Aqua TROLL 600 sensor data for four sites in the Grand Bay National Estuarine Research Reserve, Mississippi, estuary from February 2022 through January 2023

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Frequently anticipated questions:


What does this data set describe?

Title:
Aqua TROLL 600 sensor data for four sites in the Grand Bay National Estuarine Research Reserve, Mississippi, estuary from February 2022 through January 2023
Abstract:
To better understand sediment deposition in marsh environments, scientists from the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center (USGS-SPCMSC) selected five marsh study sites (Sites 5, 6, 7, 8, and 9) and four nearshore estuarine study sites (Sites 8S, 8D, 9S, 9D) along the Point Aux Chenes Bay shoreline of the Grand Bay National Estuarine Research Reserve (GNDNERR), Mississippi. This study builds on Smith and others (2020b) and includes datasets collected after the installation of a living shoreline (a subtidal sill [artificial reef]) that was completed in May 2021. Each marsh site consisted of five plots located along a transect perpendicular to the marsh-estuary shoreline at 5-meter (m) increments (5, 10, 15, 20, and 25 m from the shoreline). Each plot contained three to six net sedimentation tiles (NST) that were secured flush to the marsh surface using polyvinyl chloride (PVC) pipe. NST are an inexpensive and simple tool to assess short- and long-term deposition that can be deployed in highly dynamic environments without the compaction associated with traditional coring methods. The NST were deployed for three-month sampling periods, measuring sediment deposition from August 2021 to January 2023. Sediment deposited on the NST were processed to determine physical characteristics, such as deposition thickness, volume, wet weight/dry weight, grain size, and organic content (via loss-on-ignition [LOI]). For select sampling periods, ancillary data (water level, elevation, and vegetation) are also provided in this data release. The estuarine sites consisted of Site 8S (shallow; landward of the subtidal sill), 8D (deep; seaward side of the subtidal sill), as well as 9S and 9D (both sites established adjacent to 8S/8D and the subtidal sill). During select trips water parameters (e.g., waves, water level, and turbidity) were collected at each estuarine site to collect turbidity and wave data. Data presented in this data release were collected under three USGS Field Activities Numbers (FAN; one FAN per year) during thirteen sampling trips (alternate FAN; each sampling trip was assigned a unique alt FAN under the main FAN): 2021-320-FA (21CCT01, 21CCT03, 21CCT04, 21CCT05), 2022-302-FA (22CCT01, 22CCT02, 22CCT03, 22CCT04, 22CCT05, 22CCT06, 22CCT07, 22CCT08) and 2023-301-FA (23CCT01), however, every trip does not contain all data types. This data release also contains data for 2020-323-FA (20CCT02) that was collected as a special collection trip for Hurricane Delta. This data was collected before the subtidal sill was installed and is being published with this data release since pre-subtidal sill data was already published. Additional survey and data details are available from the U.S. Geological Survey Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/. Users can look up USGS FANs in the CMGDS by replacing the FAN in the following url: https://cmgds.marine.usgs.gov/services/activity.php?fan=2022-302-FA. Data from a related NST study in the GNDNERR (Middle Bay and North Rigolets) can be found in Smith and others (2020a). Data collected from before the living shoreline (subtidal sill) installation can be found in Smith and others (2020b). For additional information on data processing and analysis, refer to the accompanying journal publication Smith and others (2025). Please read the full metadata for details on data collection, dataset variables, and data quality.
Supplemental_Information:
USGS scientists collected data from Aqua TROLL 600 sensors during a total of eight surveys. The general site locations were: 8S (30.3370, -88.4462), 8D (30.3359, -88.4441), 9S (30.3353, -88.4471), and 9D (30.3337, -88.4449). The BaroTROLL was deployed nearby at the GNDNERR office (30.4291, -88.4278). Data were downloaded following field visits. Each field visit was assigned a FAN and shortened alternate FAN (alt-FAN) by the USGS. This publication contains data for field activities from: 2022-302-FA (22CCT02, 22CCT03, 22CCT04, 22CCT05, 22CCT06, 22CCT07, 22CCT08) and 2023-301-FA (23CCT01). The deployment date and time, retrieval date and time, location, sensor serial number, and depth at retrieval can all be found in "AquaTroll_RBR_sensor_info.csv". The data are displayed in a comma-separated values (CSV) text file format. Due to sensor malfunction, some data may be missing from data files. BaroTROLL data was merged with the Aqua TROLL data and is published as a column in "AquaTroll_compiled_data.csv".
  1. How might this data set be cited?
    Smith, Kathryn E.L., Terrano, Joseph F., Ellis, Alisha M., Smith, Kathryn E.L., Griffiths, Jonathan P., and Virden, Matthew, 20250527, Aqua TROLL 600 sensor data for four sites in the Grand Bay National Estuarine Research Reserve, Mississippi, estuary from February 2022 through January 2023:.

