2010 Bathymetric Survey and DEM of Corte Madera Bay, California

Metadata also available as

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator:
U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), Santa Cruz, CA.
Publication_Date: 2011
Title: 2010 Bathymetric Survey and DEM of Corte Madera Bay, California
Geospatial_Data_Presentation_Form: raster digital data
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: OF2011-1217
Online_Linkage: <https://pubs.usgs.gov/of/2011/1217>
Description:
Abstract:
A 10-m resolution seamless bathy/topo DEM of Corte Madera Bay generated by merging USGS bathymetry with NOAA's bare earth aerial topographic lidar data processed to bare earth, both collected in early 2010.
Reference Frame = NAD83(CORS96) Vertical Datum = NAVD88, all units in meters.
Purpose:
Bathy/topo DEM of Corte Madera Bay developed for use in wave-attenuation studies and sea level rise analyses.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20100126
Ending_Date: 20100330
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -122.504712
East_Bounding_Coordinate: -122.458596
North_Bounding_Coordinate: 37.943068
South_Bounding_Coordinate: 37.905329
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: Elevation
Theme_Keyword: Bathymetry
Theme_Keyword: LiDAR
Theme_Keyword: Bare Earth
Theme_Keyword: Terrain
Place:
Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: USA
Place_Keyword: State of California
Place_Keyword: San Francisco Bay
Place_Keyword: Marin County
Place_Keyword: Corte Madera
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. 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.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USGS Pacific Coastal and Marine Science Center
Contact_Person: David P Finlayson
Contact_Position: Operational Geologist
Contact_Address:
Address_Type: physical address
Address: 400 Natural Bridges Drive
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060
Country: USA
Contact_Voice_Telephone: (831) 427-4757
Contact_Facsimile_Telephone: (831) 427-4748
Contact_Electronic_Mail_Address: dfinlayson@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name:
<http://walrus.wr.usgs.gov/infobank/s/s310sf/html/s-3-10-sf.index.png>
Browse_Graphic_File_Description: Image showing S-3-10-SF survey tracklines.
Browse_Graphic_File_Type: PNG
Browse_Graphic:
Browse_Graphic_File_Name:
<http://walrus.wr.usgs.gov/infobank/s/s910sf/html/s-9-10-sf.index.png>
Browse_Graphic_File_Description: Image showing S-9-10-SF survey tracklines.
Browse_Graphic_File_Type: PNG
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
This bathymetric data has not been independently verified for accuracy.
Logical_Consistency_Report:
All bathymetric values are derived from the same instruments and processing workflow.
Completeness_Report:
Two separate bathymetric surveys of Corte Madera Bay were conducted: the first (USGS Field Activity ID: S-3-10-SF) from January 26 - 29, 2010 and the second (USGS Field Activity ID: S-9-10-SF) on March 29 and 30, 2010. The combined bathymetric surveys consist of 215 survey lines covering an area of approximately 6.5 square km extending north to the dredged ferry channel leading to Corte Madera Creek and to the south, just beyond Paradise Cay Yacht Harbor.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Uncertainty in the horizontal position of each sounding is a function of the total uncertainty propagated through each of the following component instruments: 1) base station GPS, 2) vessel GPS, 3) intertial motion unit (IMU), 4) water sound velocity model, and 5) beam spreading in the water column. Assuming no systematic errors in the measurement instruments themselves, beam spreading is the dominate source of positional uncertainty. The 1-degree sonar beam of the SWATHplus-M results in horizontal uncertainty ranging from 0.10 m at 10 m slant range, to about 0.45 m at 50 m slant range.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
After filtering the data to remove obvious outliers, the standard deviation of the remaining sounding elevations was calculated for each 1 m x 1 m cell (each containing over 400 soundings on average) in CARIS. The mean of the standard deviation for all cells in the Corte Madera survey is 0.06 m and 98% of the cells in the data set have a standard deviation of less than 0.15 m.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey, Coastal and Marine Geology Program
Title: USGS CMG Field Activity S-3-10-SF
Geospatial_Data_Presentation_Form: raster digital data
Online_Linkage:
<http://walrus.wr.usgs.gov/infobank/s/s310sf/html/s-3-10-sf.meta.html>
Type_of_Source_Media: online
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20100126
Ending_Date: 20100129
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: S-3-10-SF
Source_Contribution:
This 2010 field activity collected bathymetric data in San Francisco Bay.
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey, Coastal and Marine Geology Program
Title: USGS CMG Field Activity S-9-10-SF
Geospatial_Data_Presentation_Form: raster digital data
Online_Linkage:
<http://walrus.wr.usgs.gov/infobank/s/s910sf/html/s-9-10-sf.meta.html>
Type_of_Source_Media: online
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20100329
Ending_Date: 20100330
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: S-9-10-SF
Source_Contribution:
This 2010 field activity collected bathymetric data in San Francisco Bay.
