2007 Sumpter Powder River Mine Lidar

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Simple download of data files.

This graphic shows the lidar coverage for the Sumpter, Oregon collected in 2007.

Date that the source FGDC record was last modified.

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Partial upload of Positional Accuracy fields only.

Partial upload to move data access links to Distribution Info.

Acquisition.

The LiDAR survey utilized a Leica ALS50 Phase II mounted in Cessna Caravan 208B. The full

survey was conducted September 17, 2007.

The Leica ALS50 Phase II system was set to acquire =105,000 laser pulses per second (i.e. 105

kHz pulse rate) and flown at 800 meters above ground level (AGL), capturing a scan angle of

plus\minus 14o from nadir2. These settings are developed to yield points with an average native density

of =8 points per square meter over terrestrial surfaces. The native pulse density is the number

of pulses emitted by the LiDAR system. Some types of surfaces (i.e., dense vegetation or

water) may return fewer pulses than the laser originally emitted. Therefore, the delivered

density can be less than the native density and lightly variable according to distributions of

terrain, land cover and water bodies.

1. Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and

static ground GPS data.

2. Develop a smoothed best estimate of trajectory (SBET) file that blends the post-processed

aircraft position with altitude.

3. Calculate laser point position by associating the SBET position to each laser point return

time, scan angle, intensity, etc. Creates raw laser point cloud data for the entire survey in

*.las.

4. Import raw laser points into manageable blocks (less than 500 mb) to perform manual relative

accuracy calibration and filter for pits/birds. Ground points are then classified for individual

flights lines (to be used for relative accuracy testing and calibration).

5. Using ground classification points per each flight line, the relative accuracy is tested.

Automated line-to-line calibrations are then performed for system attitude parameters (pitch, roll,

heading), mirror flex (scale) and GPS/IMU drift. Calibrations are performed on ground classified

points from paired flights lines. Every flight line is used for relative accuracy calibration.

6. Position and attitude data are imported. Resulting data are classified as ground and

non-ground points. Statistical absolute accuracy is assessed via direct comparisons of ground

classified points to ground RTK survey data. Data are then converted to orthometric elevations

(NAVD88) by applying a Geoid03 correction. Ground models are created as a triangulated surface

and exported as ArcInfo ASCII grids at a 1-meter pixel resolution.

The NOAA Office for Coastal Management (OCM) downloaded topographic files in LAZ format from the Puget Sound Lidar Consortium's (PSLC) website. The files contained lidar easting, northing, elevation, intensity, return number, class, scan angle and GPS time measurements; the data was received in UTM Zone 11 (in meters) and vertical coordinates were referenced to NAVD88 in meters using the Geoid03 model.

OCM performed the following processing for data storage and Digital Coast provisioning purposes:

1. The All-Return LAZ files were checked for bad elevations

2. The laz files were converted from a Projected Coordinate System (UTM Zone 11) to a Geographic Coordinate system (NAD83)

3. The laz files were then converted to ellipsoidal vertical units in meters.