Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG), Menlo Park, CA. Publication_Date: 2010 Title: mb_nad83_amp1 Edition: 1 Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: http://pubs.usgs.gov/ds/514/ Description: Abstract: USGS Western Coastal & Marine Geology scientists mapped the Monterey Bay area from Ano Nuevo to Moss landing between August and December 2009 using a SEA SWATHplus interferometric sonar system. Data were collected as part of the cooperative California Seafloor Mapping program, during field activities S-7-09-MB and S-10-09-MB. Backscatter was normalized for the survey area and gridded to 2m resolution. This is a preliminary GEOTIFF product produced by mosaicing 2m gridded backscatter data from each survey line into a single raster and interpolating using a rectangular 3x3 focalmean algorith in ArcGIS. Purpose: California State Waters Mapping Supplemental_Information: Information about August-September 2009 field activity data collection at . Information about October - December field activity data collection at . Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20090813 Ending_Date: 20091222 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -122.338215 East_Bounding_Coordinate: -122.099598 North_Bounding_Coordinate: 37.111178 South_Bounding_Coordinate: 36.862544 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificinformation Theme_Keyword: oceans Theme: Theme_Keyword_Thesaurus: USGS CMG InfoBank Theme_Keyword: geoscientific information Theme_Keyword: backscatter Theme_Keyword: oceans Theme_Keyword: Marine Geology Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Ano Nuevo Place_Keyword: Moss Landing Place_Keyword: Monterey Bay Place_Keyword: California Place_Keyword: Pacific Ocean Place: Place_Keyword_Thesaurus: USGS CMG InfoBank Place_Keyword: "Monterey Bay, CA" Place_Keyword: CA Place_Keyword: Monterey Bay Place_Keyword: Moss Landing to Ano Nuevo Place_Keyword: North Pacific Ocean Place_Keyword: Northern California Place_Keyword: Northern Pacific Ocean Place_Keyword: USA Access_Constraints: If physical samples or materials are available, constraints on their on-site access are described in "WR CMG Sample Distribution Policy" at URL: http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html Use_Constraints: Not suitable for navigation Read and fully comprehend the metadata prior to data use. Acknowledge the U.S. Geological Survey (USGS), the Originator, when using the data set as a source. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Share data products developed using the source data set with the Originator. Data should not be used beyond the limits of the source scale. This information is not intended for navigational purposes. The data set is NOT a survey document and should not be utilized as such. Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Western Coastal & Marine Geology Contact_Person: Guy Cochrane Contact_Position: Geophysicist Contact_Address: Address_Type: physical address Address: 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95062 Country: USA Contact_Voice_Telephone: (831) 427-4754 Contact_Facsimile_Telephone: (831) 427-4748 Contact_Electronic_Mail_Address: gcochrane@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: http://walrus.wr.usgs.gov/infobank/s/s709mb/html/s-7-09-mb.index.png Browse_Graphic_File_Description: Illustration of ship tracklines for data collection field activity S-7-09-MB. Browse_Graphic_File_Type: PNG Browse_Graphic: Browse_Graphic_File_Name: http://walrus.wr.usgs.gov/infobank/s/s1009mb/html/s-10-09-mb.index.png Browse_Graphic_File_Description: Illustration of ship tracklines for data collection field activity S-10-09-MB. Browse_Graphic_File_Type: PNG Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3500 Data_Quality_Information: Logical_Consistency_Report: These are raw data with uninterpreted results. for updated on this dataset, search for cruise S-7-09-MB and S-10-09-MB on USGS Coastal & Marine Geology InfoBank, or email: dfinlayson@usgs.gov. Completeness_Report: GPS Data Collection and Processing Bathymetric surveys were conducted using a 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. The sonar was pole-mounted on the 34-foot USGS mapping vessel R/V Parke Snavely. The R/V Snavely was equipped with a CodaOctopus F180 attitude and position system for the duration of the survey. The F180 is running F190 firmware, and receives real-time kinematic (RTK) corrections directly. The RTK GPS data (2 cm error ellipse) are combined with the inertial motion measurements directly within the F190 hardware so that high-precision position and attitude corrections are fed in real-time to the sonar acquisition