Process_Step:
Process_Description:
Sonar Data Collection
The bathymetric surveys were conducted using a 234.5 kHz SEA (Systems Engineering & Assessment Ltd) SWATHplus-M phase-differencing sidescan sonar. The sonar was pole-mounted on the 34-foot USGS mapping vessel R/V Parke Snavely, and affixed to a hull brace. Real-time kinematic (RTK) GPS position data were passed through a CodaOctopus F180 intertial measurement unit (IMU) to the sonar hardware and data collection software. Sonar heads, GPS antennae, and the IMU were surveyed in place to a common reference frame with a Geodimeter 640 Total Station. The R/V Snavely was outfitted with three networked workstations and a navigation computer for use by the captain and survey crew for data collection and initial processing.
Process_Date: 2010
Process_Step:
Process_Description:
Geodetic Control
Geodetic control for the survey was established using a shore based Global Positioning System (GPS) base station broadcasting Real Time Kinematic (RTK) corrections to the survey vessel via UHF radio link. The base station was located in the hills along Taylor Drive. The base station was programmed using the WGS84 (G1150) reference frame with an Epoch of 2010.1532.
The base station was programmed using the following coordinates: (see also CM01-base-setup.JPG) Reference Frame: WGS84 (G1150) Epoch: 2010.0630 Latitude: N 37° 54 51.37721 Longitude: W 122° 29 13.21809 Ellipsoid Height: 88.829m
The average value for the derived OPUS solutions for CM01 are: Reference Frame: ITRF00 [same as WGS84 (G1150)] Epoch: 2010.1532 Latitude: N 37° 54 51.37819 Longitude: W 122° 29 13.21786 Ellipsoid Height: 88.780m
The differences to be added to the RTK broadcast locations are: Latitude: +0.00098 Longitude: -0.00023 Ellipsoid Height: -0.049m
Using UTM coordinates as a comparison: The base station was programmed using the following coordinates: Reference Frame: NAD83, UTM zone 10 Epoch: 2002.0000 Northing: 4196426.796m Easting: 545093.600m Ellipsoid Height: 89.359m Orthometric Height: 121.700m (based Geoid09)
The average value for the derived OPUS solutions for CM01 are: Reference Frame: NAD83, UTM zone 10 Epoch: 2002.0000 Northing: 4196426.825m Easting: 545093.607m Ellipsoid Height: 89.310m Orthometric Height: 121.651m (based Geoid09)
The differences to be added to the RTK broadcast locations are: Northing: +0.029m Easting: +0.007m Ellipsoid Height: -0.049m Orthometric Height: -0.049m
Process_Date: 2010
Process_Step:
Process_Description:
Vessel Position and Attitude
The R/V Snavely was equipped with a CodaOctopus F180 attitude and positioning 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 2010.1532 3-dimensional reference frame was used for all data acquisition.
Process_Date: 2010
Process_Step:
Process_Description:
Sound Velocity Measurements
Sound velocity measurements were collected continuously with an Applied Micro Systems Micro SV deployed on the transducer frame for real-time sound velocity adjustments at the transducer-water interface. The Micro SV is accurate to +/- 0.03 m/s. In addition, sound velocity profiles (SVP) were collected with an Applied Micro Systems, SvPlus 3472. This instrument provides time-of-flight sound-velocity measurements by using invar rods with a sound-velocity accuracy of ±0.06 m/s, pressure measured by a semiconductor bridge strain gauge to an accuracy of 0.15 percent (Full Scale) and temperature measured by thermistor to an accuracy of 0.05 degrees Celsius (Applied Microsystems Ltd., 2005).
Process_Date: 2010
Process_Step:
Process_Description:
Sonar Sounding Processing
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). The returned samples are projected to the seafloor using a ray-tracing algorithm working with the previously 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 seafloor returns from other uninteresting targets in the water column. Finally, the processed data is stored line-by-line in both raw (.sxr) and processed (.sxp) trackline files. Processed (.sxp) files were further processed with sxpegn (build 151) by Amy Foxgrover (USGS) to remove erroneous data from the files and make valid gain-normalized amplitude data for processing backscatter data.
Process_Date: 2010
Process_Step:
Process_Description:
Bathy Digital Elevation Model Production The 1-m resolution BASE surface was created in CARIS using a swath angle weighting scheme where higher weight is given to soundings from the inner part of a swath than to outer beams from adjacent track lines. To convert the data from the WGS84 (G1150) ellipsoid to NAD83 (CORS96), the 1 meter-grid resolution data was exported from CARIS to an X,Y,Z point file. Next, a 14-point Helmert transformation was applied with time-dependent transformation parameters figured for January 23, 2010, according to methods outlined in Soler and Snay (2004). The NAD83 (CORS96) ellipsoid elevations were then converted to orthometric heights based on NAVD88 and the National Geodetic Survey (NGS) Geoid09 Model (NGS, 2009) in VDatum v 2.3.0 (<http://vdatum.noaa.gov/>).
