Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) 20110531 digital data http://www.soest.hawaii.edu/pibhmc/ http://www.soest.hawaii.edu/pibhmc/pibhmc_cnmi_gal_backscat.htm Multibeam backscatter imagery extracted from gridded bathymetry of the Mariana archipelago between the U.S. Territory of Guam and Farallon De Pajaros Island in the Commonwealth of the Northern Mariana Islands. These data provide coverage between 0 and -300 meters. The backscatter datasets includes data collected using the Reson 8101 multibeam sonar. The sonars frequency is 240 kHz. These metadata are for the 1 m grid cell size Reson 8101 multibeam backscatter data only. The GeoTIFFs and netCDF grids of backscatter imagery were created using data gathered from multibeam soundings for use as a planning and reference document. The data are also being used for benthic habitat mapping, for locating Essential Fish Habitat, and for studying geologic features of the area. Refer to supplemental information for description of instrument and survey. Multibeam data were collected aboard the R/V AHI (Acoustic Habitat Investigator), a 25' survey launch owned and operated by the NOAA Pacific Islands Fisheries Science Center in Honolulu, Hawaii. The R/V AHI's survey sensors include a 240 kHz Reson 8101-ER sonar providing multibeam bathymetry and backscatter data, a TSS/Applanix POS/MV Model 320 which measures position, velocity, attitude and heading, and a Seabird SBE 19 CTD used to measure sound velocity profiles. Additional data were collected aboard the NOAA Ship Oscar Elton Sette, a 224'(68 m) United States National Oceanographic and Atmospheric Administration research ship. The NOAA Ship Sette's survey sensors included a 240-kHz pole- mounted Reson 8101ER sonar, which provides multibeam bathymetry and backscatter imagery data, a TSS/Applanix POS/MV Model 320, which measures position, velocity, attitude and heading, and a Seabird SBE19 CTD used to measure sound velocity profiles. Specific equipment configurations are documented in metadata from cruises: AHI0702, SE1002. These metadata can be accessed at: http://www.soest.hawaii.edu/pibhmc/pibhmc_cruise-catalog.htm. 2010 2010 ground condition Complete As needed 144.42 144.49 13.11 13.02 None Acoustic Imagery Multibeam Backscatter Backscatter CoRIS Theme Thesaurus EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Backscatter ISO 19115 Topic Category oceans 014 imageryBaseMapsEarthCover 010 CoRIS Discovery Thesaurus Geographic Information > Backscatter None UTM zone 55 U.S. Territory of Guam Commonwealth of the Northern Mariana Islands United States of America CoRIS Place Thesaurus OCEAN BASIN > Pacific Ocean > Western Pacific Ocean > Guam > Guam (13N144E0000) COUNTRY/TERRITORY > United States of America > Guam > Guam (13N144E0000) OCEAN BASIN > Pacific Ocean > Western Pacific Ocean > Guam > Galvez Bank (13N144E0049) COUNTRY/TERRITORY > United States of America > Guam > Galvez Bank (13N144E0049) CoRIS Region Guam none These data are not to be used for navigation purposes. Please acknowledge NOAA and the Joint Institute for Marine and Atmospheric Research (JIMAR) University of Hawaii as the sources of this information. Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) mailing and physical address

1125B Ala Moana Blvd.