    This is part of the following larger work.

    Terrano, Joseph F., Ellis, Alisha M., Smith, Kathryn E.L., Pitchford, Jonathan, Archer, Michael, Vargas, Joseph M., Griffiths, Jonathan P., Randall, Samuel M., Virden, Matthew, Everhart, Cheyenne S., and Sparks, Eric, 20250527, Shore Proximal Marsh Sediment Deposition and Ancillary Data From Grand Bay National Estuarine Research Reserve, Mississippi, From October 2020 to January 2023: U.S. Geological Survey data release doi:10.5066/P13VT3ET, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -88.4474
    East_Bounding_Coordinate: -88.4435
    North_Bounding_Coordinate: 30.3370
    South_Bounding_Coordinate: 30.3337
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 15-Feb-2022
    Ending_Date: 31-Jan-2023
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: tabular digital data
  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 (38)
    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 0.0197843295. Longitudes are given to the nearest 0.0229959585. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D WGS 1984.
      The ellipsoid used is WGS1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 0.0001
      Altitude_Distance_Units: meter
      Altitude_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    AquaTroll_compiled_data.csv
    CSV file of Aqua TROLL data collected in 2022 and 2023 from four estuarine sites in the Grand Bay National Estuarine Research Reserve, Mississippi. Data were collected using Aqua TROLL 600 Multiparameter Sondes. Missing data present in the data file, written as "NA" (and occasionally "0", when indicated), are regarded as sensor malfunction. (Source: USGS)
    Alt_FAN
    Alternate (abbreviated) FAN assigned for each sensor retrieval trip. (Source: USGS) Character string. Alternate FAN were assigned by the USGS and are YYCCTXX, where YY is the 2-digit year, CCT stands for coastal change and transport (a USGS project identifier), and XX is the trip number. For example, 22CCT01 was from 2022 sensor collection trip 01.
    Site
    Estuarine site the sensor was deployed at. (Source: USGS)
    ValueDefinition
    8SShallow; landward of the subtidal sill.
    8DDeep; seaward side of the subtidal sill.
    9SSouth of and adjacent to 8S and the subtidal sill.
    9DSouth of and adjacent to 8D and the subtidal sill.
    Serial_Num
    Aqua TROLL 600 serial number. (Source: USGS) Character string. Six-digit serial number of the Aqua TROLL 600.
    date.time
    Date in the M/DD/YYYY, MM/D/YYYY, M/D/YYYY or MM/DD/YYYY format and Coordinated Universal Time (UTC) in the H:MM or HH:MM format. Data were collected in 15-minute intervals. (Source: USGS)
    Range of values
    Minimum:02/15/2022 11:45
    Maximum:1/31/2023 16:00
    seconds
    Internal sensor collection time (seconds; s) (Source: USGS)
    Range of values
    Minimum:6300
    Maximum:4305655
    Units:seconds (s)
    act_cond
    Actual Conductivity (microsiemens per centimeter; µS/cm) (Source: USGS)
    Range of values
    Minimum:0
    Maximum:59188.34
    Units:microsiemens per centimeter (µS/cm)
    spec_cond
    Specific Conductivity (microsiemens per centimeter; µS/cm) (Source: USGS)
    Range of values
    Minimum:0
    Maximum:61277.23
    Units:microsiemens per centimeter (µS/cm)
    salinity
    Salinity (practical salinity units; PSU) (Source: USGS)
    Range of values
    Minimum:0
    Maximum:41.773
    Units:practical salinity units (PSU)
    resist
    Resistivity (ohm-centimeter; ohm-cm) (Source: USGS)
    Range of values
    Minimum:0
    Maximum:192365.2
    Units:ohm-centimeter (ohm-cm)
    water_dens
    Water Density (grams per cubic centimeter; g/cm3) (Source: USGS)
