Summary

Description

USGS Contract No. 07CRCN0002 USGS Task Order No. 07002C0021. This delivery contains point cloud data in LAS 1.1 format, classified in the following manner. Class 0: Never Classified, Class 1: Unclassified, Class 2: Ground, Class 7: Low/High Point (Noise), Class 10: First and Only Return (not classified as ground), Class 12: Overlap, Class 14: First of Many Returns , Class 15: Second of Many Returns, Class 16: Third of Many Returns, and Class 17: Last of Many Returns (not classified as ground). The following are the collection parameters and equipment used to create these data sets. Aircrafts: Cessna 320 (N3443Q) and Piper Navajo (N6GR) Lidar System: Optech ALTM Gemini (03SEN145) Approximate Collection Altitude (Above Mean Terrain): 1800 meters Ground Speed: 180 kts Pulse Rate Frequency: 70 kHz Mirror Scan Frequency: 40 Hz Scan Angle (+/-): 16 degrees Beam Divergence: Narrow (0.25 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. Be aware the the Western Kenai Lowlands and Eastern Kenai Watershed have different accuracies and point spacings. Read this metadata record throughly to determine what the accuracies and point spacing are for your area of interest.