equipment. The WGS84 (G1150) Epoch 2002.0 3-dimensional reference frame was used for all measurements. GPS data and measurements of vessel motion are combined in the F180 hardware to produce a high-precision vessel attitude packet. This packet is transmitted to the Swath Processor acquisition software in real-time and combined with instantaneous sound velocity measurements at the transducer head before each ping. Up to 20 pings per second are transmitted with each ping consisting of 2048 samples per side (port and starboard). Sound Velocity Measurements Sound velocity profile (SVP) measurements were collected on average every two hours throughout the survey. A total of 440 SVPs were collected for this survey. 114 SVPs were collected during cruise S-7-09-MB and 326 SVPs were collected during S-10-09-MB. In general, SVPs were collected every 2 hours, or when the survey vessel moved to a different survey block. Typically two SVPs were collected every four lines. Water column sound velocity profiles varied significantly throughout the survey, however this frequency of SVP collection was sufficient to correct for variations in sound velocity. Only one line from cruise S-7-09-MB (BlockA_230_044) shows an artifact from an uncorrected sound velocity error (smile), for part of it's length. Insufficient sound velocity data were available to correct this line, and no attempt was made to synthesize data. SVPs were collected with an Applied Micro Systems, SvPlus 3472. This instrument provides time-of-flight sound velocity measurements using invar rods with a sound velocity accuracy of +/- 0.06 m/s, pressure measured by a semiconductor bridge strain gauge to an accuracy to 0.15% (Full Scale) and temperature measured by thermistor to an accuracy of 0.05 C (Applied Microsystems Ltd., 2005). In addition, an Applied Micro Systems Micro SV accurate to +/- 0.03 m/s was deployed on the transducer frame for real-time sound velocity adjustments at the transducer-water interface. The returned samples are projected to the lake bottom using a ray-tracing algorithm working with measured sound velocity profiles in SEA Swath Processor (version 3.05.18.04). A series of statistical filters are applied to the raw samples that isolate the lake bottom returns from other uninteresting targets in the water column. Finally, the processed x,y,z, amplitude data is stored line-by-line in both raw (.sxr) and processed (.sxp) trackline files. For this cruise, processed files were filtered across-track with a mean filter at 0.5m resolution. Bathymetry Processing Processed (.sxp) files were run through sxpegn (build 151) by David Finlayson (USGS) to remove erroneous data from the files and make valid gain-normalized amplitude data for CARIS HIPS and SIPS (version 7.0.1.0 Service Pack 1) Processed .sxp files were imported to CARIS, and field sheets were created within CARIS and defined to the nearest even integer meter in ground coordinates (WGS84(G1150) UTM Zone 10), to approximately match CA State Waters Quads 36 - 41. Because quads 38 & 39, and quads 40 & 41 had very little horizontal overlap, a horizontal overlap was added to the eastern quads in both cases; that is, the western bounds of quads 39 and 41 were extended to create overlap between field sheets. Survey line width were filtered (trimmed) in CARIS to remove adjacent line data from nadir gaps. Target overlap between lines was 25 - 30%, though values ranged from ~10% to <50% depending on line spacing and data quality. CARIS Swath Angle BASE surfaces were then created for each map block at 2m resolution, and the subset editor was used to examine each field sheet and clean artifacts from biological targets and other unwanted soundings. Cleaned data were exported in Generic Sensor Format (GSF). Amplitude Processing Amplitude values are co-registered with bathymetry data. xy amplitude values were normalized by range using the entire cruise dataset by processing with sxpegn (build 151), nadir gaps were filled using sxpmagic (build 44) to interpolate amplitude values near-nadir to the nadir. Both pieces of software were developed by David P. Finlayson (USGS CMG, Santa Cruz, CA). Normalized, nadir-filled amplitude data were gridded by line at 2m resolution using SEA Grid Processor (version 3.0.18.04) and exported as x,y, amplitude files. Files were imported as multipoint feature classes to a file geodatabase in ArcGIS 9.3.1 using the 3D Analyst ASCII 3D to Feature Class tool. Each line was then converted to a raster. For each survey block, Individual lines were mosaicked to a new raster using the ArcGIS BLEND algorithm. Blocks were then mosaicked together with the same algorithm to create a 2m raster for the entire project area. One interpolation pass was used to fill gaps in the dataset with a 3x3 focalmean function. The data were then exported as a 16-bit unsigned integer GeoTIFF, and a worldfile was generated from the GeoTIFF properties. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Accuracy should be on the order of 2 meters due to datum transformations and grid cell size. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey, Coastal and Marine Geology Program Publication_Date: 2009 Title: USGS CMG S-7-09-MB Metadata Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: http://walrus.wr.usgs.gov/infobank/s/s709mb/html/s-7-09-mb.meta.html Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20090813 Ending_Date: 20090903 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: S-7-09-MB Source_Contribution: Cruise S-7-09-MB contributed swath mapping data from Point Ano Nuevo to Table Rock, and a block near Soquel Canyon, in Monterey Bay National Marine Sanctuary. These data are primarily the western 1/3 of the survey area. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey, Coastal and Marine Geology Program Publication_Date: 2009 Title: USGS CMG S-10-09-MB Metadata Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: http://walrus.wr.usgs.gov/infobank/s/s1009mb/html/s-10-09-mb.meta.html Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20091012 Ending_Date: 20091126 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: S-10-09-MB Source_Contribution: Cruise S-10-09-MB contributed swath mapping data to this survey from Table rock to Moss Landing, in Monterey Bay National Marine Sanctuary. This comprised approximately the eastern 2/3 of the survey area. Process_Step: Process_Description: Data Collection and Processing Bathymetric surveys were conducted using a 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. The sonar was pole-mounted on the 34-foot USGS mapping vessel R/V Parke Snavely. The R/V Snavely was equipped with a CodaOctopus F180 attitude and position system for the duration of the survey. The F180 is running F190 firmware, and receives real-time kinematic (RTK) corrections directly. The RTK GPS data (2 cm error ellipse) are combined with the inertial motion measurements directly within the F190 hardware so that high-precision position and attitude corrections are fed in real-time to the sonar acquisition equipment. The WGS84 (G1150) Epoch 2002.0 3-dimensional reference frame was used for all measurements. GPS data and measurements of vessel motion are combined in the F180 hardware to produce a high-precision vessel attitude packet. This packet is transmitted to the Swath Processor acquisition software in real-time and combined with instantaneous sound velocity measurements at the transducer head before each ping. Up to 20 pings per second are transmitted with each ping consisting of 2048 samples per side (port and starboard). Sound Velocity Measurements Sound velocity profile (SVP) measurements were collected on average every two hours throughout the survey. A total of 440 SVPs were collected for this survey. 114 SVPs were collected during cruise S-7-09-MB and 326 SVPs were collected during S-10-09-MB. In general, SVPs were collected every 2 hours, or when the survey vessel moved to a different survey block. Typically two SVPs were collected every four lines. Water column sound velocity profiles varied significantly throughout the survey, however this frequency of SVP collection was sufficient to correct for variations in sound velocity. Only one line from cruise S-7-09-MB (BlockA_230_044) shows an artifact from an uncorrected sound velocity error (smile), for part of it's length. Insufficient sound velocity data were available to correct this line, and no attempt was made to synthesize data. SVPs were collected with an Applied Micro Systems, SvPlus 3472. This instrument provides time-of-flight sound velocity measurements using invar rods with a sound velocity accuracy of +/- 0.06 m/s, pressure measured by a semiconductor bridge strain gauge to an accuracy to 0.15% (Full Scale) and temperature measured by thermistor to an accuracy of 0.05 C (Applied Microsystems Ltd., 2005). In addition, an Applied Micro Systems Micro SV accurate to +/- 0.03 m/s was deployed on the transducer frame for real-time sound velocity adjustments at the transducer-water interface. The returned samples are projected to the lake bottom using a ray-tracing algorithm working with measured sound velocity profiles in SEA Swath Processor (version 3.05.18.04). A series of statistical filters are applied to the raw samples that isolate the lake bottom returns from other uninteresting targets in the water column. Finally, the