Locations of bottom photographs collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_PHOTOS.SHP)

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Frequently anticipated questions:

What does this data set describe?

Locations of bottom photographs collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_PHOTOS.SHP)
In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once established, variable leaf water-milfoil forms dense beds that can alter the limnologic characteristics of a waterbody, impacting natural lacustrine communities and their habitats. Variable leaf water-milfoil infestations also disrupt recreational uses of waterbodies and have negatively affected swimming, boating, fishing, and property values in and around several lakes and ponds in New Hampshire.
In 1965, Moultonborough Bay, Lake Winnipesaukee became the first waterbody in New Hampshire where variable leaf water-milfoil was observed. Variable leaf water-milfoil is native to the Southeastern and Midwestern areas of the United States where more alkaline waters appear to limit the growth of this plant. Outside its native range, however, it adapts well to the relatively acidic, low-alkalinity, and nutrient-poor conditions of oligotrophic lakes and bays similar to Moultonborough Bay.
In 2005, the New Hampshire Department of Environmental Services (NHDES) collaborated with the U.S. Geological Survey to investigate the distribution (presence and density) of variable leaf water-milfoil in Moultonborough Bay. This study utilized geophysical systems and conventional water-quality measurements to identify lake-floor environments that may provide suitable habitat for the establishment and growth of variable leaf water-milfoil. The results of the study are intended to assist resource managers in federal and state agencies by providing methods for detecting variable leaf water-milfoil and for identifying areas susceptible to infestation. Ultimately, this information may lead to early detection, prevention, and more effective mitigation strategies.
Field activity information for this cruise is available on-line through the U.S. Geological Survey Coastal and Marine Geoscience Data System https://cmgds.marine.usgs.gov/fan_info.php?fa=2005-004-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 2014, Locations of bottom photographs collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_PHOTOS.SHP): data release DOI:10.5066/F71N7Z4H, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Denny, J.F., Danforth, W.W., Worley, C.R., and Irwin, B.J., 2014, High-resolution geophysical and sample data collected in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005, USGS Field Activity 2005-004-FA: data release DOI:10.5066/F71N7Z4H, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.390778
    East_Bounding_Coordinate: -71.359645
    North_Bounding_Coordinate: 43.727299
    South_Bounding_Coordinate: 43.712030
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2005-004-FA/data/imagery/2005-004-FA_photolocs.jpg (JPEG)
    Thumbnail image of the location of bottom photographs collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire, 2005
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 27-Jul-2005
    Ending_Date: 28-Jul-2005Currentness_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 (36)
    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?
    Bottom photograph locations collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Source: U.S. Geological Survey)
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Feature geometry. (Source: Esri) Coordinates defining the features.
    Time of day of bottom photograph collection by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire, 2005, in 24-hr time, UTC. (HH:MM:SS). This time represents camera time. (Source: U.S. Geological Survey) Time of day, 24-hour time. Format: HH:MM:SS
    This is the time offset between camera time and GPS time in the format HH:MM:SS. A positive value means the appropriate GPS time is AFTER the image time. (Source: U.S. Geological Survey.)
    Formal codeset
    Codeset Name:Time of day, 24-hour time. Format: HH:MM:SS
    Codeset Source:U.S. Geological Survey
    X-coordinate representing location of sediment sample (WGS 84) (Source: U.S. Geological Survey)
    Range of values
    Y coordinate representing the location of sample (WGS84) (Source: U.S. Geological Survey)
    Range of values
    Julian Day during which bottom photographs were collected where Julian day is the integer number representing the interval of time in days since January 1 of the year of collection. (2005). (Source: U.S. Geological Survey)
    Range of values
    Calendar year in which the bottom photographs were collected. (Source: U.S. Geological Survey)
    Range of values
    Filename of the bottom photograph stored in JPEG image format. (Source: U.S. Geological Survey) Filename of bottom photograph stored in JPEG format. Format: STA#.JPG, where the STA# represents the sample location .
    GPS time of day of bottom photograph collection. This time incorporates any offset from camera time. This time is UTC in the format HH:MM:SS. (Source: U.S. Geological Survey) Time of day, 24-hour time. Format: HH:MM:SS
    This represents the time difference (in seconds) between the camera time (TIME) and the navigation time (GPSTIME). A value other than zero (and usually greater than 5), often indicates a gap in the recorded navigaiton. (Source: U.S. Geological Survey)
    Range of values
    Unique USGS Cruise Identification. (Source: U.S. Geological Survey) Unique USGS Cruise identification. Format: YEAR_CRUISEID_FA where year is the calendar year of data collection, Cruise ID is the unique USGS field identifier, and FA is Field Activity (2005-004-FA).
    System used to collect the bottom photographs. (Source: U.S. Geological Survey) SEABed Observation and Sampling System (SEABOSS), USGS bottom video, photograph, and grab sampler sampling system.