    Range of values
    Minimum:0.994
    Maximum:1.029
    Units:grams per cubic centimeter (g/cm3)
    turbidity
    Turbidity (in nephelometric turbidity units; NTU). Values of "0", "NA", or values above 4000 are erroneous. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:10140.37
    Units:nephelometric turbidity units (NTU)
    do_conc
    Dissolved Oxygen (concentration in milligrams per liter; mg/L). Aqua TROLL sensors can read DO concentrations from 0-60 mg/L. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:17.015
    Units:milligrams per liter (mg/L)
    do_sat
    Dissolved Oxygen (percent saturation; %Sat). Aqua TROLL sensors can read DO concentrations from 0-60 mg/L or the equivalent percentage (0-600%) of DO saturation in water. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:183.577
    Units:percent saturation (%Sat)
    par_press
    Partial Pressure Oxygen (Torr) (Source: USGS)
    Range of values
    Minimum:-0.387
    Maximum:286.133
    Units:Torr
    temp
    Temperature (degrees Celsius; C) (Source: USGS)
    Range of values
    Minimum:2.27
    Maximum:35.244
    Units:degrees Celsius (C)
    voltage
    External Voltage (volt; V) (Source: USGS)
    Range of values
    Minimum:0
    Maximum:2.162
    Units:volt (v)
    battery
    Battery percentage remaining (%) (Source: USGS)
    Range of values
    Minimum:74
    Maximum:99
    Units:percent (%)
    bar_press
    Barometric pressure collected by the BaroTROLL (millibar; mBar) (Source: USGS)
    Range of values
    Minimum:1012.581
    Maximum:1036.373
    Units:millibar (mBar)
    pressure
    Pressure (millibar; mBar). Pressure was automatically post-corrected using barometric data. Pressure is only available for sensors that had pressure capability (value is "NA" if not equipped). (Source: USGS)
    Range of values
    Minimum:20.287
    Maximum:289.377
    Units:millibar (mBar)
    depth
    Depth (meters; m). Depth was automatically calculated and post-corrected using barometric data. Depth is only available for sensors that had pressure capability (value is "NA" if not equipped). (Source: USGS)
    Range of values
    Minimum:0.201
    Maximum:2.902
    Units:meters (m)
    bar_press_corr
    Barometric pressure collected by the Aqua TROLL and corrected using the BaroTROLL data (millibar; mBar). If the sensor did not collect pressure, the value will be written as "NA" as no post processing correction could be completed. (Source: USGS)
    Range of values
    Minimum:1003.551
    Maximum:1036.627
    Units:millibar (mBar)
    turb_flag
    Values in the turbidity field that were flagged as potentially erroneous. There are several factors that impact turbidity, so these error codes provide a way to quickly identify data that may contain errors. (Source: USGS)
    ValueDefinition
    LLow turbidity values flagged using a moving window of 5 with a threshold mean value below 0.2, or if the turbidity value is "0" or "NA".
    XTurbidity values greater or less than 3 standard deviations of the mean, or above 4000 NTU.
    depth_c
    Depth corrected using the height of the sensor off the seafloor (meters; m). All sensors measured at 0.22 meters in height, so this field was calculated as "depth" + 0.22 m. Corrected depth is only available for sensors that had pressure capability (value is "NA" if not equipped). (Source: USGS)
    Range of values
    Minimum:0.421
    Maximum:3.122
    Units:meters (m)
    depth_navd
