ArcGIS REST Services Directory Login
JSON | SOAP

5_ft_Contors (MapServer)

View In:   ArcGIS JavaScript   ArcGIS Online Map Viewer   ArcGIS Earth   ArcGIS Pro

Service Description: The LiDAR survey occurred between July 31, 2015 and October 15, 1015 utilizing a Leica ALS80 mounted in a Cessna Grand Caravan. The systems were programmed to emit single pulses at around 369 kHz and flown at 1,500 m AGL, capturing a scan angle of 15 degrees from nadir. These settings were developed to yield points with an average native density of greater than eight pulses per square meter over terrestrial surfaces. To solve for laser point position, an accurate description of aircraft position and attitude is vital. Aircraft position is described as x, y, and z and was measured twice per second (two hertz) by an onboard differential GPS unit. Aircraft attitude is described as pitch, roll, and yaw (heading) and was measured 200 times per second (200 hertz) from an onboard inertial measurement unit (IMU). The LiDAR sensor operators constantly monitored the data collection settings during acquisition of the data, including pulse rate, power setting, scan rate, gain, field of view, and pulse mode. For each flight, the crew performed airborne calibration maneuvers designed to improve the calibration results during the data processing stage. They were also in constant communication with the ground crew to ensure proper ground GPS coverage for data quality. The LiDAR coverage was completed with no data gaps or voids, barring non-reflective surfaces (e.g., open water, wet asphalt). All necessary measures were taken to acquire data under good conditions (e.g., minimum cloud decks) and in a manner (e.g., adherence to flight plans) that prevented the possibility of data gaps. All QSI LiDAR systems are calibrated per the manufacturer and our own specifications, and tested by QSI for internal consistency for every mission using proprietary methods. OLC Chelan Project Overview Map OLC Chelan FEMA Data LiDAR Acquisition Dates 7/31/2015 - 10/15/2015 Area of Interest 201,078 acres Date Extent 215,029 acres Projection Universal Transverse Mercator (UTM) 10 North Horizontal Datum Vertical Datum NAD83 (2011), Epoch 2010.00 NAVD88 (Geoid 12A) Aerial Acquisition Vertical Accuracy Vertical Accuracy Results Hard Surface Sample Size (n) n = 123 GSPs FVA (RMSE*1.96) 0.038 m (0.123 ft.) Root Mean Square Error 0.019 m (0.063 ft.) 1 Standard Deviation 0.015 m (0.049 ft.) 2 Standard Deviations 0.039 m (0.127 ft.) Average Deviation 0.014 m (0.044 ft.) Minimum Deviation -0.080 m (-0.262 ft.) Maximum Deviation 0.052 m (0.171 ft.) Vertical Accuracy reporting is designed to meet guidelines presented in the National Standard for Spatial Data Accuracy (NSSDA) (FGDC, 1998) and the ASPRS Guidelines for Vertical Accuracy Reporting for LiDAR Data V1.0 (ASPRS, 2004). The statistical model compares known ground survey points (GSPs) to the closest laser point. Vertical accuracy statistical analysis uses ground survey points in open areas where the LiDAR system has a “very high probability” that the sensor will measure the ground surface and reports the fundamental vertical accuracy value (FVA=1.96*RMSE). For the OLC Chelan FEMA study area, a total of 2,230 GSPs were collected. An additional 123 reserved ground survey points were collected for independent verification, resulting in a fundamental vertical accuracy (FVA) of 0.038

Map Name: 5 ft Contors

Legend

All Layers and Tables

Dynamic Legend

Dynamic All Layers

Layers: Description: The LiDAR survey occurred between July 31, 2015 and October 15, 1015 utilizing a Leica ALS80 mounted in a Cessna Grand Caravan. The systems were programmed to emit single pulses at around 369 kHz and flown at 1,500 m AGL, capturing a scan angle of 15 degrees from nadir. These settings were developed to yield points with an average native density of greater than eight pulses per square meter over terrestrial surfaces. To solve for laser point position, an accurate description of aircraft position and attitude is vital. Aircraft position is described as x, y, and z and was measured twice per second (two hertz) by an onboard differential GPS unit. Aircraft attitude is described as pitch, roll, and yaw (heading) and was measured 200 times per second (200 hertz) from an onboard inertial measurement unit (IMU). The LiDAR sensor operators constantly monitored the data collection settings during acquisition of the data, including pulse rate, power setting, scan rate, gain, field of view, and pulse mode. For each flight, the crew performed airborne calibration maneuvers designed to improve the calibration results during the data processing stage. They were also in constant communication with the ground crew to ensure proper ground GPS coverage for data quality. The LiDAR coverage was completed with no data gaps or voids, barring non-reflective surfaces (e.g., open water, wet asphalt). All necessary measures were taken to acquire data under good conditions (e.g., minimum cloud decks) and in a manner (e.g., adherence to flight plans) that prevented the possibility of data gaps. All QSI LiDAR systems are calibrated per the manufacturer and our own specifications, and tested by QSI for internal consistency for every mission using proprietary methods. OLC Chelan Project Overview Map OLC Chelan FEMA Data LiDAR Acquisition Dates 7/31/2015 - 10/15/2015 Area of Interest 201,078 acres Date Extent 215,029 acres Projection Universal Transverse Mercator (UTM) 10 North Horizontal Datum Vertical Datum NAD83 (2011), Epoch 2010.00 NAVD88 (Geoid 12A) Aerial Acquisition Vertical Accuracy Vertical Accuracy Results Hard Surface Sample Size (n) n = 123 GSPs FVA (RMSE*1.96) 0.038 m (0.123 ft.) Root Mean Square Error 0.019 m (0.063 ft.) 1 Standard Deviation 0.015 m (0.049 ft.) 2 Standard Deviations 0.039 m (0.127 ft.) Average Deviation 0.014 m (0.044 ft.) Minimum Deviation -0.080 m (-0.262 ft.) Maximum Deviation 0.052 m (0.171 ft.) Vertical Accuracy reporting is designed to meet guidelines presented in the National Standard for Spatial Data Accuracy (NSSDA) (FGDC, 1998) and the ASPRS Guidelines for Vertical Accuracy Reporting for LiDAR Data V1.0 (ASPRS, 2004). The statistical model compares known ground survey points (GSPs) to the closest laser point. Vertical accuracy statistical analysis uses ground survey points in open areas where the LiDAR system has a “very high probability” that the sensor will measure the ground surface and reports the fundamental vertical accuracy value (FVA=1.96*RMSE). For the OLC Chelan FEMA study area, a total of 2,230 GSPs were collected. An additional 123 reserved ground survey points were collected for independent verification, resulting in a fundamental vertical accuracy (FVA) of 0.038

Service Item Id: c5c8dd16fca545f09ef6673f06b25edc

Copyright Text: FEMA

Spatial Reference: 103180  (6597)


Single Fused Map Cache: false

Initial Extent: Full Extent: Units: esriFeet

Supported Image Format Types: PNG32,PNG24,PNG,JPG,DIB,TIFF,EMF,PS,PDF,GIF,SVG,SVGZ,BMP

Document Info: Supports Dynamic Layers: true

MaxRecordCount: 2000

MaxImageHeight: 4096

MaxImageWidth: 4096

Supported Query Formats: JSON, geoJSON, PBF

Supports Query Data Elements: true

Min Scale: 0

Max Scale: 0

Supports Datum Transformation: true



Child Resources:   Info   Dynamic Layer

Supported Operations:   Export Map   Identify   QueryLegends   QueryDomains   Find   Return Updates