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?
    Jane F. Denny
    U.S. Geological Survey
    384 Woods Hole Road
    Woods Hole, Massachusetts

    508-548-8700 x 2311 (voice)
    508-457-2310 (FAX)

Why was the data set created?

This data set includes a point shapefile of the locations of bottom photographs collected within Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 during USGS field activity 2005-004-FA. The bottom photographs were collected to ground-truth the geophysical data collected and used to characterize the surficial sediment and bottom habitat of the lakefloor. JPEG images of the bottom photographs are included in the distribution file (2005-004-FA_photos.zip)

How was the data set created?

  1. From what previous works were the data drawn?
    none (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, Bottom Photographs.

    Type_of_Source_Media: online
    The Mini SEABOSS was designed specifically for the USGS Woods Hole Science Center's 26-foot research vessel Rafael. This system is equipped with two video cameras, a digital still camera, and a Van Veen grab sampler. This system, weighing approximately 200 lbs., can be used to depths up to 40 meters. The grab itself is raised and lowered with a 3/16-inch Aramid fiber winch-line with a breaking strength of 5,600 pounds. The davit is secured when the Mini SEABOSS is in the water. The electrical cable is on a spring-wound take-up reel with electrical slip rings that is mounted aft of the sampler. This arrangement protects the 0.38-in. multi-conductor cable and keeps the Mini SEABOSS correctly oriented with the boat. This multi-conductor cable enables communication between the ship's lab and the Mini SEABOSS system. The digital camera, a Minolta Dimage 7Hi, is mounted in a machined Delrin housing with a flat port and is set for 2560 x 1920 pixel images at the "fine" setting for compression. This allows the camera to be used for over 200 images with a 1 GB Compact Flash card without downloading. The system also has a 50 Watt/second flash unit powered by 8 AA batteries. Two battery-powered lasers are set 15 cm apart for scale measurements. The red laser dots can usually be seen in the photo depending on the bottom type and the distance to the sea floor. A third battery powered laser is positioned at an angle so that when it intersects the other lasers, the Mini SEABOSS is at the optimum height off the bottom for a still photograph (optimal height is generally 75 cm above the bottom). The camera is set to a manual focus and set to a default focus distance (50 cm) once the camera is powered up. The default focus distance is slightly less than the optimum height above the seafloor to account for optical distortion under water.
    Video images were collected at 40 sample locations and digital photographs were collected at 36 of the 40 sample locations using the USGS Mini SEABOSS (Blackwood and Parolski, 2001). The sample locations were selected based on variation in the acoustic backscatter within the sidescan-sonar mosaic, with the objective of characterizing broad areas of different backscatter intensity. With the Mini SEABOSS deployed, the research vessel was allowed to drift with occasional power from the vessel to control drift direction. Video was collected over a total of 696 meters of lakefloor. Video drift position was derived from the HYPACK navigation files based on the start and end times of the drift. For some portions of the drift, there was no navigation, so the position was derived from the time and position in the video at 30-s intervals. Latitude and Longitude for sample locations 1 and 8 were derived solely from the video as HYPACK files were not saved to disk at these sample locations. Bottom photographs were generally taken immediately prior to collecting a sediment sample with the SEABOSS. A unique navigation position was not recorded when the bottom photographs were collected, however the time of photo collection was recorded.
    Grab samples of the surficial sediment were collected at 39 sample locations, typically at the end of a drift. Sample location 26 was not sampled, as the sediment was too coarse (boulders). However, bottom photographs and video were collected. The upper 2 cm of sediment was scraped from the surface of sediment samples for texture analysis. At sample locations 1 and 7, two sub-samples were collected due to the apparent bi-modal nature of the lakefloor and sample. One sub-sample was collected from the upper 2 cm, and the 2nd sub-sample was collected from the base of the sample (2 to 10 cm depth). (Two individual sites were occupied at Station 1, whereas only one site was occupied at Station 7. The one sample collected at Station 7 was subsequently sub-sampled). Sediment samples were collected at locations with relatively fine-grained sediment (sand or mud). Samples were not collected in gravel or cobble areas where gravel prevented full closure of the sampler and resulted in a washed-out sample (sample location 26).
    A total of 41 bottom samples were submitted for grain-size analysis. Grain-size analysis was performed at the USGS Sediment Laboratory at WHCMSC using methods described by Poppe and others (2005).
    Note: A small bit of water entered the camera housing during survey operations. This is reflected as a blurred 'dot' on the bottom photographs. The camera remained operational and data collection continued despite the 'water mark'.
  2. How were the data generated, processed, and modified?
    Date: 2005 (process 1 of 5)
    Bottom photographs were collected with the mini SEABOSS (Blackwood and Parolski, 2001) at 36 sample stations in Moultonborough Bay, Lake Winnipesaukee, New Hampshire, 2005.
    This and all subsequent processing steps were conducted by Jane F. Denny. Person who carried out this activity:
    Jane F. Denny
    U.S. Geological Survey
    384 Woods Hole Road
    Woods Hole, Massachusetts