processed x,y,z, amplitude data is stored line-by-line in both raw (.sxr) and processed (.sxp) trackline files. For this cruise, processed files were filtered across-track with a mean filter at 0.5m resolution. Bathymetry Processing Processed (.sxp) files were run through sxpegn (build 151) by David Finlayson (USGS) to remove erroneous data from the files and make valid gain-normalized amplitude data for CARIS HIPS and SIPS (version 7.0.1.0 Service Pack 1) Processed .sxp files were imported to CARIS, and field sheets were created within CARIS and defined to the nearest even integer meter in ground coordinates (WGS84(G1150) UTM Zone 10), to approximately match CA State Waters Quads 36 - 41. Because quads 38 & 39, and quads 40 & 41 had very little horizontal overlap, a horizontal overlap was added to the eastern quads in both cases; that is, the western bounds of quads 39 and 41 were extended to create overlap between field sheets. Survey line width were filtered (trimmed) in CARIS to remove adjacent line data from nadir gaps. Target overlap between lines was 25 - 30%, though values ranged from ~10% to <50% depending on line spacing and data quality. CARIS Swath Angle BASE surfaces were then created for each map block at 2m resolution, and the subset editor was used to examine each field sheet and clean artifacts from biological targets and other unwanted soundings. Cleaned data were exported in Generic Sensor Format (GSF). Amplitude Processing Amplitude values are co-registered with bathymetry data. xy amplitude values were normalized by range using the entire cruise dataset by processing with sxpegn (build 151), nadir gaps were filled using sxpmagic (build 44) to interpolate amplitude values near-nadir to the nadir. Both pieces of software were developed by David P. Finlayson (USGS CMG, Santa Cruz, CA). Normalized, nadir-filled amplitude data were gridded by line at 2m resolution using SEA Grid Processor (version 3.0.18.04) and exported as x,y, amplitude files. Files were imported as multipoint feature classes to a file geodatabase in ArcGIS 9.3.1 using the 3D Analyst ASCII 3D to Feature Class tool. Each line was then converted to a raster. For each survey block, Individual lines were mosaicked to a new raster using the ArcGIS BLEND algorithm. Blocks were then mosaicked together with the same algorithm to create a 2m raster for the entire project area. One interpolation pass was used to fill gaps in the dataset with a 3x3 focalmean function. The data were then exported as a 16-bit unsigned integer GeoTIFF, and a worldfile was generated from the GeoTIFF header information with an AML script. Process_Date: 2009 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Coastal and Marine Geology Program Contact_Person: Andy Ritchie Contact_Address: Address_Type: mailing and physical Address: 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792-5792 Country: US Contact_Voice_Telephone: 831-427-4791 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: aritchie@usgs.gov Process_Step: Process_Description: Coordinate System Transformation To convert the data from the WGS84 (G1150) epoch 2002.0 ellipsoid to NAD83 (CORS96) epoch 2002.0, data were exported from ArcGIS as an ESRI ASCII grid, and converted to an xyz point file in a python script. Next, a 14-parameter Helmert transformation was applied to the data set with time-dependent transformation parameters calculated for January 1, 2002 according to methods outlined in Soler and Snay (2004). Calculations were applied using cs2cs(Version 4.4.6), an open-source program developed as part of the PROJ.4 Library, originally developed by Gerald Evenden while working for the USGS. Changes to the Z (Amplitude) values were discarded. Data were then re-gridded in ArcGIS, and a final NAD83(CORS96) amplitude grid was exported in ESRII ASCII GRID (.ASC) and .TIF formats. Process_Date: 20100407 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 13706 Column_Count: 10506 Vertical_Count: 1 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Transverse Mercator Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999600 Longitude_of_Central_Meridian: -123.000000 Latitude_of_Projection_Origin: 0.000000 False_Easting: 500000.000000 False_Northing: 0.000000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 2.000000 Ordinate_Resolution: 2.000000 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: D_North_American_1983_HARN Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: amplitude_16.vat Entity_Type_Definition: Gain-normalized backscatter. Higher values are higher amplitude backscatter. The files in this archive are 2 meter grids in ESRI ASCII GRID format. Each ASCII Grid was