Attribute_Accuracy_Report:
The accuracy of the data is determined during data collection. This dataset is derived from multiple research cruises using identical equipment, set-ups, and staff; therefore, it is internally consistent. Methods are employed to maintain data collection consistency aboard the platform. During mobilization, each piece of equipment is isolated to obtain internal and external offset measurements with respect to the survey platform. All the critical measurements are recorded manually and digitally entered into their respective programs. Offsets between the single-beam transducers and the Ashtech antenna reference point (ARP) were measured and accounted for in post-processing. Bar checks were performed as calibration efforts and accounted for any drift in the Marimatech Echosounder. Differential Geographic Positioning System (DGPS) coordinates were obtained using post-processing software packages developed by the National Oceanic and Atmospheric Administration (NOAA)/National Geodetic Survey (NGS) Online Positioning User Service (OPUS), National Aeronautics and Space Administration (NASA)/Jet Propulsion Laboratory (JPL) Online Positioning User Service (GIPSY), and Scripps Orbit and Permanent Array Center Online Positioning User Service (SCOUT). Boat trajectories were computed with PNAV v2.0 software by ASHTECH, Inc. These bathymetric data have not been independently verified for accuracy.
This dataset was acquired on a single research cruise in 2009, which was equipped with identical hardware and software systems.
These are complete post-processed x,y,z bathymetric data points collected in the Ten Thousand Island area in 2009, using an acoustic single-beam system.
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The GPS antenna and receiver acquisition configuration used at the reference station was duplicated on the survey vessel (rover). The base receiver and the rover receiver record their positions concurrently at 1Hz recording intervals throughout the survey. All processed measurements are referenced to the base station coordinates.
GPS base or differential reference stations were operated within approximately 15 to 20 km of the survey area. One new temporary ground-control points or benchmarks (surveyed to within 1 cm to 2 cm accuracy) were established throughout the study area for use as reference receiver sites using standard benchmarks procedures. The new benchmark was surveyed using Ashtech Z-12, 12 channel dual-frequency GPS receivers. Full-phase carrier data were recorded on each occupied benchmark in Ashtech proprietary BIN format with daily occupations ranging from 6 to 12 hours. BIN files were then converted to RINEX-2 format for position processing.
All static base station GPS sessions were submitted for processing to the online OPUS, GIPSY, and SCOUT system software. The computed base location results were entered into a spreadsheet to compute one final positional coordinate and error analysis for that base location. The final positional coordinate (latitude, longitude, and ellipsoid height) is the weighted average of all GPS sessions. For each GPS session, the weighted average was calculated from the total session time in seconds; therefore, longer GPS occupation times held more value than shorter occupation times. Results were computed relative to ITRF00 coordinate system. The established geodetic reference frame for the project was WGS84. Therefore, final reference coordinates used to process the rover data were transformed from ITRF00 to WGS84 using National Oceanic and Atmospheric Administration/National Geodetic Survey(NOAA/NGS) HTDP software v2.1.
OPUS, GIPSY, and SCOUT results provide an error measurement for each daily solution. Applying these error measurements, the horizontal accuracy of the base station is estimated to be 0.04 (m) root mean squared (RMS).
The kinematic (rover) trajectories were processed using PNAV v2.0, by ASHTECH, Inc. A horizontal error measurement, RMS is computed for each epoch. The horizontal trajectory errors for varied between 0 and 0.08(m).
The combined horizontal error from base station coordinate solutions and rover trajectories range from 0 and 0.12 (m), with the average approximately 0.06 (m).
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 0.04
Horizontal_Positional_Accuracy_Explanation:
Static GPS data was processed using OPUS, GIPSY, and SCOUT software and kinematic GPS data was processed with PNAV v2.0 software by ASHTECH, Inc. and SANDS v1.2
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
The GPS antenna and receiver acquisition configuration used at the reference station was duplicated on the survey vessel (rover). The base receiver and the rover receiver record their positions concurrently at 1Hz recording intervals throughout the survey. All processed measurements are referenced to the base station coordinates.