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    Date: 2005 (process 2 of 5)
    The digital images were recorded on a compact flash card within the camera. Digital images were downloaded to a local disk and stored with a naming convention based on the station location. For example, sta11.jpg, is a bottom photograph collected at station (i.e. sample location) 11. Generally, only one bottom photograph was collected at each sample location. Nero Multimedia Software (version 2005) was used for the transfer and file naming.
    Date: 2013 (process 3 of 5)
    The time each bottom photograph was taken was stored in the EXIF header of the JPEG image. Python scripts were used to extract the times from the EXIF headers (JPEG_exifextract_gui_sort.py), parse the navigation from the raw HYPACK files for each Julian Day (parseHypackFolder_gui_sort_all.py), and use the HYPACK navigation to assign a unique latitude and longitude position for each photograph by matching the time in the EXIF header with time in the raw HYPACK data and generating a point shapefile showing locations (Photo_locs_gui3.py). The results revealed an offset in the location of the bottom photographs relative to the location of the grab samples, and in some cases, offsets of 10's of meters from the location of the video track.
    In order to QC the times stored in the EXIF header to determine if the position discrepancy was due to an offset in time (incorrect times stored in EXIF headers), the video data collected at each sample location was reviewed to identify the time at which the bottom photograph was taken. The flash of the digital camera as the bottom photograph is taken is clearly visible in the video data. DGPS position and time are displayed on the video data, and were manually recorded at the time of the flash. By comparing the time in the EXIF header to the time in the video data, an offset of 3 minutes 20 seconds was identified The time in the EXIF header was 3 minutes 20 seconds earlier than the time in the video data. This time offset resulted in incorrect positions being associated with each bottom photograph. To rectify this issue, the times in the EXIF headers of the JPEG images were edited to correct the 3 minute 20 second offset.
    The photo_locs_gui3.py was re-run, entering the time offset in the format HHH:MMM:SS (00:03:20). One image, sta8.jpg, did not have navigation recording during the time the photo was taken. Subsequently, the location for that image is based on the closest time available from the navigation file.
    In ArcMap 9.3, the attribute Cruise_ID and System were added to the shapefile.
    Date: 2014 (process 4 of 5)
    Using XTools Pro, version 7.1.0 in ArcMap 9.3.1, the shapefile was exported to a comma-delimited text file: 2005-004-FA_photos.csv. All of the attributes were exported except FID. Data sources used in this process:
    • 2004-004-FA_photos.shp
    Data sources produced in this process:
    • 2004-004-FA_photos.csv
    Date: 06-Apr-2017 (process 5 of 5)
    The online links to the data were updated to reflect the new server hosting the data. Additionally, other small edits could be made to the metadata, such as modifying http to https where appropriate. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
  3. What similar or related data should the user be aware of?
    Argue, Denise M., Kiah, Richard G., Denny, Jane F., Deacon, Jeffrey R., Danforth, William W., Johnston, Craig M., and Smagula, Amy P., 2007, Relation of Lake-Floor Characteristics to the Distribution of Variable Leaf Water-Milfoil in Moultonborough Bay, Lake Winnipesaukee, New Hampshire, 2005: Scientific Investigations Report 2007-5125, U.S. Geological Survey, Reston, Virginia.

