49633 atm2002_VA-MD_m6305_metadata Data Set Published / External 49401 Lidar - partner (no harvest) Project Completed 2017-08-15 This data set includes data collected in May, 2002, and covers coastline in Virginia and Maryland. Laser beach mapping uses a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation and coastal topography. The laser emits laser beams at high frequency and is directed downward at the earth's surface through a port opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The aircraft travels over the beach at approximately 60 meters per second while surveying from the low water line to the landward base of the sand dunes. The ATM system is a single return green laser and water returns are from the surface. A significant amount of the flight lines from this data set are over water. Original contact information: Contact Org: NOAA Office for Coastal Management Phone: 843-740-1202 Email: coastal.info@noaa.gov This data was collected as part of an effort to map beach topography and assess beach change along the US coastline. 10277 This data set was collected with a lidar (Light Detection And Ranging) instrument designed and developed by the Observational Sciences Branch (OSB) of NASA at the Wallops Flight Facility in Virginia. The instrument, originally designed for mapping ice sheets in Greenland, is called the Airborne Topographic Mapper or ATM. The ATM II (the latest version), operates with a Spectra Physics laser transmitter, which provides a 7 nanoseconds long, 250 microjoules pulse at a frequency-doubled wavelength of 523 nanometers in the blue-green spectral region. The laser transmitter can function at pulse rates from 2 to 10 kilohertz (kHz). The laser system with a separate cooling unit weighs approximately 45 kilograms (kg) and requires approximately 15 amperes of power at 115 volts. The transmitted laser pulse is reflected to the surface of the earth with the aid of a small folding mirror mounted on the back of a secondary mirror of a rotating scan mirror assembly mounted directly in front of the telescope. The scan mirror, which is rotated at 20 hertz, is comprised of a section of round aluminum stock, machined to a specific off-nadir angle. A scan mirror with the off-nadir angle of 15 degrees was utilized, producing an elliptical scan pattern with a swath width equal to 50 percent of the approximately 700-meter aircraft altitude. The reflected laser pulse is transmitted to a photo-multiplier assembly that consists of a lens, a narrow bandpass filter, and a single photomultiplier tube. Note: The Spatial Reference section of this document may lack fully FGDC-compliant information regarding projection parameters (i.e., Central meridian, false Northing, etc.). The State Plane or UTM Zone will be supplied, and the corresponding parameters can be found in Appendix C of: Snyder, John, 1987, Map Projections, a Working Manual (U.S. Geological Survey Professional Paper 1395): Washington, U.S. Government Printing Office. Theme ISO 19115 Topic Category elevation Theme beach Theme erosion Office for Coastal Management Charleston SC Data Set None Planned This data was collected for the purposes of research. Any conclusions drawn from analysis of this information are not the responsibility of NOAA, the Office for Coastal Management, or its partners. Airborne Topographic Mapper LIDAR data were collected in partnership with the the NASA Wallops Flight Facility and the U. S. Geological Survey (USGS) Center for Coastal and Regional Marine Geology. Data Steward 2017-08-15 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 2017-08-15 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 2017-08-15 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 2017-08-15 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 -75.5578 -75.0367 38.4385 37.8419 Discrete 2002-05-06 Yes Unclassified This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer. The data set is dynamically generated based on user-specified parameters. ; None This data was collected for the purposes of research. Any conclusions drawn from analysis of this information are not the responsibility of NASA, USGS, NOAA or the Office for Coastal Management. This data is likely to contain returns from the water surface and vegetation. No processing has been done to remove returns from water or vegetation. 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. https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6305 Customized Download Create custom data files by choosing data area, product type, map projection, file format, datum, etc. https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/6305/index.html Bulk Download Simple download of data files. https://coast.noaa.gov Online Resource https://coast.noaa.gov/dataviewer Online Resource 2017-10-27 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. Raw elevation measurements have been determined to be vertically accurate to within 15 cm. Processing steps (datum conversion, projection, grid interpolation, etc.) introduce additional error factors which have not been tested at the time of this publication. The ATM LIDAR elevation points are known to be horizontally accurate to +/- 0.8 meters at an aircraft altitude of 700 meters. The ATM LIDAR elevation measurements have been found to be within +/- 15 centimeters of each other in successive and overlapping passes of the same area. In comparisons of LIDAR data for a small geographic region with various ground surveys the differences are between +/- 15 to 20 centimeters. The accuracy of the majority of the data is estimated to be consistent with the above stated results. At this time, there has been no large scale verification of the data. All elevation data points that appeared to be within a reasonable vertical range were retained. Not applicable 1 This data was converted from the original NASA Qfit file format into LAS 1.2 using Global Mapper software by USGS. The data was received by NOAA from USGS in March 2017. NOAA compressed the data to LAZ format and modified the georeferencing tags to reflect ITRF2000 as the coordinate reference system with ellipsoid heights instead of generic WGS84. This change was based on discussion with USGS regarding the correct reference system. This metadata record was also created by NOAA as one was not provided by USGS. gov.noaa.nmfs.inport:49633 Anne Ball 2017-11-15T15:21:19 SysAdmin InPortAdmin 2022-08-09T17:11:37 2022-03-16 OCM Partners OCMP 1002 Public No No 2022-03-16 1 Year 2023-03-16