    Depth (meters; m) corrected to the North American Vertical Datum of 1988 (NAVD88). NAVD88-corrected depths were calculated by comparing the Aqua TROLL depth measurements to NOAA water level gauge data from the Bayou La Batre Bridge, Alabama gauge (NOAA Station ID: 8739803). Water level data for the same time period were downloaded and plotted against temporally coincident Aqua TROLL data. The slope of the ordinary least squares regression line provided an elevation correction which was then applied to the water level data to adjust it to NAVD88. In this region, 0 m NAVD88 is approximately 0.053 m mean sea level (MSL) based on the GNDNERR, Mississippi Sound MS Tidal Datums (NOAA Station ID: 8740166). NAVD88 corrected depth is only available for sensors that had pressure capability (value is "NA" if not equipped). (Source: USGS)
    Range of values
    Minimum:-0.71977
    Maximum:0.877421
    Units:meters (m)
    AquaTroll_RBR_sensor_info.csv
    CSV of RBR deployment and retrieval information collected in 2021, 2022, and 2023 from four estuarine sites in the Grand Bay National Estuarine Research Reserve, Mississippi. Some RBR data is also present in this data file. Refer to the Grand_Bay_RBR_Data.zip files and associated metadata for RBR-specific information. (Source: USGS)
    Deployment FAN
    USGS field activity number (FAN) assigned to the deployment trip. (Source: USGS) Character string. Each field visit was assigned a FAN by the USGS SPCMSC to assist with dataset tracking. The FAN consists of YYYY-XXX-FA, with YYYY being the 4-digit year, XXX being the trip number, and FA representing that it is a field activity. There are two FANs associated with this sensor deployments: 2021-320-FA and 2022-302-FA. FANs were used to describe the entire field effort of a project, so alternate FANs were used to differentiate between quarterly sampling trips.
    Deployment Alt-FAN
    Alternate (abbreviated) FAN number assigned each deployment trip. Several alternate FANs can fall under one overarching FAN. (Source: USGS) Character string. Alternate FAN numbers were assigned by the USGS and are YYCCTXX, where YY is the 2-digit year, CCT stands for coastal change and transport, and XX is the trip number. For example, 21CCT01 was from 2021 sample collection trip 01.
    Retrieval FAN
    USGS field activity number (FAN) assigned to the retrieval trip. The retrieval FAN is also the identifying FAN when referring to the data. (Source: USGS) Character string. Each field visit was assigned a FAN by the USGS SPCMSC to assist with dataset tracking. The FAN consists of YYYY-XXX-FA, with YYYY being the 4-digit year, XXX being the trip number, and FA representing that it is a field activity. There are three FANs associated with this dataset: 2021-320-FA, 2022-302-FA, and 2023-301-FA. FANs were used to describe the entire field effort of a project, so alternate FANs were used to differentiate between quarterly sampling trips.
    Retrieval Alt-FAN
    Alternate (abbreviated) FAN assigned each retrieval trip. The retrieval FAN is also the identifying FAN when referring to the data. Several alternate FANs can fall under one overarching FAN. (Source: USGS) Character string. Alternate FANs were assigned by the USGS and are YYCCTXX, where YY is the 2-digit year, CCT stands for coastal change and transport (a USGS project identifier), and XX is the trip number. For example, 22CCT01 was from 2022 sensor collection trip 01.
    Site
    Estuarine site the sensor was deployed at. (Source: USGS)
    ValueDefinition
    8SShallow; landward of the subtidal sill.
    8DDeep; seaward side of the subtidal sill.
    9SSouth of and adjacent to 8S and the subtidal sill.
    9DSouth of and adjacent to 8D and the subtidal sill.
    Deployment Date
    Date in the M/DD/YYYY, MM/D/YYYY, M/D/YYYY or MM/DD/YYYY format. (Source: USGS)