    Online Links:

    Blackwood, D., and Parolski, K., 2001, Seabed observation and sampling system: Sea Technology v. 42, no. 2, p. 39-43, Sea Technology, Arlington, Virginia.

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?
    Navigation was acquired with Wide Area Augmentation System (WAAS), which is accurate to + or - 1 to 2 meters, horizontally. Navigation data were acquired with a Communications Systems International (CSI), Inc. LGBX Pro receiver. The CSI LGBX Pro received positions from a WAAS antenna located on the port, aft roof of the R/V Rafael cabin. WAAS positions were recorded within HYPACK (www.hypack.com) navigation software. Offsets between the DGPS antenna and the mini-SEABOSS were not measured. The horizontal position of the mini-SEABOSS during sample collection is assumed to be +/- 10 meters at best, due to a lack of precise positional data at the time of sample recovery.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Forty sample locations were occupied, however bottom photographs were not collected at sample locations 1, 2, 20 and 24 because the dive lights that are used to illuminate the lakefloor in order to take a photograph, failed. We were not able to successfully image the lakefloor with the digital camera at these sample locations. Once new lights were installed, we were able to resume collection of bottom photographs.
  5. How consistent are the relationships among the observations, including topology?
    All bottom photographs were collected in 2005 with the mini-SEABOSS (SEABed Observation and Sampling System, Blackwood and Parolski, 2001) by the U.S. Geological Survey within the Moultonborough Bay, Lake Winnipesaukee, New Hampshire, study area.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None.
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    Jane F. Denny
    U.S. Geological Survey
    384 Woods Hole Road
    Woods Hole, Massachusetts

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
  2. What's the catalog number I need to order this data set? The file 2005-004-FA_photolocs.zip contains the shapefile 2005-004-FA_photos.shp and the other files associated with a shapefile. In addition to the shapefile, the zip file also contains the data in CSV format (2005-004-FA_photos.csv), the browse graphic (2005-004-FA_photolocs.jpg) and the FGDC CSDGM metadata in the following formats: XML, HTML, FAQ and text.
  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 zip file contains data available in Esri shapefile and CSV formats. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcGIS Explorer, capable of displaying the data is available from Esri at www.esri.com.

Who wrote the metadata?

Last modified: 06-Apr-2017
Metadata author:
Jane F. Denny
U.S. Geological Survey
384 Woods Hole Road
Woods Hole, Massachusetts

508-548-8700 x2311 (voice)
508-457-2310 (FAX)
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.36 on Thu Apr 06 14:37:54 2017