Bathymetric LiDAR technology was used to collect riverbed elevation data along the Potomac River. In support of this effort, a bathymetric survey with a boat-mounted acoustic Doppler current profiler (ADCP) was conducted in the study area during October 4-7, 2021. The study area consisted of four verification reaches on the Potomac River including: 1) Williamsport accessed through the Williamsport Park boat ramp below Conococheague Creek and RTE 11 (Williamsport), 2) Big Slackwater above C&O Canal Dam #4 accessed through the Big Slackwater Boat Ramp (Dam4), 3) Four Locks above C&O Canal Dam #5 accessed through the Four Locks Boat Ramp (Dam5), and 4) Little Tonoloway Recreation Area accessed through the Hancock Boat Ramp below RTE 522. Global Navigational Satellite Systems (GNSS) were used to concurrently collect survey grade real-time kinematic (RTK) horizontal and vertical coordinates of the ADCP transducer face. The riverbed elevations were collected using the ADCP with WinRiverII to export for post-processing in Microsoft Excel and RStudio. The GNSS equipment was programmed to continuously collect an observation every 1 to 2 seconds and the ADCP was programmed to continuously collect an observation every 1 second to 2 seconds. The corrected depths from the 4 ADCP beams were averaged and then subtracted from the GNSS derived elevation of the ADCP transducer face to compute the elevation of the riverbed. All spatial data is referenced horizontally to the North American Datum of 1983 (2011) and vertically to the North American Vertical Datum of 1988 (NAVD88). Grid coordinates are projected in Universal Transverse Mercator Zone 18 North and are represented in meter units. This data release consists of four (4) comma-delimited (*.csv) files with fifteen columns each: GNSS_ID, Time_hh_mm_ss, GNSS_Northing_M, GNSS_Easting_M, Computed_Elevation_M, GNSS_Transducer_Elevation_M, Computed_Mean_Depth_M, GNSS_PDOP, GNSS_Vertical Precision_M, GNSS_Satellites, ADCP_Ensemble_ID, ADCP_Temp_C, ADCP_Pitch_Degrees, ADCP_Roll_Degrees, and Type. This data release supersedes a previous version (https://doi.org/10.5066/P9EA0IKM) which contained a constant error of +0.344 meters in the GNSS antenna height reference elevations.

Bathymetric LiDAR technology was used to collect riverbed elevation data along the Potomac River. In support of this effort, a bathymetric survey with a boat-mounted acoustic Doppler current profiler (ADCP) was conducted in the study area during October 4-7, 2021. The study area consisted of four verification reaches on the Potomac River including: 1) Williamsport accessed through the Williamsport Park boat ramp below Conococheague Creek and RTE 11 (Williamsport), 2) Big Slackwater above C&O Canal Dam #4 accessed through the Big Slackwater Boat Ramp (Dam4), 3) Four Locks above C&O Canal Dam #5 accessed through the Four Locks Boat Ramp (Dam5), and 4) Little Tonoloway Recreation Area accessed through the Hancock Boat Ramp below RTE 522. Global Navigational Satellite Systems (GNSS) were used to concurrently collect survey grade real-time kinematic (RTK) horizontal and vertical coordinates of the ADCP transducer face. The riverbed elevations were collected using the ADCP with WinRiverII to export for post-processing in Microsoft Excel and RStudio. The GNSS equipment was programmed to continuously collect an observation every 1 to 2 seconds and the ADCP was programmed to continuously collect an observation every 1 second to 2 seconds. The corrected depths from the 4 ADCP beams were averaged and then subtracted from the GNSS derived elevation of the ADCP transducer face to compute the elevation of the riverbed. All spatial data is referenced horizontally to the North American Datum of 1983 (2011) and vertically to the North American Vertical Datum of 1988 (NAVD88). Grid coordinates are projected in Universal Transverse Mercator Zone 18 North and are represented in meter units. This data release consists of four (4) comma-delimited (*.csv) files with fifteen columns each: GNSS_ID, Time_hh_mm_ss, GNSS_Northing_M, GNSS_Easting_M, Computed_Elevation_M, GNSS_Transducer_Elevation_M, Computed_Mean_Depth_M, GNSS_PDOP, GNSS_Vertical Precision_M, GNSS_Satellites, ADCP_Ensemble_ID, ADCP_Temp_C, ADCP_Pitch_Degrees, ADCP_Roll_Degrees, and Type. This data release supersedes a previous version (https://doi.org/10.5066/P9EA0IKM) which contained a constant error of +0.344 meters in the GNSS antenna height reference elevations.

