Peak marine sparker amplitude data from calibrated source and receive hydrophones collected in April 2021 offshore Santa Cruz, California (USGS field activity 2021-619-FA), and pressure vs. offset plots

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• What does this data set describe?
  1. How might this data set be cited?
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  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
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What does this data set describe?

1. How might this data set be cited?
   Balster-Gee, Alicia F., Baldwin, Wayne E., and Hart, Patrick E., 20220920, Peak marine sparker amplitude data from calibrated source and receive hydrophones collected in April 2021 offshore Santa Cruz, California (USGS field activity 2021-619-FA), and pressure vs. offset plots: data release DOI:10.5066/P9EHITBI, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9EHITBI

   This is part of the following larger work.
   Balster-Gee, Alicia F., Baldwin, Wayne E., and Hart, Patrick E., 2022, Calibrated marine sparker source amplitude decay versus offset offshore Santa Cruz, California: data release DOI:10.5066/P9EHITBI, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P9EHITBI

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -122.47431993
   East_Bounding_Coordinate: -121.81507587
   North_Bounding_Coordinate: 37.09648707
   South_Bounding_Coordinate: 36.72920243
   

3. What does it look like?

   L200_SIGminisparkerAmplitudeOffestPlots_2021-619-FA.png (PNG)

   Summary peak amplitude plots for the SIG minisparker operated at 600J at the 200-meter depth site. On the left, the top scatter plot shows the pulses recorded at the hydrophone deployed near the sparker source on the R/V Parke Snavely (source vessel); the bottom scatter plot shows the peak amplitude signal recorded at the hydrophone deployed at the R/V San Lorenzo (receiver vessel). On the right are the 51-trace mean filtered version of the same data.

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

   Beginning_Date: 19-Apr-2021

   Ending_Date: 28-Apr-2021

   Currentness_Reference:

   ground condition at time data were collected

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

   Geospatial_Data_Presentation_Form: comma-delimited text
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (46332)
   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 WGS 1984.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257224.
      

      Vertical_Coordinate_System_Definition:

      Depth_System_Definition:

      Depth_Datum_Name: Local surface
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
      

7. How does the data set describe geographic features?

   2021-619-FA_RVPS_SEGYpeakamplitude_csv.zip

   zip file containing 30 csv summary tables for each SEG-Y recorded with the TC4304 hydrophone aboard the R/V Parke Snavely source vessel. The first line of the csv files is a header line. (Source: Producer defined)

   filename

   Name of navigation line (Source: Assigned unique line identifier name)

   Value	Definition
   PS-L25_S_a_f2	Pass ‘a’ part 2 with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site
   PS-L25_S_a_f3	Pass ‘a’ part 3 with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site
   PS-L25_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site
   PS-L25_S_c	Pass ‘c’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site
   PS-L25A_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the second 25-meter depth site ‘25A’
   PS-L25A_S_a2	Pass ‘a2’ (part two of pass a) with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site ‘25A’
   PS-L25A_S_a3	Pass ‘a3’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site ‘25A’
   PS-L25A_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site ‘25A’
   PS-L50_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site
   PS-L50_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site
   PS-L50A_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site ‘50A'
   PS-L50A_S_a2	Pass ‘a2’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site ‘50A’
   PS-L50A_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site ‘50A’
   PS-L100_S_a_f1	Pass ‘a’ (part 1) with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   PS-L100_S_a_f2	Pass ‘a’ (part 2) with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   PS-L100_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   PS-L100_S_c_f1	Pass ‘c’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   PS-L100_S_c_f2	Pass ‘c2’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   PS-L100_S_c2	Pass ‘c2’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   PS-L200_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 200-meter depth site
   PS-L200_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 200-meter depth site
   PS-L200_S_c	Pass ‘c’ with the SIG ELP790 minisparker source (power 700 joules) at the 200-meter depth site
   PS-L200_D10_a	Pass ‘a’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site
   PS-L200_D10_b	Pass ‘b’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site
   PS-L200_D10_c	Pass ‘c’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site
   PS-L200_D10_d	Pass ‘d’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site Enumerated_Domain_Value_Definition_Source: Producer defined
   PS-L600_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 600-meter depth site
   PS-L600_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 600-meter depth site
   PS-L600_D24_a	Pass ‘a’ with the Delta sparker source (power 2.4 kilojoules) at the 600-meter depth site
   PS-L600_D24_b	Pass ‘b’ with the Delta sparker source (power 2.4 kilojoules) at the 600-meter depth site

   hpid

   Hydrophone Identifier (Source: producer defined) model number TC4034 (Reson)

   lbsrc_lon

   longitude of the sparker source layback position from the stern of the source vessel (RVPS) (Source: producer defined)

