49628 ak2013_cbj_juneau_m4813_metadata Data Set Published / External 49401 Lidar - partner (no harvest) Project Completed 2015-03-10 This dataset is LiDAR point cloud data, which encompasses a 100 meter buffer around the Juneau,AK study area, approximately 121,313 acres. Dataset Description: This dataset consists of 1273 .LAS files delineated in 750 x 750 m tiles and named as specified by the client. Each .LAS file contains LiDAR point information, which has been calibrated, controlled, and classified. LAS points contain RGB values from orthoimagery mosaics. Normalized intensity values are represented in the intensity field in this version of the point cloud. Ground Conditions: LiDAR acquisition of near shore areas was prioritized to coincide with the lowest tides possible, within constraints of daily local weather patterns. Leaf-off, no snow conditions were targeted in all other areas given the diverse terrain represented in the study area. The LAZ files have vertical georeferencing using the EPSG 5866 code for mean lower low water. However, this code is for depth while the data is in height. There was no appropriate code for MLLW height at the time. Data was collected to aid CBJ in assessing the topographic and geophysical properties of the study area to support municipal planning, habitat assessments, and general development in the region. The LiDAR point cloud data were used to create classified LiDAR LAS files, normalized intensity images, 3D breaklines, bare earth DEM, bare earth hydro-flattened DEM, High Hit DSM, Vegetation height model, bridge footprints, 0.5m contours, and a mean high water contour. Data were also used to rectify 4-band orthophotos. The contract for this project was funded by the Coastal Impact Assistance Program through the Alaska Department of Commerce, Community, and Economic Development as part of Grant # 10-CIAP-0009, titled 'Habitat Mapping and Analysis Project.' All processing was completed by WSI. In some areas of heavy vegetation or forest cover, there may be relatively few ground points in the LiDAR data. TINing the points produces large triangles and hence the elevations may be less accurate within such areas. Elevation values for open water surfaces are derived from waters edge breaklines. Triangles were created across water surfaces by interpolating from the nearest breakline elevation points. RandM Engineering Inc. (Mark A. Johnson - AKPLS#7570) provided the Mean Lower Low Water (MLLW) elevation adjustment for all monuments used for the project. These MLLW elevations were determined by running level loops from tidal benchmarks with published MLLW elevations to each monument. Differences between the orthometric elevations of each monument on Geoid 12A and the MLLW elevations can be found in Appendix B of the Juneau LiDAR data report. The average MLLW adjustment was approximately 1.045m with a standard deviation of 0.066m. As a result of being calibrated using the ellipsoidal MLLW elevations instead of the normal ellipsoidal elevations, the LiDAR data was adjusted to the MLLW vertical datum. 10272 Theme ISO 19115 Topic Category elevation Spatial Global Change Master Directory (GCMD) Location Keywords VERTICAL LOCATION > LAND SURFACE Instrument Global Change Master Directory (GCMD) Instrument Keywords LIDAR > Light Detection and Ranging Platform Global Change Master Directory (GCMD) Platform Keywords Airplane > Airplane Office for Coastal Management Charleston SC Data Set None Planned las LAS 1.2 format (classes 2,3,4,5,6,7,8,9,10,19,20,21,22,23,24,25,27) none Any conclusions drawn from the analysis of this information are not the responsibility of RandM Engineering Inc., Watershed Sciences Inc (Quantum Spatial), Alaska DGGS, NOAA, the Office for Coastal Management or its partners. Data Steward 2015-03-10 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Distributor 2015-03-10 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Metadata Contact 2015-03-10 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Point of Contact 2015-03-10 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Ground Condition -135.155767 -133.665411 58.895525 58.043303 Range 2013-05-08 2013-06-11 Yes Yes 5279631270 Geographic 2D EPSG:6318 NAD83(2011) NAD83 (National Spatial Reference System 2011) GRS 1980 6378137 298.257222101 1 Geodetic Lattitude Lat degree north 2 Geodetic Longitude Lon degree east Vertical EPSG:5866 MLLW depth Mean Lower Low Water 1 Depth D metre down Unclassified This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4813 The data set is dynamically generated based on user-specified parameters.; No restrictions apply to this data. In some areas of heavy vegetation or forest cover, there may be relatively few ground points in the LiDAR data. TINing the points produces large triangles and hence the elevations may be less accurate within such areas. Elevation values for open water surfaces are derived from waters edge breaklines. Triangles were created across water surfaces by interpolating from the nearest breakline elevation points. RandM Engineering Inc. (Mark A. Johnson - AKPLS#7570) provided the Mean Lower Low Water (MLLW) elevation adjustment for all monuments used for the project. These MLLW elevations were determined by running level loops from tidal benchmarks with published MLLW elevations to each monument. Differences between the orthometric elevations of each monument on Geoid 12A and the MLLW elevations can be found in Appendix B of the Juneau LiDAR data report. The average MLLW adjustment was approximately 1.045m with a standard deviation of 0.066m. As a result of being calibrated using the ellipsoidal MLLW elevations instead of the normal ellipsoidal elevations, the LiDAR data was adjusted to the MLLW vertical datum. Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. These data depict the heights at the time of the survey and are only accurate for that time. https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4813 2015-03-10 Organization NOAA Office for Coastal Management Customized Download Create custom data files by choosing data area, product type, map projection, file format, datum, etc. Zip Zip https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/entwine/mllw/4813/ept.json 2015-03-10 Organization NOAA Office for Coastal Management ept.json Data in Entwine Point Tile format suitable for streaming. EPT https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/mllw/4813/index.html 2015-03-10 Organization NOAA Office for Coastal Management Bulk Download Simple download of data files. LAZ LAS/LAZ - LASer Zip https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/mllw/4813/supplemental/ak2013_cbj_juneau_m4813.kmz Browse Graphic Browse Graphic kmz This graphic shows the lidar coverage for the 2013 lidar project covering Juneau County, Alaska. https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/mllw/4813/supplemental/ak2013_cbj_juneau_m4813_surveyreport.pdf Project report Online Resource pdf Project report from the lidar contractor 2017-04-04 Date that the source FGDC record was last modified. 2017-11-14 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. 2018-02-08 Partial upload of Positional Accuracy fields only. 2018-03-13 Partial upload to move data access links to Distribution Info. The cumulative orthophoto horizontal accuracy (RMSE) for the Juneau Priority Area 1 was 0.55 feet (0.17 meters) measured by ground control points and 0.30 feet (0.09 meters) measured by air targets, meeting our accuracy standard of < 3 pixels (0.45 meters); Quantitative Value: 0.17 meters, Test that produced the value: The cumulative orthophoto horizontal accuracy (RMSE) for the Juneau Priority Area 1 was 0.55 feet (0.17 meters) measured by ground control points and 0.30 feet (0.09 meters) measured by air targets, meeting our accuracy standard of < 3 pixels (0.45 meters) Specifications for this project require that the FVA be 24.5 cm or better AccuracyZ at 95 percent confidence level.; Quantitative Value: 0.059 meters, Test that produced the value: 5.9 cm meters AccuracyZ at 95 percent Confidence Interval. Accuracy was assessed using 3095 ground survey RTK (real time kinematic) points. ; Quantitative Value: 0.072 meters, Test that produced the value: Bare Earth SVA; Quantitative Value: 0.236 meters, Test that produced the value: Brush SVA; Quantitative Value: 0.122 meters, Test that produced the value: Deciduous Forest SVA; Quantitative Value: 0.127 meters, Test that produced the value: Evergreen Forest SVA; Quantitative Value: 0.131 meters, Test that produced the value: Short Grass SVA; Quantitative Value: 0.106 meters, Test that produced the value: Wetland Grass SVA LAS files include all data points collected. No points have been removed or excluded. Shaded relief images have been visually inspected for data errors such as pits, border artifacts, and shifting. LiDAR flight lines have been examined to ensure consistent elevation values across overlapping flight lines. The raw point cloud is of good quality and data passes Fundamental Vertical Accuracy specifications. Please see the LiDAR data report for a discussion of the statistics related to this dataset. Data cover the entire area specified for this project. 1 LiDAR Pre-Processing: 1. Flight lines and data were reviewed to ensure complete coverage of the study area and positional accuracy of the laser points. 2. Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data. 3. Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with attitude data. Sensor head position and attitude are calculated throughout the survey. The SBET data are used extensively for laser point processing. 4. 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. Data are converted to orthometric elevations (NAVD88) by applying a Geoid12a correction. 5. Import raw laser points into manageable blocks (less than 500 MB) to perform manual relative accuracy calibration and filter erroneous points. Ground points are then classified for individual flight lines (to be used for relative accuracy testing and calibration). 6. Using ground classified 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 calculated on ground classified points from paired flight lines and results are applied to all points in a flight line. Every flight line is used for relative accuracy calibration. 7. Assess statistical absolute accuracy via direct comparisons to ground RTK survey data. 2013-09-30T00:00:00 2 LiDAR Post-Processing: 1. Classify data to ground and other client designated classifications using proprietary classification algorithms. 2. Manually QC data classification 3. Normalize Intensity Values for receiver auto gain control, atmospheric effects, and angle of incidence. 4.Apply RGB values from orthophotos to points. 2013-09-30T00:00:00 3 The NOAA Office for Coastal Management (OCM) received the files in laz format from USGS via an FTP online repository. The files contained lidar elevation and intensity measurements. The data were in UTM Zone 5, mean lower low water heights in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. The data were converted from UTM coordinates to geographic coordinates. 2. Duplicate points were removed 2022-09-13T00:00:00 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource gov.noaa.nmfs.inport:49628 Anne Ball 2017-11-15T15:21:17 SysAdmin InPortAdmin 2023-10-17T16:12:16 2022-09-14 OCM Partners OCMP 1002 Public No No 2022-03-16 1 Year 2023-03-16