split in two parts to reduce the file size below the 2 gb limit for 32-bit .zip archives. These grids can be reassembled seamlessly in ARC with the mosaic function. NAD 83 grids are in NAD83(CORS96/NSRS2007) epoch 2002.0, UTM Zone 10 N. ArcGIS cannot accurately represent this reference frame. The closest analog appears to be NAD83(HARN) UTM Zone 10N. For most applications it will be sufficient to use the WGS84 and NAD83 UTM Zone 10 projections. ESRI ASCII GRID format: (Copied from the ArcGIS Desktop 9.3 Help File) The ASCII file must consist of header information containing a set of keywords, followed by cell values in row-major order. The file format is: > > > > > > > {NODATA_VALUE xxx} > row 1 > row 2 > . > . > . > row n > where xxx is a number, and the keyword nodata_value is optional and defaults to -9999. Row 1 of the data is at the top of the grid, row 2 is just under row 1 and so on. For example: > > ncols 480 > nrows 450 > xllcorner 378923 > yllcorner 4072345 > cellsize 30 > nodata_value -32768 > 43 2 45 7 3 56 2 5 23 65 34 6 32 54 57 34 2 2 54 6 > 35 45 65 34 2 6 78 4 2 6 89 3 2 7 45 23 5 8 4 1 62 ... > The nodata_value is the value in the ASCII file to be assigned to those cells whose true value is unknown. In the grid they will be assigned the keyword NODATA. Cell values should be delimited by spaces. No carriage returns are necessary at the end of each row in the grid. The number of columns in the header is used to determine when a new row begins. The number of cell values must be equal to the number of rows times the number of columns, or an error will be returned. Entity_Type_Definition_Source: USGS Attribute: Attribute_Label: Rowid Attribute_Definition: Internal feature number. Attribute_Definition_Source: ESRI Attribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated. Attribute: Attribute_Label: VALUE Attribute_Definition: amplitude values Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: Sonar amplitude data values Attribute: Attribute_Label: COUNT Attribute_Definition: For the description of this attribute, contact Andy Ritchie, email: aritchie@usgs.gov. Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: sum of data points Detailed_Description: Entity_Type: Entity_Type_Label: Ampl_Interp.tif.vat Entity_Type_Definition: This is the .TIFF file's internally stored value table name. Entity_Type_Definition_Source: USGS Attribute: Attribute_Label: ObjectID Attribute_Definition: Internal feature number. Attribute_Definition_Source: ESRI Attribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated. Attribute: Attribute_Label: Value Attribute_Definition: These data are processed amplitude values from swath sonar returns, normalized by distance and beam angle for the entire cruise dataset. Higher amplitude returns are represented by higher values. values are 16-bit unsigned integer. Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: Sonar amplitude data values Attribute: Attribute_Label: Count Attribute_Definition: For the description of this attribute, contact Andy Ritchie, email: aritchie@usgs.gov. Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: sum of data points Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Coastal and Marine Geology Program Contact_Person: Andy Ritchie Contact_Address: Address_Type: mailing and physical address Address: 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: US Contact_Voice_Telephone: 831-427-4791 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: aritchie@usgs.gov Resource_Description: Downloadable Data Distribution_Liability: This information is not intended for navigational purposes. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology. Please recognize the U.S. Geological Survey (USGS) as the source of this information. Physical materials are under controlled on-site access. Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: TIFF Transfer_Size: 562.960 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/ds/514/ Fees: none Metadata_Reference_Information: Metadata_Date: 20100504 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Coastal and Marine Geology Program Contact_Person: Andy Ritchie Contact_Address: Address_Type: mailing and physical address Address: 400 Natural Bridges Drive City: Santa Cruz State_or_Province: CA Postal_Code: 95060-5792 Country: US Contact_Voice_Telephone: 831-427-4791 Contact_Facsimile_Telephone: 831-427-4748 Contact_Electronic_Mail_Address: aritchie@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time Metadata_Extensions: Online_Linkage: Profile_Name: ESRI Metadata Profile Metadata_Extensions: Online_Linkage: http://www.esri.com/metadata/esriprof80.html Profile_Name: ESRI Metadata Profile