   Range of values
   Minimum:	-122.360614
   Maximum:	-121.897050
   Units:	decimal degrees
   Resolution:	0.000001

   lbsrc_lat

   latitude of the sparker source layback position from the stern of the source vessel (RVPS) (Source: producer defined)

   Range of values
   Minimum:	36.763513
   Maximum:	36.992312
   Units:	decimal degrees
   Resolution:	0.000001

   rec_lon

   longitude of the hydrophone at the receiver vessel (RVSL) (Source: producer defined)

   Range of values
   Minimum:	-122.337685
   Maximum:	-121.924577
   Units:	decimal degrees
   Resolution:	0.000001

   rec_lat

   latitude of the hydrophone at the receiver vessel (RVSL) (Source: producer defined)

   Range of values
   Minimum:	36.778772
   Maximum:	36.975878
   Units:	decimal degrees
   Resolution:	0.000001

   signoffset

   offset distance between the instrument layback position of the sparker source off the stern of the source vessel and the hydrophone receiver positioned below the receiver vessel. Positive values are when the source is northwest of the receiver and negative when the source is southeast of the receiver (Source: producer defined)

   Range of values
   Minimum:	-5356
   Maximum:	4736
   Units:	meters
   Resolution:	1

   y

   Year collected (Source: time stamp from GGA navigation string from source vessel R/V Parke Snavely)

   Range of values
   Minimum:	2021
   Maximum:	2021
   Units:	year collected
   Resolution:	1

   jd

   Julian Day collected (Source: time stamp from GGA navigation string from source vessel R/V Parke Snavely)

   Range of values
   Minimum:	111
   Maximum:	119
   Units:	Julian day collected
   Resolution:	1

   h

   hour collected (Source: time stamp from GGA navigation string from source vessel (RVPS))

   Range of values
   Minimum:	14
   Maximum:	20
   Units:	hour of day collected
   Resolution:	1

   m

   minute collected (Source: time stamp from GGA navigation string from source vessel (RVPS))

   Range of values
   Minimum:	0
   Maximum:	59
   Units:	minute of hour collected
   Resolution:	1

   s

   second collected (Source: time stamp from GGA navigation string from source vessel (RVPS))

   Range of values
   Minimum:	0
   Maximum:	59
   Units:	second of minute collected
   Resolution:	1

   us

   microsecond collected (Source: time stamp from GGA navigation string from source vessel (RVPS))

   Range of values
   Minimum:	68436
   Maximum:	932070
   Units:	microsecond of second of minute collected
   Resolution:	1

   utc_dt

   Coordinated Universal Time (UTC) Day Time string (Source: producer defined) Sequential unique whole numbers that are automatically generated. For example, 2021-04-23 18:31:02.999936+00:00 represents 2021-04-23 as the date collected and 18:31:02.999936+00:00 is the UTC time that the navigation point was taken

   rec_elev

   RVPS hydrophone receiver elevation below sea surface (Source: RBR solo depth logger fixed to TC4304 hydrophone receiver. Note that NaN values exist where no depth data was recorded.)