    Range of values
    Minimum:8/3/2021
    Maximum:12/21/2022
    Deployment Time (local)
    Local time in Central Standard Time (CST) or Central Daylight Time (CDT) in the H:MM or HH:MM format the sensor was deployed. Data were collected in 30-minute intervals. (Source: USGS)
    Range of values
    Minimum:9:20 AM
    Maximum:4:09 PM
    Retrieval Date
    Date in the M/DD/YYYY, MM/D/YYYY, M/D/YYYY or MM/DD/YYYY format. (Source: USGS)
    Range of values
    Minimum:9/28/2021
    Maximum:6/22/2024
    Retrieval Time (local)
    Local time in Central Standard Time (CST) or Central Daylight Time (CDT) in the H:MM AM/PM or HH:MM AM/PM format the sensor was retrieved. Data were collected in 30-minute intervals. If the exact retrieval time was not known, a general time of day descriptor such as "morning" was used instead. (Source: USGS)
    Range of values
    Minimum:7:57 AM
    Maximum:7:50 PM
    Deployment Latitude (WGS84)
    Latitude of the sensor platform in the World Geodetic System of 1984 (WGS84). Coordinates are presented in decimal degrees. (Source: USGS)
    Range of values
    Minimum:30.3337
    Maximum:30.3372
    Units:decimal degrees
    Deployment Longitude (WGS84)
    Longitude of the sensor platform in the World Geodetic System of 1984 (WGS84). Coordinates are presented in decimal degrees. (Source: USGS)
    Range of values
    Minimum:-88.4474
    Maximum:-88.4435
    Units:decimal degrees
    Approx Depth at Retrieval (meters)
    Approximate water depth when the sensors were retrieved. Retrieval data is included because the sensor was still recording at the time of collection, so sensor data can be checked against the measured depth. The depth is approximate due to the potential uncertainty introduced by waves and the moving boat. (Source: USGS)
    Range of values
    Minimum:0.92
    Maximum:2.95
    Units:meters
    Aqua TROLL S/N
    Serial number of the Aqua TROLL 600. Serial number is provided as a way to track sensor specific errors. Data in this field do not apply to the RBR data. Cells with "NA" indicate no sensor was deployed that trip. (Source: USGS) Character string containing the serial number of the Aqua TROLL 600.
    Aqua TROLL sensor height (centimeter)
    Height of the Aqua TROLL 600 sensor off the seafloor, in centimeters. Data in this field do not apply to the RBR data. Cells with "NA" indicate no sensor was deployed that trip. (Source: USGS)
    Range of values
    Minimum:22
    Maximum:22
    Units:centimeters
    RBR S/N
    Serial number of the RBRSolo3. Serial number is provided so that sensor-specific errors can be traced. (Source: USGS) Character string containing the serial number of the RBRSolo3.
    RBR Altitude at deployment (centimeter)
    Height of the RBRSolo3 pressure transducer off the seafloor, in centimeters. (Source: USGS)
    Range of values
    Minimum:13
    Maximum:20
    Units:centimeters
    Notes
    Additional notes about the information presented in the table. (Source: USGS) Character string additional notes about the information presented in the table.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Kathryn E.L. Smith
    • Joseph F. Terrano
    • Alisha M. Ellis
    • Kathryn E.L. Smith
    • Jonathan P. Griffiths
    • Matthew Virden
  2. Who also contributed to the data set?
    The authors would like to acknowledge the GNDNERR staff for their contributions in collecting and reviewing this data.
  3. To whom should users address questions about the data?
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    Attn: Kathryn E.L. Smith
    Research Ecologist
    600 4th Street South
    St. Petersburg, FL
    US

