Summary

Description

The Matanuska Susitna Borough LiDAR/Imagery Project covers 3680 sq/mi of the Matanuska-Susitna Borough in Alaska. Project parnters and funding sources include: Coastal Impact Assistance Program, Alaska Industrial Development and Export Authority, Alaska Energy Authority, United States Geological Survey, Matanuska Susitna Borough, United States Army Corps of Engineers, United States Fish and Wildlife Service, The Nature Conservancy, National Oceanic and Atmospheric Administration, Mat-Su Salmon Partnership, and Alaska Pacific University. This dataset contains lidar point clouds in LAS 1.2 format, originally classified in the following manner. Class 1: Unclassified Class 2: Ground, Class 3: Low Vegetation (less than 6 feet above ground surface), Class 4: Medium Vegetation (between 6 and 15 feet above ground surface), Class 5: High Vegetation (greater than 15 feet above ground surface), Class 6: Buildings, Class 7: Error Points, Class 8: Contour Keypoints, Class 9: Water, Class 10: Breakline proximity ground points, Class 11: Powerlines, Class 13: Noise (unclassifed data 1 foot or less above ground), Class 14: Bridge Deck. Classifications were modified slightly by changing class 10 to class 2 with user bytes set to 2, changing class 11 to 16, and changing class 13 to 15. The following are the collection parameters and equipment used to create these data sets. The Leica sensor was used for flights in the northern half of the Core Area. All other flights were flown with Optech sensors. Aircraft: Cessna 310(N7516Q), Piper Navajos (N6GR,T73TM and 812TB), Beechcraft KingAir (N898WW) Lidar Systems: Optech ALTM Gemini (03SEN145 and 07SEN201) and Leica ALS 70 Approximate Collection Altitude (Above Mean Terrain): Optech--1400 meters, Leica--2200 meters Ground Speed: Optech--150 kts, Leica--160 kts Pulse Rate Frequency: Optech--70 kHz, Leica--163.6 kHz Mirror Scan Frequency: Optech--40 Hz, Leica--41 Hz Scan Angle (+/-): Optech--17 degrees, Leica--16 Degrees Beam Divergence: Narrow (0.3 mrad) Accuracy statements are based on areas of moderate terrain, with points classified as ground. Diminished accuracies are to be expected in areas of extreme terrain and dense vegetation. The accuracy of each point is expected to meet the vertical accuracy standard, derived products may be less accurate in areas of extreme terrain and dense vegetation due to a lesser number of points defining the ground in these areas. Classified data sets such as this one may have varying posting due to some pulses not reaching the ground.