ASV_1000SHOT_SORT.SHP: Point Shapefile of 1000 Interval Seismic Shotpoint Navigation for Autonomous Surface Vessel IRIS Chirp Seismic Data in Apalachicola Bay Collected on U.S. Geological Survey Cruise 06001 (Geographic, WGS84)

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Frequently-anticipated questions:

What does this data set describe?

Title:
ASV_1000SHOT_SORT.SHP: Point Shapefile of 1000 Interval Seismic Shotpoint Navigation for Autonomous Surface Vessel IRIS Chirp Seismic Data in Apalachicola Bay Collected on U.S. Geological Survey Cruise 06001 (Geographic, WGS84)
Abstract:
Apalachicola Bay and St. George Sound contain the largest oyster fishery in Florida, and the growth and distribution of the numerous oyster reefs here are the combined product of modern estuarine conditions and the late Holocene evolution of the bay. A suite of geophysical data and cores were collected during a cooperative study by the U.S. Geological Survey, the National Oceanic and Atmospheric Administration Coastal Services Center, and the Apalachicola National Estuarine Research Reserve to refine the geology of the bay floor as well as the bay's Holocene stratigraphy. Sidescan-sonar imagery, bathymetry, high-resolution seismic profiles, and cores show that oyster reefs occupy the crests of sandy shoals that range from 1 to 7 kilometers in length, while most of the remainder of the bay floor is covered by mud. The sandy shoals are the surficial expression of broader sand deposits associated with deltas that advanced southward into the bay between 6,400 and 4,400 years before present. The seismic and core data indicate that the extent of oyster reefs was greatest between 2,400 and 1,200 years before present and has decreased since then due to the continued input of mud to the bay by the Apalachicola River. The association of oyster reefs with the middle to late Holocene sandy delta deposits indicates that the present distribution of oyster beds is controlled in part by the geologic evolution of the estuary. For more information on the surveys involved in this project, see <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2005-001-FA> and <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2006-001-FA>.
  1. How should this data set be cited?

    Twichell, David C. , and Cross, VeeAnn A. , 2012, ASV_1000SHOT_SORT.SHP: Point Shapefile of 1000 Interval Seismic Shotpoint Navigation for Autonomous Surface Vessel IRIS Chirp Seismic Data in Apalachicola Bay Collected on U.S. Geological Survey Cruise 06001 (Geographic, WGS84): Open-File Report 2012-1003, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Cross, V.A., Twichell, D.C., Foster, D.S., and O'Brien, T.F., 2012, Apalachicola Bay Interpreted Seismic Horizons and Updated IRIS Chirp Seismic-Reflection Data: Open-File Report 2012-1003, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -85.062710
    East_Bounding_Coordinate: -84.809553
    North_Bounding_Coordinate: 29.746692
    South_Bounding_Coordinate: 29.618457

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 03-Jun-2006
    Ending_Date: 27-Jun-2006
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • Entity point (2449)

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.

  7. How does the data set describe geographic features?

    asv_1000shot_sort
    ESRI point shapefile (Source: ESRI)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    lmarkname
    An abbreviated text field which provides a unique line name for each line of data acquisition associated with each point of data collection. The shorter name is easier to work with in the seismic interpretation software.

    Character set.

    shot
    Seismic shot number corresponding to the navigation fix. These values represent the start and end of each seismic line, and every 1000 shot along a line. (Source: Data processor.)

    Range of values
    Minimum:1
    Maximum:39499
    Units:seismic shot

    longitude
    Longitude coordinate of the point location in decimal degrees, WGS84. These values were calculated by XTools v. 5.2. (Source: Data processor.)

    Range of values
    Minimum:-85.06271
    Maximum:-84.809553
    Units:decimal degrees

    latitude
    Latitude coordinate of the point location in decimal degrees, WGS84. These values were calculated by XTools v. 5.2. (Source: Data processor.)

    Range of values
    Minimum:29.618457
    Maximum:29.746692
    Units:decimal degrees

    easting
    Easting coordinate of the point based on UTM, Zone 16, WGS84 calculated by XTools v 5.2. (Source: Data processor.)

    Range of values
    Minimum:687471.298707
    Maximum:711847.647456
    Units:meters

    northing
    Northing coordinate of the point based on UTM, Zone 16, WGS84 calculated by XTools v 5.2. (Source: Data processor.)

    Range of values
    Minimum:3278111.42877
    Maximum:3292656.76413
    Units:meters

    year
    Calendar year the data were collected. (Source: Data processor.)

    ValueDefinition
    2006Year in which the data were collected.

    jday
    This number represents the Julian day of data collection based on UTC time. Julian day is the integer number representing the interval of time in days since January 1 of the year. (Source: Data processor.)