   Range of values
   Minimum:	-5.60
   Maximum:	-0.83
   Units:	depth in meters
   Resolution:	0.01

   lav

   largest absolute value amplitude seismic trace recorded by RVPS hydrophone (Source: largest absolute value SEG-Y seismic trace)

   Range of values
   Minimum:	0.000109
   Maximum:	0.073863
   Units:	SEG-Y amplitude
   Resolution:	0.000001

   lav_ms

   microsecond collected (Source: SEG-Y time of largest absolute amplitude seismic trace)

   Range of values
   Minimum:	3.038
   Maximum:	22.195999
   Units:	millisecond
   Resolution:	0.000001

   spllav

   sound pressure level largest amplitude value per SEG-Y seismic trace (Source: largest absolute value SEG-Y seismic trace)

   Range of values
   Minimum:	146.167186
   Maximum:	202.768536
   Units:	decibels
   Resolution:	0.000001

   sllav

   sound level largest amplitude value (Source: largest absolute value SEG-Y seismic trace)

   Range of values
   Minimum:	156.662893
   Maximum:	221.551818
   Units:	decibels
   Resolution:	0.000001

   mfspllav

   51 trace-mean filtered sound pressure level largest amplitude value per SEG-Y seismic trace (spllav attribute) (Source: largest absolute value SEG-Y seismic trace)

   Range of values
   Minimum:	172.663691
   Maximum:	195.877498
   Units:	decibels
   Resolution:	0.000001

   mfsllav

   51 trace-mean filtered sound level largest amplitude value per SEG-Y seismic trace (sllav attribute) (Source: largest absolute value SEG-Y seismic trace)

   Range of values
   Minimum:	193.327235
   Maximum:	215.487600
   Units:	decibels
   Resolution:	0.000001

   2021-619-FA_RVSL_SEGYpeakamplitude_csv.zip

   zip file containing 36 csv summary tables for each SEG-Y recorded with the hydrophone aboard the R/V San Lorenzo receiver vessel. The first line of the csv files is a header line. (Source: Producer defined)

   filename

   Name of navigation line (Source: Assigned unique line identifier name)

   Value	Definition
   SL-L25_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site
   SL-L25_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site
   SL-L25_S_c	Pass ‘c’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site
   SL-L25A_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the second 25-meter depth site ‘25A’
   SL-L25A_S_a2	Pass ‘a2’ (part two of pass a) with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site ‘25A’
   SL-L25A_S_a3	Pass ‘a3’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site ‘25A’
   SL-L25A_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 25-meter depth site ‘25A’
   SL-L50_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site
   SL-L50_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site
   SL-L50A_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site ‘50A'
   SL-L50A_S_a2	Pass ‘a2’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site ‘50A’
   SL-L50A_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 50-meter depth site ‘50A’
   SL-L100_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   SL-L100_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   SL-L100_S_c	Pass ‘c’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   SL-L100_S_c2	Pass ‘c2’ with the SIG ELP790 minisparker source (power 700 joules) at the 100-meter depth site
   SL-L200_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 200-meter depth site
   SL-L200_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 200-meter depth site
   SL-L200_S_c	Pass ‘c’ with the SIG ELP790 minisparker source (power 700 joules) at the 200-meter depth site
   SL-L200_D10_a	Pass ‘a’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site
   SL-L200_D10_b	Pass ‘b’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site
   SL-L200_D10_c	Pass ‘c’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site
   SL-L200_D10_d	Pass ‘d’ with the Delta sparker source (power 1.0 kilojoules) at the 200-meter depth site Enumerated_Domain_Value_Definition_Source: Producer defined
   SL-L600_S_a	Pass ‘a’ with the SIG ELP790 minisparker source (power 700 joules) at the 600-meter depth site
   SL-L600_S_b	Pass ‘b’ with the SIG ELP790 minisparker source (power 700 joules) at the 600-meter depth site
   SL-L600_D24_a	Pass ‘a’ with the Delta sparker source (power 2.4 kilojoules) at the 600-meter depth site
   SL-L600_D24_b	Pass ‘b’ with the Delta sparker source (power 2.4 kilojoules) at the 600-meter depth site

   hpid

   Hydrophone Identifier (Source: producer defined) model number CR3101 (Cetacean Research) model number CR3102 (Cetacean Research)

   lbsrc_lon

   longitude of the sparker source layback position from the stern of the source vessel (RVPS) (Source: producer defined)

   Range of values
   Minimum:	-122.361232
   Maximum:	-121.897050
   Units:	decimal degrees
   Resolution:	0.000001

   lbsrc_lat

   latitude of the sparker source layback position from the stern of the source vessel (RVPS) (Source: producer defined)

