2017 OLC Topobathy Lidar: New River, OR

Quantum Spatial collected the New River, OR Topobathymetric LiDAR data for the Oregon LiDAR Consortium on 04/04/17.

Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base. Change to an orthometric vertical datum is one of the many options.

Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document. They will be in an orthometric datum.

The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer.

This graphic displays the footprint for this lidar data set.

Link to data set report.

Acquisition. Quantum Spatial collected the New River, OR Topobathymetric LiDAR data on 04/04/17. The survey used a Riegl VQ-880-G laser system mounted in a Cessna Caravan. Ground level GPS and aircraft IMU were collected during the flight.

Sensor: Riegl VQ-880-G

Maximum returns: Unlimited

Nominal pulse density: 6 pulses/m^2

Nominal pulse spacing: 0.408 m

AGL: 372 m

Speed: 110 knots

FOV: 40 degrees

Scan frequency: 50 hz

Pulse rate: 245 kHz

Pulse duration: 1.2 ns

Pulse width: 0.26 cm

Wavelength: 532 nm

Pulses in air mode: Multiple Pulses in Air

Beam divergence: 1 mrads

Swath width: 290 m

Overlap: 60%

Processing Steps (software used):

Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data. Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with sensor head position and attitude recorded throughout the survey. (Waypoint Inertial Explorer v.8.6 POSPac MMS v7.1 SP3)

Calculate laser point position by associating SBET position to each laser point return time, scan angle, intensity, etc. Create raw laser point cloud data for the entire survey in *.las (ASPRS v. 1.2) format. Convert data to orthometric elevations by applying a geoid correction. (RiProcess v1.7.2 Waypoint Inertial Explorer v.8.6 TerraMatch v.17 )

Import raw laser points into manageable blocks (less than 500 MB) to perform manual relative accuracy calibration and filter erroneous points. Classify ground points for individual flightlines. (TerraScan v.17)

Using ground classified points per each flightline, test the relative accuracy. Perform automated line-to-line calibrations for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Calculate calibrations on ground classified points from paired flightlines and apply results to all points in a flightline. Use every flightline for relative accuracy calibration. (TerraMatch v.17 RiProcess v1.7.2 )

Apply refraction correction to all subsurface returns. (LAS Monkey 2.2.6 (QSI proprietary) )

Classify resulting data to ground and other client designated ASPRS classifications. Assess statistical absolute accuracy via direct comparisons of ground classified points to ground control survey data. (TerraScan v.17 TerraModeler v.17)

Generate bare earth models as triangulated surfaces. Generate highest hit models as a surface expression of all classified points. Export all surface models as ESRI GRIDs at a 1 meter pixel resolution. (TerraScan v.17 TerraModeler v.17 ArcMap v. 10.2.2 )

Correct intensity values for variability and export intensity images of all returns as GeoTIFFs at a 0.5 meter pixel resolution. (ArcMap v. 10.2.2 Las Product Creator 1.5 (QSI proprietary))

NOAA/OCM received the data from DOGAMI in LAZ format . Data were in NAD83(2011) UTM zone 10N and NAVD88 (Geoid12a) vertically. All units were meters. For ingest into the Digital Coast Data Access Viewer data were converted to geographic coordinates on the GRS80 ellipsoid in meters.