    Range of values
    Minimum:154
    Maximum:178
    Units:day

    asv_name
    Text field with the original filename prepended by "asv06" to indicate the IRIS as the source of data collection. (Source: Data processor.)

    Character set.

    file_name
    The original file name of the acquired seismic line, which also corresponds to the prefix of the JPEG image filename associated with the seismic line. (Source: Data processor.)

    Character set.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov

Why was the data set created?

This shapefile contains the start and end shots, as well as every 1000th shot of the IRIS chirp data. These shot points aid the relation of the seismic-reflection profiles to other GIS data available in the same area.

How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    Source_Contribution:
    The data were collected using the USGS WHCMSC Autonomous Surface Vessel (ASV) IRIS. This system is designed to operate in shallow water (1-5 meters). IRIS is a catamaran platform 3 meters in length, 1.2 meters in width, and approximately 118 kilograms. The vehicle is operated remotely through a wireless modem network enabling real-time monitoring of data acquisition. The system is navigated using a ZXW RTK augmented GPS system enclosed on a platform in the middle of the catamaran. An enclosed onboard micro-processor-based motor controller provides signals for speed and steering to hull-mounted brushless direct-current thrusters. A center-mounted keel encloses the chirp dual-frequency (100/400 kHz model 4200 EdgeTech) sidescan-sonar transducers and EdgeTech 424 chirp seismic-reflection hydrophones. Mounted in the port hull are the EdgeTech 424 chirp seismic-reflection transducer and a single-beam 235 kHz echosounder. A Sony IP based wireless video camera is installed on the mast of IRIS for the purpose of obstacle avoidance. An onboard Fluxgate magnetometer provides heading, heave, pitch, and roll. IRIS is powered by 2-4 24-volt NiMH batteries located in each hull and has an approximate run-time of five hours at 4 knots.

  2. How were the data generated, processed, and modified?

    Date: 2008 (process 1 of 8)
    Seismic shot points at a regular interval can be extracted from a calibrated polyline-m seismic trackline. To do this, within ArcMap 9.2 hatches were created from the layer properties of the calibrated polyline. For Hatch Class, set the hatch interval to 1. Select the "Hatch Placement" button and check to start hatching at a value other than the lowest measure - start hatching at 0. Hatch definition (1000) - place hatches every 1000 hatch intervals using a marker symbol. Add Hatch Definition - add end hatch definition. For HatchDef(End) set the hatch to a marker, tolerance 0, and lateral offset 0. For this work there seemed to be a problem with a couple of the lines in terms of generating the start hatch. I was unable to figure out the problem and will just have to copy over shot one from the point shapefile at the end of the procedure. The affected lines are: asv06_JD175000, asv06_JD176001, asv06_JD176003 and asv06_day165005. This process step as well as all subsequent process steps was performed by the same person - VeeAnn A. Cross.

    Person who carried out this activity:

    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov

    Data sources used in this process:
    • asv_lines_Calibrated.shp

    Data sources produced in this process:

    • graphic hatches

    Date: 2008 (process 2 of 8)
    With all the hatches drawn, use the "convert hatches to graphics tool". This tool does not appear automatically and must manually be added to the toolbar. To do this, from the ArcMap (v. 9.2) menu Tools - Customize. Select the Commands tab. In the categories listing, scroll down to Linear Referencing and select "Convert Hatches to Graphics..." and drag and drop to an existing toolbar in ArcMap. Then click on this button. In the pop-up menu, select All feature in the layer, select the appropriate Hatch Class. Leave the default to draw only the converted graphics.

    Date: 2008 (process 3 of 8)
    Then within ArcMap 9.2 use XTools Pro version 5.2 to convert the graphics to a shapefile. Feature conversions - Graphics to Shapes. Output: asv_1000shot_gra and automatically add feature class to current map. Do not add ID field and do not add TEXT field.

    Date: 2008 (process 4 of 8)
    Within ArcMap 9.2 - ArcToolbox - Linear Referencing - Locate Features Along Routes. Input features: asv_1000shot_gra; input route features: asv_lines_Calibrated; route identifier: lmarkname; search radius: 1 meter (a slight search radius is needed because of rounding errors, some points would be lost); output event table: asv_1000shot_gra_LocateFeatu.dbf; output route identifier: lmarkname; measure field: shot. Left rest of options at default.

