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measurements (returns) per pulse (first, second, third, and last). All overlapping flight lines will <br />be flown in opposing directions to maximize detection of swath -to -swath inconsistencies and <br />used to resolve system misalignments. Using a combination of automated and manual <br />techniques that are tailored to the particular land cover and terrain of the study area, Lidar <br />processing will include kinematic corrections, calculation of laser point position, relative <br />accuracy testing and calibrations, classification of ground and non -ground points, assessments of <br />statistical absolute accuracy, and creation of ground surface models. <br />Survey Control <br />NV5G, Inc. survey team will perform the ground survey work. Depending on acquisition <br />logistics (configuration of sites, access, schedule, and weather), the team will use one or more <br />appropriate methods to enable geo-spatial correction of aircraft positional coordinate data. These <br />include conventional base supported CBS') survey control, TerraPos® Precise Point Positioning <br />(`PPP'), or Trimble® CenterPointTM Post -Processed Real -Time Extended (`PP-RTX'). To verify <br />Lidar point calibration and enable accuracy assessment, NV5G, Inc's field crew will collect <br />ground check points (GCPs) using GPS-based real-time kinematic (RTK) survey techniques. For <br />an RTK survey, the ground crew uses a roving unit to receive radio -relayed corrected positional <br />coordinates for all ground points from a GPS base unit set up over a survey control monument. <br />The roving unit records precise location measurements with an error (a) of <3 cm relative to the <br />base control. NV5G, Inc's team will distribute a suitable number of hard, bare earth ground <br />check points (GCPs) on level slope throughout project areas, as feasible given road access and <br />GPS conditions. <br />NV5G, Inc. will collect checkpoints for the Non -vegetated Vertical Accuracy/Vegetated Vertical <br />Accuracy (NVA/VVA) calculations. Per the latest American Society of Photogrammetry and <br />Remote Sensing (ASPRS) recommendations, NV5G, Inc. will require additional NVA and VVA <br />points as shown in Table 1. All checkpoints for VVA will fall within the Digital Elevation <br />Model (DEM) footprint. All ground survey operations will be conducted under the supervision <br />of a Washington State professional licensed surveyor who will also certify the accuracy of <br />control monument locations. The techniques for establishing all ground check points will be <br />outlined in the Report of Survey, including the identity, locations, and position residuals of all <br />GCPs used to evaluate survey accuracy. <br />Area <br />NVA <br />Count <br />VVA <br />Count <br />Calibration <br />Points <br />WALiY2 6,830,080 acres (10,672 <br />square miles) <br />125 <br />35 <br />235 <br />Table 1. NVA/VVA Checkpoint and Calibration Point Count <br />The following vertical accuracies will be met or <br />exceeded: <br />o RMSEz < 10 cm (non -vegetated Swath, DEM) <br />o NVA < 19.6 cm 95% Confidence Level <br />(Swath, DEM) <br />Page 1 2 <br />