   Range of values
   Minimum:	36.763453
   Maximum:	36.992548
   Units:	decimal degrees
   Resolution:	0.000001

   rec_lon

   longitude of the hydrophone at the receive vessel (RVSL) (Source: producer defined)

   Range of values
   Minimum:	-122.337685
   Maximum:	-121.924577
   Units:	decimal degrees
   Resolution:	0.000001

   rec_lat

   latitude of the hydrophone at the receive vessel (RVSL) (Source: producer defined)

   Range of values
   Minimum:	36.778768
   Maximum:	36.975878
   Units:	decimal degrees
   Resolution:	0.000001

   signoffset

   offset distance between the layback position of the sparker source off the stern of the RVPS source vessel and the RVSL hydrophone receiver. Positive values are when the source is northwest of the receiver and negative when the source is southeast of the receiver (Source: producer defined)

   Range of values
   Minimum:	-5440
   Maximum:	4733
   Units:	meters
   Resolution:	1

   y

   Year collected (Source: time stamp from GGA navigation string from receiver vessel (RVSL))

   Range of values
   Minimum:	2021
   Maximum:	2021
   Units:	year collected
   Resolution:	1

   jd

   Julian Day collected (Source: time stamp from GGA navigation string from receiver vessel (RVSL))

   Range of values
   Minimum:	111
   Maximum:	119
   Units:	Julian day collected
   Resolution:	1

   h

   hour collected (Source: time stamp from GGA navigation string from receiver vessel (RVSL))

   Range of values
   Minimum:	14
   Maximum:	20
   Units:	hour of day collected
   Resolution:	1

   m

   minute collected (Source: time stamp from GGA navigation string from receiver vessel (RVSL))

   Range of values
   Minimum:	0
   Maximum:	59
   Units:	minute of hour collected
   Resolution:	1

   s

   second collected (Source: time stamp from GGA navigation string from receiver vessel (RVSL))

   Range of values
   Minimum:	0
   Maximum:	59
   Units:	second of minute collected
   Resolution:	1

   us

   microsecond collected (Source: time stamp from GGA navigation string from receiver vessel (RVSL))

   Range of values
   Minimum:	68156
   Maximum:	932070
   Units:	microsecond of second of minute collected
   Resolution:	1

   utc_dt

   Coordinated Universal Time (UTC) Day Time string (Source: producer defined) Sequential unique whole numbers that are automatically generated. For example, 2021-04-23 18:31:02.999936+00:00 represents 2021-04-23 as the date collected and 18:31:02.999936+00:00 is the UTC time that the navigation point was taken.

   rec_elev

   RVSL receive vessel hydrophone elevation (depth below surface) (Source: RBR solo depth logger attached at hydrophone receiever. Note that NaN values exist where no depth data was recorded.)

   Range of values
   Minimum:	-20.75
   Maximum:	-9.45
   Units:	depth in meters
   Resolution:	0.01

   lav

   largest absolute amplitude value for each seismic trace recorded by hydrophone on receive vessel (Source: R/V San Lorenzo receive SEG-Y files)

   Range of values
   Minimum:	0.000057
   Maximum:	0.150862
   Units:	amplitude
   Resolution:	0.000001

   lav_ms

   time in milliseconds of the largest absolute amplitude value for each seismic trace (Source: R/V San Lorenzo receive SEG-Y files)

   Range of values
   Minimum:	24.427999
   Maximum:	4342.666016
   Units:	milliseconds
   Resolution:	0.000001

   spllav

   sound level largest amplitude value (Source: largest absolute value SEG-Y seismic trace)

   Range of values
   Minimum:	123.654745
   Maximum:	192.171604
   Units:	depth in meters
   Resolution:	0.01

   mfspllav

   51 trace-mean filtered sound pressure level at the largest amplitude value sample (Source: mean filtered)

   Range of values
   Minimum:	129.476535
   Maximum:	187.471121
   Units:	depth in meters
   Resolution:	0.01