Honolulu HI 96814 (808) 983-3776 (808) 983-2902 pibhmc@soest.hawaii.edu e-mail preferred http://www.soest.hawaii.edu/pibhmc/CNMI_images/Gal_1m_bs_450.jpg Multibeam Backscatter JPEG PIBHMC, CRED, PIFSC, NOAA and JIMAR Not applicable Unclassified Not applicable GeoTIFF and netCDF grid file created using HMRG software in a LINUX environment Data are collected for resource management and research purposes and are tested for internal consistency; however, no effort is made to compare these data to external references or to other published data. These data are believed to be logically consistent though no tests were performed. Complete Horizontal positioning system: GPS (SPS) Horizontal position accuracy: 25 meters 1 m Range resolution of sonar ~1.25 cm Raw sounding resolution: Variable Vertical accuracy of gridded product: 1% of water depth Science Applications International Corporation's (SAIC)ISS-2000 acquires, processes and records data, provides survey control and underway quality control displays. SAIC's SABER processing software is used to process the raw soundings, analyze the results, manually edit the sounding data to remove outliers and derive average gridded data values. Additional data acquisition and processing information can be found in the metadata for cruises AHI0702 and SE1002. Hawaii Mapping Research Group (HMRG) processing software was then used to extract values of acoustic intensity from the soundings. HMRG is an organization of scientists, engineers and technicians whose mission is to design, build, and operate tools for mapping the seafloor. HMRG is a group within the School of Ocean and Earth Science and Technology at the University of Hawaii at Manoa. The gsf2bs program (July, 2005) converts the swath bathymetry ping records contained within a GSF (Generic Sensor Format) version 2.02 dataset into bs file format. This is done as follows: (i) position each beam's bottom detect intensity sample at the across-track location of that beam's bathymetry value; (ii) assuming a flat bottom in the near neighborhood of the beam, compute across- track distances for all of the beam's remaining intensity samples based on their temporal relation to the bottom detect sample and the computed average sound velocity for that beam as derived from its range and travel time; (iii) after all of the intensity samples from all beams of a ping have been located in across-track distance, fill the gaps between them as necessary by comparing travel times of beams adjacent to the gap, assigning the position using the adjacent sample closest to nadir, and averaging the interpolated values that fall within a cell. The conversion described above is necessary in order to run HMRG backscatter processing operations on the data, such as filtering to remove noise, and to create netCDF grids, raster images and GeoTIFF's. For more information on the backscatter processing technique see <http://www.soest.hawaii.edu/pibhmc/pibhmc_documentation.htm>. Software Used: SAIC ISS-2000 Acquisition Software, v 3.4, SAIC SABER Processing Software, v 4.4.16, Hawaii Mapping Research Group (HMRG) Processing Software, Generic Mapping Tools (GMT), v 4.2, MB System, v 5.1 20110220 Raster Grid Cell 6520 7668 1 Universal Transverse Mercator 55 0.9996 147 0 500000 0 Row and Column 1 1 meters D_WGS_1984 WGS_1984 6378137.000000 298.257224 mean lower low water 0.01 meters Attribute Values Sidescan data within a GSF file are arranged as small sequences of intensity values, one sequence per beam per ping. The intensity values represent the amplitude of echo returns to the sensor and can be related to seabed roughness. none Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) mailing and physical address

1125B Ala Moana Blvd.

Honolulu HI 96814 (808) 983-3776 (808) 983-2902 pibhmc@soest.hawaii.edu e-mail preferred Downloadable Data These data are not to be used for navigational purposes. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system. GeoTIFF, .tif TIFF is a format for storage, transfer, display, and printing of raster images. The TIFF file structure allows both the tag and the image data to be encoded into the same file. GeoTIFF refers to a TIFF file that has geographic data embedded as tags within the TIFF file. The geographic data can be used to position the image in the correct location and geometry on the screen of a geographic information display. Any GIS, CAD, Image Processing, Desktop Mapping and other types of systems using geographic images can read any GeoTiff file. More specifically, files of this type can be added to ArcInfo and ArcView 8.x or higher and may be viewed in the Table of Contents as a new raster layer. Image visualization software that does not use geography as a basis for image placement can view a GeoTIFF image as if there were no geographic information in the TIFF file. For example, GeoTIFF files can be viewed using Windows Picture and Fax viewer. The GeoTIFF format is public domain, non- proprietary. List of Reson 8101 backscatter files and bounding coordinates: galvez-8101-8-01 W/E/S/N: 144.42/144.49/13.10/13.12 galvez-8101-8-02 W/E/S/N: 144.41/144.48/13.01/13.07 galvez-8101-8-04 W/E/S/N: 144.37/144.44/12.97/13.03 galvez-8101-8-05 W/E/S/N: 144.42/144.50/13.20/13.26 none ftp://ftp.soest.hawaii.edu/pibhmc/website/data/cnmi-guam/backscatter/Gal_1m_backscat.zip None 20121220 20110810 Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) mailing and physical address

1125B Ala Moana Blvd.

Honolulu HI 96814 (808) 983-3776 (808) 983-2902 pibhmc@soest.hawaii.edu e-mail preferred FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 Universal Time None None 20110810034428 None 20100101 20101231 http://www.coris.noaa.gov/metadata/records/html/maramp_gal_8101_bs_1m.html 6349