    (727) 502-8000 (voice)
    kelsmith@usgs.gov

Why was the data set created?

This dataset includes In-Situ Aqua TROLL 600 (henceforth referred to as Aqua TROLL) data obtained from four estuarine locations in Grand Bay, Mississippi. Sensors with and without pressure (depth) were used during this study. The Aqua TROLL 600 sensors measured conductivity, salinity, resistivity, turbidity, dissolved oxygen, temperature, and pressure (depth, if equipped). An In-Situ Rugged BaroTROLL (henceforth referred to as BaroTROLL) was also deployed near the sites to collect barometric data used in post processing.

How was the data set created?

  1. From what previous works were the data drawn?
    NOAA water level gauge data (source 1 of 1)
    National Oceanic and Atmospheric Administration, 2023, NOAA Tides and Currents: NOAA Tides and Currents, Online.

    Online Links:

    Type_of_Source_Media: comma separated value (csv) file
    Source_Contribution:
    Water level data from NOAA tide gauges were downloaded and compared with the Aqua TROLL depth measurements to generate NAVD88-corrected depths.
  2. How were the data generated, processed, and modified?
    Date: 2023 (process 1 of 3)
    During deployment trips, four Aqua TROLL 600 sensors were deployed on custom built concrete sensor platforms to record water parameters (conductivity, temperature, turbidity, salinity). The general site locations were: 8S (30.3370, -88.4462), 8D (30.3359, -88.4441), 9S (30.3353, -88.4471), and 9D (30.3337, -88.4449). The BaroTROLL was deployed nearby at the GNDNERR office (30.4291, -88.4278). The deployment date and time, retrieval date and time, location, sensor serial number, and depth at retrieval can all be found in "Aqua_Troll_RBR_sensor_info.csv". Locations are projected to the World Geodetic System of 1984 (WGS84) coordinate system. Prior to each deployment, the batteries, desiccant, and 0-rings were checked, and each sensor was programmed, using In-Situ software packages Win-Situ 5 (desktop) or Vu-Situ (mobile) following procedures set forth in In-Situ Inc. (2024a). Sensors were programmed to record at 15-minute intervals from a preset start data/time to when the sensor was collected and manually stopped. The sensors were wrapped in plastic wrap and copper foil to prevent biofouling. Aqua Troll sensors were mounted horizontally to a custom-built sensor deployment platform made of starboard and concrete. An RBR sensor was also vertically mounted on the platform to provide wave data (refer to the RBR data and metadata in this data release). The sensor platform was lowered to the seafloor and was positioned so the Aqua TROLL was parallel with the shoreline. The sensor height (height from the ground to the middle of the sensor) and water depth were collected for use in post-processing. Due to waves and the moving boat, the noted depths are regarded as a general depth as there is some error in the measurements. The sensor height was always calculated as 22 centimeters since the Aqua TROLLs were mounted the same way every trip and all the platforms were identical. The BaroTROLL was zip tied vertically to fence at the GNDNERR office roughly 3 feet off the ground. The BaroTROLL height was recorded as the height from the ground to the sensor head. Person who carried out this activity:
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    Attn: Joseph F. Terrano
    Physical Scientist
    600 4th Street South
    St. Petersburg, FL
    U.S.

    (727) 502-8047 (voice)
    jterrano@usgs.gov
    Data sources produced in this process:
    • AquaTroll_RBR_sensor_info.csv
    Date: 2023 (process 2 of 3)
    At set collection intervals, the Aqua TROLLs were retrieved, and a new set of sensors was deployed. The BaroTROLL was always collected, downloaded, and immediately redeployed within the same day. Following each retrieval, the Aqua TROLLs and BaroTROLL were removed from their respective sites, cleaned, and the data was downloaded using the In-Situ software package Win-Situ 5 (desktop) or Vu-Situ (mobile) using procedures set forth in In-Situ Inc. (2024a). Using the Win-Situ 5s BaroMerge tool, the Aqua TROLL and BaroTROLL data were merged and post processed to automatically calculate water depth. The depth-corrected file was exported as a CSV. Since the Aqua Troll and BaroTROLL data were merged, no individual BaroTROLL files are published as part of this data release. The sensors were used with the manufacturer’s calibrations. If necessary, sensor calibration and maintenance was conducted following the In-Situ user manuals. If there was suspected erroneous data, the sensor was checked using Quick Cal solution and 10 and 100 nephelometric turbidity unit (NTU) calibration standards sold by In-Situ. If the sensor passed all the calibration checks it was returned to service. If the senor did not pass, it was removed from service and the manufacturer was consulted. Person who carried out this activity:
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    Attn: Joseph F. Terrano
    Physical Scientist
    600 4th Street South
    St. Petersburg, FL
    U.S.