   2021-619-FA_peakamplitude_scatter_plots.zip

   Zip file containing 9 SEG-Y peak amplitude summary plots, one per depth site and sparker source (SIG minisparker: L25, L25A, L50, L50A, L100, L200, L600 and Delta sparker: L200 and L600) in PNG format. Each plot contains an upper scatter plot of sparker source and receiver sound pressure levels shown as a function of offset in meters from the sparker source. Each plot also contains a lower plot of receiver hydrophone sound pressure level shown as a function of offset in meters from the sparker source, which is referenced to the spherical divergence curve calculated using the mean measured source sound level for all passes at each depth station. These plotted data are taken from the R/V Parke Snavely (source) and R/V San Lorenzo (receiver) peak amplitude csv files contained in the 2021-619-FA_RVPS_SEGYpeakamplitude_csv.zip and 2021-619-FA_RVSL_SEGYpeakamplitude_csv.zip zip files previously described. (Source: Producer defined)

   2021-619-FA_peakamplitude_MeanFilterCurve_plots.zip

   Zip file containing 9 SEG-Y peak amplitude summary plots, one per depth site and sparker source (SIG minisparker: L25, L25A, L50, L50A, L100, L200, L600 and Delta sparker: L200 and L600) in PNG format. Each plot contains an upper plot of 51-trace mean filtered sparker source and receiver sound pressure levels shown as a function of offset in meters from the sparker source. Each plot also contains a lower plot of 51-trace mean filtered receiver hydrophone sound pressure levels shown as a function of offset in meters from the sparker source, which is referenced to the spherical divergence curve calculated using the mean measured source sound level for all passes at each depth station. These plotted data are taken from the R/V Parke Snavely (source) and R/V San Lorenzo (receiver) peak amplitude csv files contained in the 2021-619-FA_RVPS_SEGYpeakamplitude_csv.zip and 2021-619-FA_RVSL_SEGYpeakamplitude_csv.zip files previously described. (Source: Producer defined)

   Entity_and_Attribute_Overview: The first line of the csv file is a header line.
   Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Alicia F. Balster-Gee
   • Wayne E. Baldwin
   • Patrick E. Hart
2. Who also contributed to the data set?
   The authors acknowledge our fellow participants of the sparker testing field activity 2021-619-FA (Pete Dal Ferro, Gerry Hatcher, Jared Kluesner, Rachel Marcuson, Jenny McKee, Dan Powers and Rob Wyland) and our team involved in survey planning and execution (Jackson Currie, William Danforth, Jane Denny, Tim Elfers, Dave Foster, Nathan Miller, Eric Moore and Carolyn Ruppel).
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?

   SrcNav (source 1 of 4)

   Balster-Gee, Alicia F., Baldwin, Wayne E, and Hart, Patrick E., 2022, R/V Parke Snavely (source vessel) navigation and survey geometry from USGS field activity 2021-619-FA collected in April of 2021 offshore Santa Cruz, CA: U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9EHITBI

   Type_of_Source_Media: online data
   Source_Contribution:

   Navigation from the source vessel was used to calculated the offset between the sound source and the hydrophone on the receiver vessel

   RecNav (source 2 of 4)

   Balster-Gee, Alicia F., Baldwin, Wayne E, and Hart, Patrick E., 2022, R/V San Lorenzo (receive vessel) navigation and survey geometry from USGS field activity 2021-619-FA collected in April of 2021 offshore Santa Cruz, CA: U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9EHITBI

   Type_of_Source_Media: online data
   Source_Contribution:

   Navigation from the receiver vessel was used to calculated the offset between the sound source and the hydrophone on the receiver vessel

   SrcSegy (source 3 of 4)

   Balster-Gee, Alicia F., Baldwin, Wayne E, and Hart, Patrick E., 2022, Marine sparker source SEG-Y seismic data recorded aboard the R/V Parke Snavely during USGS field activity 2021-619-FA offshore Santa Cruz, California in April of 2021: U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9EHITBI

   Type_of_Source_Media: online data
   Source_Contribution:

   SEG-Y data from the near-field hydrophone on the source vessel were used to calculate peak amplitudes

   RecSegy (source 4 of 4)