GPS base or differential reference stations were operated within approximately 15 to 20 km of the survey area. One new temporary ground-control points or benchmarks (surveyed to within 1 cm to 2 cm accuracy) were established throughout the study area for use as reference receiver sites using standard benchmarks procedures. The new benchmarks were surveyed using Ashtech Z-12, 12 channel dual-frequency GPS receivers. Full-phase carrier data were recorded on each occupied benchmark in Ashtech proprietary BIN format with daily occupations ranging from 6 to 12 hours. BIN files were then converted to RINEX-2 format for position processing.
All static base station GPS sessions were submitted for processing to the online OPUS, GIPSY, and SCOUT system software. The computed base location results were entered into a spreadsheet to compute one final positional coordinate and error analysis for that base location. The final positional coordinate (latitude, longitude, and ellipsoid height) is the weighted average of all GPS sessions. For each GPS session, the weighted average was calculated from the total session time in seconds; therefore, longer GPS occupation times held more value than shorter occupation times. Results were computed relative to ITRF00 coordinate system. The established geodetic reference frame for the project was WGS84. Therefore, final reference coordinates used to process the rover data were transformed from ITRF00 to WGS84 using National Oceanic and Atmospheric Administration/National Geodetic Survey(NOAA/NGS) HTDP software v2.1.
OPUS, GIPSY, and SCOUT results provide an error measurement for each daily solution. Applying these error measurements, the vertical accuracy of the base station is estimated to be 0.04 (m) root mean squared (RMS).
The kinematic (rover) trajectories were processed using PNAV v2.0, by ASHTECH, Inc. A vertical error measurement, RMS is computed for each epoch. The vertical trajectory errors for varied between 0 and 0.08(m).
The combined vertical error from base station coordinate solutions and rover trajectories range from 0 and 0.14 (m), with the average approximately 0.08 (m).
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: 0.08
Vertical_Positional_Accuracy_Explanation:
Static GPS data was processed using OPUS, GIPSY, and SCOUT software and kinematic GPS data was processed with PNAV v2.0 software by ASHTECH, Inc. and SANDS v1.2
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: Unpublished material
Title: 2009 Ten Thousand Islands, Florida single-beam bathymetry
Type_of_Source_Media: digital tabular data
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2009
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: USGS Ten Thousand Islands bathymetry
Source_Contribution: Original processed bathymetric data.
Process_Step:
Process_Description:
Data Acquisition - The sea-floor of Ten Thousand Islands was mapped by using an outboard motor boat, equipped with a high-precision Global Positioning Systems (GPS) coupled with a high-precision depth sounder. To accomplish this task, the SANDS (System for Accurate Nearshore Depth Surveying) system was developed by Mark Hansen (SPCMSC) and Jeff List (WHSC) of the U.S. Geological Survey. SANDS consists of two components, hardware and processing software.
Survey tracklines were spaced 500-meters apart and orientated in a north/south orientation. Channels and inlets were surveyed in greater detail. Tracklines collected parallel to the bay shoreline (intersecting tracklines) functioned to serve as a cross-check and to assess the relative vertical accuracy of the survey. Crossing lines are critical because they serve as a check on the internal accuracy of the data. Soundings were collected along each trackline at 3 m spacing. In shallow areas, data were collected in a minimum of 0.3 m water depth except where there was potential damage to the bottom environment or the boat/motors.
Reference GPS reference stations were operated on an USGS benchmark, typically located within approximately 15 km of the farthest single-beam trackline. Reference and rover GPS receivers recorded the 12-channel full-carrier-phase positioning signals (L1/L2) from satellites via ASHTECH choke-ring antennas. The reference and rover receivers record their positions concurrently at 1-second(s) recording intervals throughout the survey.
Boat motion was recorded at 50-millisecond (ms) intervals using a TSS Dynamic Motion Sensor 05 (TSS DMS-05). Bathymetric soundings were recorded at 10-ms intervals using an Marimatech EC-100 survey grade echo-sounder. The single-beam data were acquired using the hydrographic software HYPACK version 5. All data strings from the instruments were streamed in real time and recorded through HYPACK software.
Process_Date: 2010
Source_Produced_Citation_Abbreviation:
Raw sensor data files in ASCII text format and GPS Carrier-phase data in binary format.
