decision? Simple Logistics! Already in Louisiana USACE NO Mobile Survey Demo Used for a levy area. When assets are in the same area then it becomes affordable Plus – It had not been done!

8. The Process Traditional Process (Panels or Photo ID Points) A photogramatrist: sets up a network Through google earth or similar imagery programs he identifies specific areas for a surveyor to go out and capture a point. This alone takes weeks to accomplish, then the surveying firm(s) must cover the state. Problem areas must be reworked. Mobile Process Guidelines are created and the mobile crew has much more flexibility Limitation = Trees and other obstructions hindering the GPS 20-25 usable points per shot

9. Mobile LiDAR By the Facts How this was better No need to set up static station to survey discrete points. “Drive by” survey, collecting several photos ID locations within a collection swath. Planned and collected 1100 points & used 890. Obtained 10 cm vertical or 1/3 of the RMSE

10. Mobile LiDAR and GOHSEP 6 inch Imagery Project 2010 Preplanning Takes some experience! Not the same strategy as with static tripod surveys. Features Only road features typically captured which limits some options for photogrammetric control.

11. Mobile LiDAR Advantages Allowed us to pick numerous points that were visible for the orthos. Once we had a LiDAR swath, it allowed us to pick and chose the best point Real time savings. - better selection - multiple options - and pick the best one.

12. Mobile LiDAR Advantages Traditional costs are: $250*1000 points = $250,000 Cost advantages Can collect data at over 50 MPH, therefore saving time over longer traverse distances TIME ADVANTAGES Can begin processing data immediately after day’s collection

13. Mobile LiDAR Advantages Advantage: 1) Proved extremely useful in urban areas! 2) Faster collection and processing in especially in urban areas and some rural locations 3) Photogrammetrist always had several choices for ideal control location.

14. Mobile LiDAR Disadvantages Disadvantage: 1) Rural areas. To much driving and GPS limitation on remote points. 2) Trees interfere with collection. 3) Coastal Areas: 1) Limited experience with coastal photo identifiable point 2) Would consider mobile lidar on a boat. 4) Had to stop more than anticipated

15. No Good Deed Goes Unpunished! What we would not do. Quick orthos after the BP Oil Spill Response. That worked well for the 1 foot imagery. We could process those and deliver in weeks. Did not work for the 6 inch imagery 6 inch imagery is no longer considered a “Quick Ortho Product. The files are so large that it is similar to processing original ortho. 1 foot to 6 inch orthos are a 4x increase in photo size Had to drastically increase processing capacity for the original project, the quickorthos made the processing problem worse.

16. Summary Would we use it again? Absolutely. Wide area and statewide rural mapping. ----------Especially when both assets are in one geographic area. Urban areas are prime for this type of system. Fast – Points collected quickly and lots of choices Lots of points to chose from Overall less expensive Works the same way when you get down to it. A little a little more flexible because you can pick from numerous visible points.

17. Hugh’s Soapbox Mobile LiDAR is a great technology tool! But be careful! Sometimes you just have to try something to see if it works. Mobile LiDAR is a viable tool for ortho production in certain circumstances In general mobile LiDAR is not a replacement for everything! Ask questions – know what you are trying to accomplish Orthos and Planimetrics are still the most useful and cost effective tool in the remote sensing toolbox More accurate! Millimeter accuracy. Is it required?