Bathymetric LiDAR technology was used to collect riverbed elevation data along the Potomac River. In support of this effort, a bathymetric survey with a boat-mounted acoustic Doppler current profiler (ADCP) was conducted in the study area during October 4-7, 2021. The study area consisted of four verification reaches on the Potomac River including: 1) Williamsport accessed through the Williamsport Park boat ramp below Conococheague Creek and RTE 11 (Williamsport), 2) Big Slackwater above C&O Canal Dam #4 accessed through the Big Slackwater Boat Ramp (Dam4), 3) Four Locks above C&O Canal Dam #5 accessed through the Four Locks Boat Ramp (Dam5), and 4) Little Tonoloway Recreation Area accessed through the Hancock Boat Ramp below RTE 522. Global Navigational Satellite Systems (GNSS) were used to concurrently collect survey grade real-time kinematic (RTK) horizontal and vertical coordinates of the ADCP transducer face. The riverbed elevations were collected using the ADCP with WinRiverII to export for post-processing in Microsoft Excel and RStudio. The GNSS equipment was programmed to continuously collect an observation every 1 to 2 seconds and the ADCP was programmed to continuously collect an observation every 1 second to 2 seconds. The corrected depths from the 4 ADCP beams were averaged and then subtracted from the GNSS derived elevation of the ADCP transducer face to compute the elevation of the riverbed. All spatial data is referenced horizontally to the North American Datum of 1983 (2011) and vertically to the North American Vertical Datum of 1988 (NAVD88). Grid coordinates are projected in Universal Transverse Mercator Zone 18 North and are represented in meter units. This data release consists of four (4) comma-delimited (*.csv) files with fifteen columns each: GNSS_ID, Time_hh_mm_ss, GNSS_Northing_M, GNSS_Easting_M, Computed_Elevation_M, GNSS_Transducer_Elevation_M, Computed_Mean_Depth_M, GNSS_PDOP, GNSS_Vertical Precision_M, GNSS_Satellites, ADCP_Ensemble_ID, ADCP_Temp_C, ADCP_Pitch_Degrees, ADCP_Roll_Degrees, and Type. This data release supersedes a previous version (https://doi.org/10.5066/P9EA0IKM) which contained a constant error of +0.344 meters in the GNSS antenna height reference elevations.

Bathymetric LiDAR technology was used to collect riverbed elevation data along the Potomac River. In support of this effort, a bathymetric survey with a boat-mounted acoustic Doppler current profiler (ADCP) was conducted in the study area during October 4-7, 2021. The study area consisted of four verification reaches on the Potomac River including: 1) Williamsport accessed through the Williamsport Park boat ramp below Conococheague Creek and RTE 11 (Williamsport), 2) Big Slackwater above C&O Canal Dam #4 accessed through the Big Slackwater Boat Ramp (Dam4), 3) Four Locks above C&O Canal Dam #5 accessed through the Four Locks Boat Ramp (Dam5), and 4) Little Tonoloway Recreation Area accessed through the Hancock Boat Ramp below RTE 522. Global Navigational Satellite Systems (GNSS) were used to concurrently collect survey grade real-time kinematic (RTK) horizontal and vertical coordinates of the ADCP transducer face. The riverbed elevations were collected using the ADCP with WinRiverII to export for post-processing in Microsoft Excel and RStudio. The GNSS equipment was programmed to continuously collect an observation every 1 to 2 seconds and the ADCP was programmed to continuously collect an observation every 1 second to 2 seconds. The corrected depths from the 4 ADCP beams were averaged and then subtracted from the GNSS derived elevation of the ADCP transducer face to compute the elevation of the riverbed. All spatial data is referenced horizontally to the North American Datum of 1983 (2011) and vertically to the North American Vertical Datum of 1988 (NAVD88). Grid coordinates are projected in Universal Transverse Mercator Zone 18 North and are represented in meter units. This data release consists of four (4) comma-delimited (*.csv) files with fifteen columns each: GNSS_ID, Time_hh_mm_ss, GNSS_Northing_M, GNSS_Easting_M, Computed_Elevation_M, GNSS_Transducer_Elevation_M, Computed_Mean_Depth_M, GNSS_PDOP, GNSS_Vertical Precision_M, GNSS_Satellites, ADCP_Ensemble_ID, ADCP_Temp_C, ADCP_Pitch_Degrees, ADCP_Roll_Degrees, and Type.