   Balster-Gee, Alicia F., Baldwin, Wayne E, and Hart, Patrick E., 2022, Marine sparker SEG-Y seismic data recorded aboard the R/V San Lorenzo using receive hydrophones during USGS field activity 2021-619-FA offshore Santa Cruz, California in April of 2021: U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9EHITBI

   Type_of_Source_Media: online data
   Source_Contribution:

   SEG-Y data from the hydrophone on the receiver vessel were used to calculate peak amplitudes

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

   Date: 27-Apr-2021 (process 1 of 5)

   Aboard the source vessel (R/V Parke Snavely; RVPS), sparker source (either the SIG ELP790 or the Applied Acoustics Delta Sparker) was towed on a 20-meter cable from the stern of the source vessel (R/V Parke Snavely; RVPS) along seven planned survey tracklines in water depths ranging from 25 to 600 meters. The SIG ELP790 sparker was powered at 700 joules at all water depths. The Applied Acoustics Delta Sparker was powered at 1000 joules at the 200-meter depth site and powered at 2.4 kilojoules at the 600-meter depth site. A Reson TC4034 hydrophone and an RBR depth logger were towed on a second cable and positioned in the water just below the sparker to measure the near-field outgoing source signal and depth. Continuous waveform data (TDMS format) from the near-field hydrophone were acquired using SignalExpress software sampling at 192 kHz. A second, receiver vessel (R/V San Lorenzo; RVSL), maintained a nearly stationary position at the midpoint of each trackline and recorded the signal on another hydrophone hanging in the water at mid-vessel. A unique code name was given to each navigation line where PS=the source vessel R/V Parke Snavely; L=line followed by 2- or 3-numerals representing the water depth (the water depth may be followed by an A denoting a planned replicate transect line); S=SIG ELP790 700-joule minisparker source, D10=1.2 kilojoule Delta sparker source, or D24=2.4 kilojoule Delta sparker source; subsequent passes are followed with a, b, c, d, and a numeral as needed. The source and receiver vessels’ navigation data (SrcNav, RecNav) and hydrophone signal data (SrcSegy, RecSegy) are provided elsewhere in these data release.

   Date: 27-Apr-2021 (process 2 of 5)

   Navigational data from both the source and receiver vessels were recorded in raw GGA format. The UTC timestamp, latitude and longitude were extracted using a series of Python notebooks. The layback position of the sparker source was estimated to be 20 meters from the stern of the source vessel based on the length of the cable. The python tool PyProj.Geod WGS84 was used to merge the data frames of the source layback latitude and longitude positions (lbsrc_lat and lbsrc_lon, respectively) and to calculate and assign the offset distance, in meters, between the sparker source and the hydrophone hanging below the receiver vessel for each UTC time sample (utc_dt). To orient the offsets from separate passes relative to each other, a signed offset (signoffet) value was assigned in which the source offset value is positive when the source vessel (RVPS) was northwest of the receiver vessel (RVSL) and negative when the source vessel is southeast of the receiver vessel. Data sources used in this process:

   • SrcNav
   • RecNav

   Date: 27-Apr-2022 (process 3 of 5)

   SignalExpress software was used to output TDMS float files from the Reson TC4034 hydrophone on the source vessel (RVPS). The python package npTDMSb (https://nptdms.readthedocs.io/en/stable/apireference.html#module-nptdms) was used to read the recorded hydrophone float voltage and write to an ObsPy trace (https://docs.obspy.org). Aboard the receiver vessel (RVSL), SpectraPlus .wav files were output in 16-bit format from the Cetacean Research model CR3 receiver hydrophones. ObsPy and NumPy (https://numpy.org) python packages were used to unscale the 16-bit voltage readings to float format ObsPy traces. For each pass at each depth site, the timing of the electromagnetic spike as the power supply (aboard the source vessel) discharges power to the sparker source relative to the nearest offset shot time was used to shift the continuous waveform start time. For both source and receiver ObsPy traces, a 70-7000Hz bandpass filter was applied. ObsPy traces were sliced from the continuous waveform using the shot timing (record lengths for RVPS SEG-Y are 0.2 seconds and the RVSL SEG-Y are 2 seconds with offset dependent start times written to the Delay Recording time DELRT header in header bytes 109-110), resampled to 16 kHz, and standard SEG-Y headers were written (https://seg.org/Portals/0/SEG/News%20and%20Resources/Technical%20Standards/seg_y_rev1.pdf). The source and receiver vessel navigation, shot times, and RBR hydrophone depths (when recorded) were written to SEG-Y headers.