    Date: 2008 (process 5 of 8)
    Within ArcMap 9.2 - ArcToolbox - Linear Referencing - Make Route Event Layer. Input route: asv_lines_Calibrated; route identifier: lmarkname; input event table: asv_1000shot_gra_LocateFeatu.dbf. For the event table properties, route identifier: lmarkname; event type: point; measure field: shot; left rest of options at default values. Then right mouse click on the event theme - data - export data. Export all the features to asv_1000shot.shp. At this point, copy the four missing shot #1's from allasv_nodupes_sort.shp into this shapefile from within editor.

    Date: 2009 (process 6 of 8)
    Within ArcMap 9.2 use VACExtras v 2.1 - VAC Extras - Feat Conv - Table Sort with the primary sort field lmarkname in ascending order and the secondary sort field is shot in ascending order. Output the result to asv_1000shot_sort.shp.

    Date: 2009 (process 7 of 8)
    Use XTools Pro v. 5.2 - XTools Pro - Table Operations - Add X, Y, Z coordinates. Add X coordinate with field name longitude and y coordinate with field name latitude. Then repeat the process specifying the output projection as UTM, Zone 16, WGS84 and add the X coordinate with field name easting and the Y coordinate with field name northing.

    Date: 2009 (process 8 of 8)
    Additionally, I want to carry over some of the other information from the original point shapefile such as year, jday, and filename. Add the field "year" and use field calculator to set all the record values to 2006. Add the additional fields "jday" and "filename". To populate these fields, join this point shapefile to the asv_lines shapefile based on the lmarkname attribute. Select to join attributes from a table, field to base the join on in both tables - lmarkname. With the tables joined, can use field calculator to copy over the appropriate values. Then deleted the unnecessary fields generated during the locate features procedure - distance and ID.

  3. What similar or related data should the user be aware of?

    Twichell, D.C., Andrews, B.D., Edmiston, H.L., and Stevenson, W.R., 2007, Geophysical mapping of oyster habitats in a shallow estuary; Apalachicola Bay, Florida: Open-File Report 2006-1381, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    Twichell, D.C., Pendleton, E.A., Poore, R.Z., Osterman, L.E., and Kelso, K.W., 2009, Vibracore, radiocarbon, microfossil, and grain-size data from Apalachicola Bay, Florida: Open-File Report 2009-1031, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Bergeron, E., Worley, C.R., and O'Brien, T.F., 2007, Progress in the development of shallow-water mapping systems: using an autonomous surface vehicle for shallow-water geophysical studies: Sea Technology v. 48, no. 6, p. 10-15, Compass Publications, Inc., Arlington, VA.

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

    IRIS was navigated with a Real-Time Kinematic (RTK) GPS, with the GPS antenna mounted directly over the seismic transducer. This system can provide positions to within 0.1 meters. However, due to some errors with the acquisition software, this accuracy is reduced. The accuracy is approximately 2 m given the constraints of the acquisition system.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    No data were acquired on the following dates: 6/8/2006, 6/10/2006 6/12/2006, 6/13/2006, 6/15/2006, 6/16/2006, 6/17/2006, 6/18/2006, 6/19/2006, 6/20/2006. These dates correspond to Julian days 159, 161, 163, 164, 166, 167, 168, 169, 170, and 171 respectively. In addition, lines for which no valid seismic data were available, or extremely short lines, were deleted. Some lines acquired seismic data, but little or no navigation. These lines are also excluded. One line was re-run, so the original problematic line was excluded. The list of collected seismic lines excluded from this and subsequent datasets is as follows: Julian day 155 - apalachicola000 (rerun), apalachicola020 (too short), apalachicola027 (insufficient navigation). Julian day 160 - day160001 (insufficient navigation). Julian day 165 - day165001 (too short). Julian day 172 - JD172010 (too short), JD172014 (too short), JD172025 (too short). Julian day 173 - JD173009 (too short). Julian day 174 - JD174010 (too short).

  5. How consistent are the relationships among the observations, including topology?

    All of the data were handled in the same manner. All processed lines have a start shot, end shot, and every 1000th shot in between. Inconsistencies exist in the file naming convention for individual seismic data collection lines. Because the filenames reflect the original data file names acquired in the field, they were left alone.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None.
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the originators of this dataset.

  1. Who distributes the data set? (Distributor 1 of 1)

    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    Woods Hole Coastal and Marine Science Center
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov

  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    Neither the U.S. government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    This WinZip file contains data available in ESRI point shapefile format. The user must have software capable of uncompressing the WinZip file and reading/displaying the shapefile.

Who wrote the metadata?

Dates:
Last modified: 12-Apr-2012
Metadata author:
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
Woods Hole Coastal and Marine Science Center
Woods Hole, MA 02543-1598

(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.9.6 on Wed Apr 18 17:10:38 2012