Bathymetric LiDAR technology was used to collect riverbed elevation data along the Potomac River. In support of this effort, a bathymetric survey with a boat-mounted acoustic Doppler current profiler (ADCP) was conducted in the study area during October 4-7, 2021. The study area consisted of four verification reaches on the Potomac River including: 1) Williamsport accessed through the Williamsport Park boat ramp below Conococheague Creek and RTE 11 (Williamsport), 2) Big Slackwater above C&O Canal Dam #4 accessed through the Big Slackwater Boat Ramp (Dam4), 3) Four Locks above C&O Canal Dam #5 accessed through the Four Locks Boat Ramp (Dam5), and 4) Little Tonoloway Recreation Area accessed through the Hancock Boat Ramp below RTE 522. Global Navigational Satellite Systems (GNSS) were used to concurrently collect survey grade real-time kinematic (RTK) horizontal and vertical coordinates of the ADCP transducer face. The riverbed elevations were collected using the ADCP with WinRiverII to export for post-processing in Microsoft Excel and RStudio. The GNSS equipment was programmed to continuously collect an observation every 1 to 2 seconds and the ADCP was programmed to continuously collect an observation every 1 second to 2 seconds. The corrected depths from the 4 ADCP beams were averaged and then subtracted from the GNSS derived elevation of the ADCP transducer face to compute the elevation of the riverbed. All spatial data is referenced horizontally to the North American Datum of 1983 (2011) and vertically to the North American Vertical Datum of 1988 (NAVD88). Grid coordinates are projected in Universal Transverse Mercator Zone 18 North and are represented in meter units. This data release consists of four (4) comma-delimited (*.csv) files with fifteen columns each: GNSS_ID, Time_hh_mm_ss, GNSS_Northing_M, GNSS_Easting_M, Computed_Elevation_M, GNSS_Transducer_Elevation_M, Computed_Mean_Depth_M, GNSS_PDOP, GNSS_Vertical Precision_M, GNSS_Satellites, ADCP_Ensemble_ID, ADCP_Temp_C, ADCP_Pitch_Degrees, ADCP_Roll_Degrees, and Type.

Bathymetric data were collected using a boat-mounted Wide Area Augmentation System (WAAS), a type of differential global positioning system, echo depth-sounding equipment, and computer software. Data were exported into a geographic information system and converted into a point layer. These data points were used to create a triangulated irregular network (TIN) from which 2-foot contours were created. The contours were then clipped with a manually digitized outline of the reservoir shoreline and edited for errors. The resulting data was used for mapping purposes and for calculating area and volume statistics.

The Old Erie Canal has undergone sedimentation and aquatic growth that have restricted flow and diminished the aesthetic quality of the canal during the nearly 200 years since its construction. During 2018–2019, the U.S. Geological Survey (USGS) in cooperation with the Madison County Planning Department and the New York State Canal Corporation conducted a study of the Old Erie Canal between the Town of DeWitt, New York, and its junction with the current Erie Canal of the New York State Canal System near Rome, N.Y. The study comprised bathymetric, velocity, and water-quality surveys and documentation of the canal infrastructure. The USGS established benchmarks and staff gages along the 30.8 miles of the canal study area to reference the water-surface level in the canal to the North American Vertical Datum of 1988 (NAVD 88). Water-quality data (dissolved oxygen, water temperature, specific conductance, pH, and turbidity) were collected concurrently with the bathymetric survey (spring 2018) to characterize changes in water quality along the length of the canal. The canal infrastructure was documented to provide a baseline assessment. This dataset contains a point shapefile representing the Acoustic Doppler Current Profiler (ADCP) observations made during the 2018 survey, and includes measurements of bathymetry, water level elevation, and water column depth along transects of Old Erie Canal.