    (727) 502-8047 (voice)
    jterrano@usgs.gov
    Date: 2023 (process 3 of 3)
    At the end of this study, all the CSV files from each FAN were run through R codes to 1) rename and reorder the fields, 2) to correct depth using the sensor height, 3) correct the depth to the North American Vertical Datum of 1988 (NAVD88) using National Oceanic and Atmospheric Administration (NOAA) data, 4) flag potentially erroneous turbidity data, 5) add FAN, site, and sensor serial number information, and 6) merge all the individual FAN files into a single CSV file. NAVD88-corrected depths were calculated by comparing the Aqua TROLL depth measurements to NOAA water level gauge data from the Bayou La Batre Bridge, Alabama gauge (NOAA Station ID: 8739803). Water level data for the same time period were downloaded and plotted against temporally coincident Aqua TROLL data. The slope of the ordinary least squares regression line provided an elevation correction which was then applied to the water level data to adjust it to NAVD88. In this region, 0 m NAVD88 is approximately 0.053 m mean sea level (MSL) based on the GNDNERR, Mississippi Sound MS Tidal Datums (NOAA Station ID: 8740166). NAVD88-corrected depths are only available for sensors that had pressure capability. Erroneous turbidity readings were flagged using three methods 1) if the value was greater or less than 3 standard deviations of the mean or greater than 4000 Nephelometric Turbidity Units (NTU), 2) using a Moving window of 5 with a threshold mean value below 0.2 NTU, or 3) if the turbidity value was "0" or "NA". The final dataset was checked for accuracy. Individual sensor data were not checked in detail since it is being published as raw data directly from the sensor, apart from turbidity and depth. For additional information on data processing and analysis, refer to the accompanying journal publication Smith and others (2025). Person who carried out this activity:
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    Attn: Joseph F. Terrano
    Physical Scientist
    600 4th Street South
    St. Petersburg, FL
    U.S.

    (727) 502-8047 (voice)
    jterrano@usgs.gov
    Data sources used in this process:
    • NOAA water level gauge data
    Data sources produced in this process:
    • AquaTroll_compiled_data.csv
  3. What similar or related data should the user be aware of?
    Smith, Kathryn E.L., Terrano, Joseph F., Khan, Nicole S., and Stalk, Chelsea A., 20200226, Shore Proximal Sediment Deposition, Elevation, Turbidity, and Water Level Data for Four Sites in the Coastal Marsh at Grand Bay National Estuarine Research Reserve, Mississippi, From October 2016 Through October 2017: U.S. Geological Survey, St. Petersburg, Florida.

    Online Links:

    Other_Citation_Details: Smith and others (2020a)
    Smith, Kathryn E.L., Terrano, Joseph F., Pitchford, Jonathan, Brochard, Michael, Vargas, Joseph M., Atchia, Isabelle D., Everhart, Cheyenne S., and Smith, Christopher G., 20200713, Shore Proximal Marsh Sediment Deposition and Ancillary Data From Grand Bay National Estuarine Research Reserve, Mississippi, From July 2018 to January 2020: U.S. Geological Survey, St. Petersburg, Florida.

    Online Links:

    Other_Citation_Details: Smith and others (2020b)
    Inc., In-Situ, 20240709, In-Situ Aqua TROLL 600 Operator's Manual: In-Situ Inc., Fort Collins, CO.

    Online Links:

    Other_Citation_Details: In-Situ Inc. (2024a)
    Inc., In-Situ, 202405, In-Situ Aqua TROLL 500-600-700-800 Spec-Sheet: In-Situ Inc., Fort Collins, CO.