   Date: 27-Apr-2022 (process 4 of 5)

   SEG-Y data files were imported into Shearwater Reveal seismic software (https://www.shearwatergeo.com/4/reveal-software) where data were viewed for quality control. The peak absolute value amplitude per seismic trace was selected (csv attribute lav) and the time of the sample point was recorded in milliseconds (csv attribute lav_ms). Using equations 3 and 5 from NUWC-NPT Technical Report 12, 203 24 March 2016 (Crocker and Fratantonio, 2016), Sound Pressure Level (SPL), field pressure, and Sound Level (SL) were calculated from the largest absolute value trace amplitudes as well as the calibrated hydrophone sensitivities (CR3101 = -208.2; CR3102 = -208.6; TC4034-3 = -225.4). These values were mean filtered over 51-traces to represent the overall trend of Sound Pressure Level decay as a function of offset distance from the sparker sound source. These data were exported in csv format and merged with the source and receiver navigation, shot times, and RBR hydrophone depths (when recorded). Data sources used in this process:

   • SrcSegy
   • RecSegy

   Data sources produced in this process:

   • SrcPeakAmp
   • RecPeakAmp

   Date: 27-Apr-2022 (process 5 of 5)

   CSV data were plotted in PNG format per depth site in a final python notebook using tools SciPy (https://scipy.org), NumPy (https://numpy.org) and Matplotlib (https://matplotlib.org). Receiver sound pressure level (csv attribute spllav) was plotted as a function of offset (csv attribute signoffset) and source sound level (sllav) also plotted as a function of offset (signoffset) are plotted in the upper portion of each scatter plot contained in the zip file ‘2021-619-FA_peakamplitude_scatter_plots.zip’. The mean source calculated sound level (referenced to 1-meter distance) was calculated for all passes and source types for each depth site and is noted in the legend as well as the published sound level for each sparker model. A lower scatter plot in the same PNG image displays the receiver sound pressure level measurements with the spherical divergence reference calculated using the mean measured sound level as a function of offset. These same data, 51-trace mean filtered, are plotted in the PNG images contained in the zipfile ‘2021-619-FA_peakamplitude_MeanFilterCurve_plots.zip’ using the mean filtered csv attributes mfspllav and mfsllav, mean-filtered sound pressure level and sound level, respectively. Data sources used in this process:

   • SrcPeakAmp
   • RecPeakAmp

3. What similar or related data should the user be aware of?
   Crocker, Steven E., and Fratantonio, Frank D., 2016, Characteristics of Sound Emitted During High-Resolution Marine Geophysical Surveys.

   Online Links:

   • https://espis.boem.gov/final%20reports/5551.pdf

   Other_Citation_Details:

   Crocker, S.E. and Fratantonio, F.D., 2016, Characteristics of Sound Emited During High-Resolution Marine Geophysical Surveys: NUWC-NPT Technical Report 12,203, Bureau of Ocean Energy Management 2016-044.