The data was imported into Fledermaus for interpolation using a weighted moving average gridding algorithm with a weight diameter of 100 m. This grid has been interpolated to fill gaps in the data between track lines.
Process_Date: 20110320
Process_Step:
Process_Description:
Topo/Bathy Digital Elevation Model Production The interpolated 1-m resolution bathymetric grid was merged with NOAA's topographic lidar data using the blend algorithm in the Mosaic to New Raster tool in Arc Toolbox to create a seamless DEM. The DEM was then resampled to 10-m resolution using a bilinear interpolation.
NOAA's Coastal Services Center (CSC) contracted the acquisition of aerial topographic lidar by Fugro EarthData, Inc. in the spring of 2010 which happened to cover our study area. NOAAs Northern San Francisco Bay aerial lidar was collected from February 25th to April 16th, 2010 using a Piper Navajo twin engine aircraft equipped with a Lecia ALS60 lidar system. Acquisition was designed to support a nominal point spacing of 1 meter and collected at low tide to optimize coverage of the intertidal flats. Lidar data was processed by Fugro to achieve a bare earth ground surface and provided as 1-m resolution hydro-flattened grids. The stated horizontal accuracy of the lidar is 1 meter RMSE or better. When Fugro compared the lidar to survey grade GPS points in generally flat, non-vegetated areas the vertical accuracy of 95% of the positions had errors less than or equal to 18 cm (equivalent to a 9 cm RMSE if evenly distributed). The lidar is projected in UTM coordinate space, zone 10. The vertical datum is NAVD88 and the horizontal datum NAD83 (NSRS2007). Within our study area NAD83 (NSR2007) very closely approximates the horizontal datum of the bathymetric data, NAD83 (CORS96), and is within the accuracy of the data. For our purposes the two versions of NAD83 are considered equivalent.
For additional information on NOAAs Northern San Franscisco Bay lidar data set or to download the data directly visit NOAAs CSC website <http://www.csc.noaa.gov/ldart>.
Process_Date: 20110320
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Lidar data provided by: Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC)
Contact_Position: CEM Project Scientist
Contact_Address:
Address_Type: mailing and physical address
Address: 2234 South Hobson Ave.
City: Charleston
State_or_Province: South Carolina
Postal_Code: 29405
Country: USA
Contact_Voice_Telephone: 843.740.1200
Contact_Electronic_Mail_Address: tcm@csc.noaa.gov
Hours_of_Service: 9:00am - 5:00pm
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: raster
Raster_Object_Information:
Raster_Object_Type: grid cell
Row_Count: 428
Column_Count: 607
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 10
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -123
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000
False_Northing: 0.0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 10.0
Ordinate_Resolution: 10.0
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983 (CORS96)
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137
Denominator_of_Flattening_Ratio: 298.257
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum 1988
Altitude_Resolution: 0.01
Altitude_Distance_Units: meters
Altitude_Encoding_Method: Attribute values
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: Altitude
Entity_Type_Definition:
Orthometric Altitude (elevation) relative to NAVD88 in meters. Values are positive up.
Entity_Type_Definition_Source: NA
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
U.S. Geological Survey, Pacific Coastal and Marine Science Center (PCMSC)
Contact_Person: David P Finlayson
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: 831-427-4757
Contact_Facsimile_Telephone: 831-427-4748
Contact_Electronic_Mail_Address: dfinlayson@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.
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: ESRI ASCII Grid
Format_Version_Number: 1.0
Format_Information_Content:
The ASCII file consists of header information containing a set of keywords, followed by cell values in row-major order. The file format is:
<NCOLS xxx> <NROWS xxx> <XLLCENTER xxx | XLLCORNER xxx> <YLLCENTER xxx | YLLCORNER xxx> <CELLSIZE xxx> {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. 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 are be delimited by spaces. No carriage returns are necessary at the end of each row in the grid (although they are included in this case). The number of columns in the header is used to determine when a new row begins. The number of cell values is equal to the number of rows times the number of columns.
Transfer_Size: 1 MB (compressed)
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <https://pubs.usgs.gov/of/2011/1217/>
Fees: No cost
Metadata_Reference_Information:
Metadata_Date: 20110429
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Amy Foxgrover
Contact_Address:
Address_Type: mailing address
Address: 400 Natural Bridges Drive
City: Santa Cruz
State_or_Province: California
Postal_Code: 95060
Country: USA
Contact_Voice_Telephone: 831-427-4785
Contact_Electronic_Mail_Address: afoxgrover@usgs.gov
Hours_of_Service: 9 am to 5 pm Pacific Time (GMT -7)
Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Generated by mp version 2.9.12 on Thu Oct 13 21:31:06 2011