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: Mark Hansen
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical
Address: 600 4th Street South
City: St. Petersburg
State_or_Province: FL
Postal_Code: 33701
Country: USA
Contact_Voice_Telephone: (727) 502-8000
Contact_Electronic_Mail_Address: mhansen@usgs.gov
Process_Step:
Process_Description:
Differentially Corrected Navigation Processing- The coordinate values of the reference GPS base stations obtained from OPUS were provided in the ITRF00 coordinate system. All survey data for the project was referenced to WGS84. Consequently, reference station coordinates were transformed to WGS84 coordinates using the NOAA/NGS software HTDP v1.3. The respective reference (base) station coordinates utilized as reference positions were imported into PNAV v2.0 software by ASHTECH, Inc. Differentially corrected rover trajectories were computed by merging the master and rover the GPS data. During processing, steps were taken to ensure that the trajectories between the base and rover were clean, resulting in fixed positions. By analysing the graphs, trajectory maps, and processing logs that GrafNav produces for each GPS session, GPS data from satellites flagged by the program as having poor health or satellite time segments that had cycle slips could be excluded, or the satellite elevation mask angle could be adjusted to improve the position solutions. The final differentially corrected precise DGPS positions were computed for each rover GPS session and exported in ASCII text format.
Process_Date: 2010
Source_Produced_Citation_Abbreviation: Boat trajectory data files in ASCII text format.
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Mark Hansen
Contact_Organization: U.S. Geological Survey
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: 600 Fourth St. South
City: St. Petersburg
State_or_Province: FL
Postal_Code: 33701
Contact_Voice_Telephone: 727-502-8000
Contact_Facsimile_Telephone: 727-502-8032
Contact_Electronic_Mail_Address: mhansen@usgs.gov
Process_Step:
Process_Description:
Single-beam Bathymetry Processing- All data were processed using SANDS version 1.2. The primary purpose of SANDS is to time synchronize processed trajectories, soundings, and heave/pitch/roll, then merges all data strings. SANDS applies latency errors, applies geometric corrections for antenna staff pitch and roll, applies geometric corrections for antenna transducer pitch and roll (beam correction), time synchronizes the GPS trajectory and HYPACK files for each GPS epoch, and converts WGS84 latitude/longitude coordinates to North American Datum of 1983 NAD83/GRS80 UTM coordinates (m), and applies a geoid separation based upon NOAA/NGS the Geoid99 model. Latitude/longitude conversion to UTM coordinates was accomplished using NOAA/NGS UTM v2.0 software. Intermediate output files are comma delimited text files containing: time of day (seconds of day), UTM X coordinate (m), UTM Y coordinate (m), ellipsoid height, orthometric height, smoothed raw depths, PNAV RMS value, and HYPACK line number. A header line indicates the attributes entry for each column.
Source_Used_Citation_Abbreviation:
Completely processed final XYZ files representing sea-floor elevations.
Process_Date: 2010
Source_Produced_Citation_Abbreviation: Final processed bathymetry data files in ASCII text format.
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Mark Hansen
Contact_Organization:
U.S. Geological Survey (USGS) - St. Petersburg Coastal and Marine Science Center
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical address
Address: 600 4th Street South
City: St. Petersburg
State_or_Province: FL
Postal_Code: 33701
Country: USA
Contact_Voice_Telephone: 727-502-8000
Contact_Facsimile_Telephone: 727-502-8032
Contact_Electronic_Mail_Address: mhansen@usgs.gov
Process_Step:
Process_Description:
The final processed bathymetry files were reformatted for publication. UTM coordinate were converted to latitude/longitude using NOAA/NGS UTMS v2.0 software. Shapefiles were created from X,Y,Z text files using in-house developed software.
Process_Date: 2015
Source_Produced_Citation_Abbreviation:
DS1031-10KIslands_WGS84_NAVD88-G03_SB.xyz.txt,DS1031-10KIslands_WGS84_NAVD88-G03_SB.xyz.shp
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: Mark Hansen
Contact_Position: Oceanographer
Contact_Address:
Address_Type: mailing and physical
Address: 600 4th Street South
City: St. Petersburg
State_or_Province: FL
Postal_Code: 33701
Country: USA
Contact_Voice_Telephone: (727) 502-8000
Contact_Facsimile_Telephone: (727) 502-8032
Contact_Electronic_Mail_Address: mhansen@usgs.gov
Process_Step:
Process_Description:
Added keywords section with USGS persistent identifier as theme keyword.
Process_Date: 20201013
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