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

1. How well have the observations been checked?
   The Reson TC4304 hydrophone, a broad band spherical hydrophone that provides uniform omni-directional characteristics between 1Hz and 480kHz (http://www.teledynemarine.com/reson-tc-4034), was calibrated on 2014-01-13 by the manufacturer and measured a sensitivity of -225.4dB. The SIG ELP790 sparker was operated at 700 joules (https://www.marine-seismic-equipments.net/sparker-sound-sources/). The Applied Acoustics Delta Sparker (https://www.subseatechnologies.com/applied-acoustics/sub-bottom-profiling/sound-source-sparker/delta-sparker/) was operated at 1000 joules at the 200-meter depth site and at 2400 joules at the 600-meter depth site. For both sparker sources operated at the stated power levels, the Reson TC3404 hydrophone was positioned properly to record the full spectrum of sound output. Cetacean Research CR3 hydrophones CR3101 and CR3102 have measured sensitivities of -208.2db and -208.6dB, respectively. RBR solo depth loggers have a stated accuracy of +/-0.05 percent full scale (about 1 cm water depth).
2. How accurate are the geographic locations?
   An Applanix POS-MV (Position and Orientation System for Marine Vessels) Elite was used to position the source vessel during data collection. The Applanix POS-MV Elite has a stated positional accuracy of 0.5-2 meters (https://www.applanix.com/downloads/products/specs/posmv/POS-MV-ELITE.pdf). A Garmin GPSMAP 4212 Differential Global Positioning System (DGPS; https://www.garmin.com/en-US/p/8114) was used to position the receiver vessel during data collection. The Garmin GPSMAP has a stated accuracy within 5 to 10 meters. Accuracies of final products may be lower due to total propagated uncertainties of the mapping systems, which include position and motion compensation system, navigation, as well as data processing that includes calculating the source layback from the stern of the vessel (20 meters), and PyProj.Geod calculation of offset distance between the sparker source position and the position of the receive hydrophone.
3. How accurate are the heights or depths?
   Two-way travel time in milliseconds referenced to sea level is recorded in SEG-Y files. RBR Solo-D depth loggers were mounted with the hydrophones for most of the survey lines to estimate depths with the RBR Ltd. Ruskin utility (v2.7.3.201905031233) via the simplified derivation, where depth in meters = (measured pressure in dbar - atmospheric pressure (set to default 10.1325 dbar)) / (density (set to default 1.0281 g/mL) * 0.980665). The RBR Solo-D units used are rated to 20 meters and RBR Ltd. state that they are accurate to +/- 0.05 percent of full scale (about 1 cm water depth). If this depth information was recorded, it is populated in rec_elev column of the csv files. If this receiver elevation data was not recorded, a NaN value populates the column.
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   Quality control was conducted during processing to ensure consistency of SEG-Y hydrophone receiver data recorded aboard the receiver vessel, and of depths recorded by the RBR solo depth loggers. The position of the sound source (data available elsewhere in these data release) is contained in each csv file in the lbsrc_lon and lbsrc_lat columns. The position of the hydrophone receiver aboard the receiver vessel is recorded in the csv rec_lon and rec_lat columns in decimal degrees.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - CMGDS

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov
2. What's the catalog number I need to order this data set? Peak amplitude data are presented in csv format for each pass. Data from the source and receiver vessels are zipped together separately (2021-619-FA_RVPS_SEGYpeakamplitude_csv.zip and 2021-619-FA_RVSL_SEGYpeakamplitude_csv.zip, respectively). The corresponding summary plots of recorded peak amplitude sound pressure levels as a function of offset from the sparker source are presented as scatter plots and as 51-trace mean filtered plots contained in two separate zip files (2021-619-FA_peakamplitude_scatter_plots.zip and 2021-619-FA_peakamplitude_MeanFilterCurve_plots.zip, respectively). These plots are organized by depth site and sparker source type, containing all recorded passes, and are presented in PNG format.
3. What legal disclaimers am I supposed to read?
   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	Zip file contains 30 csv files in format comma-delimited text (version RFC 4180) Size: 1.0
     Network links:	https://doi.org/10.5066/P9EHITBI

     Data format:	Zip file contains 36 csv files in format comma-delimited text (version RFC 4180) Size: 1.2
     Network links:	https://doi.org/10.5066/P9EHITBI

     Data format:	Zip file contains 9 PNG images in format PNG (version ImageMagick (version 7.0.8-11)) Portable Network Graphic (PNG) Size: 3.8
     Network links:	https://doi.org/10.5066/P9EHITBI

     Data format:	Zip file contains 9 PNG images in format PNG (version ImageMagick (version 7.0.8-11)) Portable Network Graphic (PNG) Size: 2.3
     Network links:	https://doi.org/10.5066/P9EHITBI

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?
   CSV data can be viewed with any text editing or spreadsheet software. PNG images can be viewed with any image viewing software.

Who wrote the metadata?

Dates:

Last modified: 20-Sep-2022

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)