    Online Links:

    Other_Citation_Details: In-Situ Inc. (2024b)
    Smith, Kathryn E.L., Pitchford, Jonathan L., Sparks, Eric L., Archer, Michael J., Virden, Matthew F., Terrano, Joseph F., and Smith, Christopher G., 20250612, Evaluating the influence of constructed subtidal reefs on marsh shoreline erosion, sediment deposition, and wave energy: Estuaries and Coasts Volume 48, Article 128, Springer Nature, Online.

    Online Links:

    Other_Citation_Details: Smith and others (2025)

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

  1. How well have the observations been checked?
    Measurements for conductivity, salinity, resistivity, water density, total dissolved solids, turbidity, total suspended solids, dissolved oxygen, temperature, partial pressure, barometric pressure (internally collected data), and pressure, were derived from internal calculations from the sensor and were not altered in any way. Barometric data and was collected from nearby using a BaroTROLL. The Aqua Troll and BaroTROLL data were run through the In-Situ software Win-Situ to automatically calculate depth. Corrected depths (depth_c), which account for vertical distance off the seafloor, and National Oceanic and Atmospheric Administration (NOAA) corrected depth data (depth_navd) were calculated by USGS staff. All fields were visually checked to ensure the data were reasonable. Additional checks were conducted using R codes for depth and turbidity (see processing steps for more information). Sensor malfunction was a common problem during this study. So missing data, written as "0" or "NA" values, are be regarded as sensor malfunction. These data were not removed to ensure data integrity. Specific accuracy information can be obtained from In-Situ Inc. (2024b). Additionally, the 22CCT08 Site 8S collection times were all off by one minute. To correct this, the R code was updated to round the minute to the nearest 15-minute interval (##:00, ##:15, ##:30, ##:45). Location data were collected using a handheld Garmin GPSMAP 62stc. Vertical and horizontal positional error was not collected. The precise position of the sensor was not as important as the general location (landward of the subtidal sill, seaward of the subtidal sill). The sensor platform was also marked by several buoys to ensure the platform was easily found for retrieval. Comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies in data collection methods.
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Data files containing Aqua Troll 600 data, collected within the Grand Bay National Estuarine Research Reserve, Mississippi, are complete and contain both unaltered (e.g., depth), and corrected (e.g., depth_c and Depth_NAVD) data. Sensor malfunction was a common problem during this study. So missing data, written as "0" or "NA" values, are regarded as sensor malfunction. Potentially erroneous turbidity values were also flagged during post-processing (blank cells represent data that passed all post-processing checks). All other fields were published as-is using internally collected and corrected data. Erroneous data were not removed. Data were run through an R code to removed data from when the sensor was recording measurements out of the water. These data files are considered complete, unless otherwise noted by null data values. Some sensors were faulty or nearing the end of their life during the data collection. In those cases, all data for that trip and sensor will be listed as "0" or "NA". The sensor serial number is also provided so users could further understand if errors were one-time events or common to a specific sensor.
  5. How consistent are the relationships among the observations, including topology?
    Data was collected every 15 minutes from the time of deployment to the time of retrieval at Sites 8S, 8D, 9S, and 9D. Sensor malfunction was a common problem during this study. So missing data, written as "0" or "NA" values, are regarded as sensor malfunction. These data were not removed. Data from all FANs were merged into a single file for inclusion in this data release.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints No access constraints. Please see 'Distribution Information' for details.
Use_Constraints These data are marked with a Creative Common CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
    Attn: USGS SPCMSC Data Management
    600 4th Street South
    Saint Petersburg, FL
    United States

    727-502-8000 (voice)
    gs-g-spcmsc_data_inquiries@usgs.gov
  2. What's the catalog number I need to order this data set? AquaTroll_compiled_data.csv, AquaTroll_RBR_sensor_info.csv
  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 for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product name is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 18-Jun-2025
Metadata author:
U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
Attn: USGS SPCMSC Data Management
600 4th Street South
Saint Petersburg, FL
United States

727-502-8000 (voice)
gs-g-spcmsc_data_inquiries@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/GB_AquaTroll_2022_2023_Metadata.faq.html>
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