These data are bathymetry (river bottom elevation) in XYZ format (Easting, Northing, Elevation), generated from the July 24–25, 2023, and July 31, 2023, bathymetric survey of the Green River near Brownsville, Kentucky, from approximately 1.5 miles downstream from the Brownsville boat ramp to approximately 0.8 mile upstream from the former Green River Lock and Dam #6 site (3.8 miles total reach length). Hydrographic data were collected using an acoustic Doppler current profiler (ADCP) with an integrated global navigation satellite system (GNSS) smart antenna. The ADCP and GNSS antenna were mounted on a marine survey vessel, and data were collected as the survey vessel traversed the river along planned survey lines. A total of 207 survey lines were oriented approximately perpendicular to the primary flow direction at variable spacing (generally spaced 100 feet apart but at a 500-foot spacing along the downstream portion of the reach and at 10- to 50-foot spacing in two areas of interest). Data collection software integrated and stored the depth and position data from the ADCP and GNSS antenna in real time. Water-surface elevations were measured approximately every 500 feet throughout the survey area with a survey-grade integrated GNSS system with real-time kinematic (RTK) observations to convert measured bathymetric depths to elevations referenced to the North American Vertical Datum of 1988 (NAVD 88). RTK observations were made using the Kentucky Continually Operating Reference System (KYCORS) network operated by the Kentucky Transportation Cabinet. Data processing required computer software to extract the bathymetric data from the raw data files and to compile and map the information. The final comma-delimited file contains columns of Easting and Northing in feet North American Datum of 1983 (NAD83) Kentucky State Plane Single Zone (FIPS code 1600), and Elevation in feet NAVD 88.

This portion of the USGS data release presents bathymetry data collected during surveys performed in the Columbia River littoral cell, Washington and Oregon in 2015 (USGS Field Activity Number 2015-647-FA). Bathymetry data were collected using four personal watercraft (PWCs) equipped with single-beam sonar systems and global navigation satellite system (GNSS) receivers. The sonar systems consisted of an Odom Echotrac CV-100 single-beam echosounder and 200 kHz transducer with a 9 degree beam angle. Raw acoustic backscatter returns were digitized by the echosounder with a vertical resolution of 1.25 cm. Depths from the echosounders were computed using sound velocity profiles measured using a YSI CastAway CTD during the survey. Positioning of the survey vessels was determined at 5 to 10 Hz using Trimble R7 GNSS receivers. Output from the GNSS receivers and sonar systems were combined in real time on the PWC by a computer running HYPACK hydrographic survey software. Navigation information was displayed on a video monitor, allowing PWC operators to navigate along survey lines at speeds of 2 to 3 m/s. Survey-grade positions of the PWCs were achieved with a single-base station and differential post-processing. Positioning data from the GNSS receivers were post-processed using Waypoint Grafnav to apply differential corrections from a GNSS base station with known horizontal and vertical coordinates relative to the North American Datum of 1983. Orthometric elevations relative to the NAVD88 vertical datum were computed using National Geodetic Survey Geoid12a offsets. Bathymetric data were merged with post-processed positioning data and spurious soundings were removed using a custom Graphical User Interface (GUI) programmed with the computer program MATLAB. The average estimated vertical uncertainty of the bathymetric measurements is 10 cm. The final point data from the PWCs are provided in a comma-separated text file and are projected in cartesian coordinates using the Washington State Plane South, meters coordinate system.

This portion of the USGS data release presents bathymetry data collected during surveys performed in the Columbia River littoral cell, Washington and Oregon in 2016 (USGS Field Activity Number 2016-663-FA). Bathymetry data were collected using four personal watercraft (PWCs) equipped with single-beam sonar systems and global navigation satellite system (GNSS) receivers. The sonar systems consisted of an Odom Echotrac CV-100 single-beam echosounder and 200 kHz transducer with a 9 degree beam angle. Raw acoustic backscatter returns were digitized by the echosounder with a vertical resolution of 1.25 cm. Depths from the echosounders were computed using sound velocity profiles measured using a YSI CastAway CTD during the survey. Positioning of the survey vessels was determined at 5 to 10 Hz using Trimble R7 GNSS receivers. Output from the GNSS receivers and sonar systems were combined in real time on the PWC by a computer running HYPACK hydrographic survey software. Navigation information was displayed on a video monitor, allowing PWC operators to navigate along survey lines at speeds of 2 to 3 m/s. Survey-grade positions of the PWCs were achieved with a single-base station and differential post-processing. Positioning data from the GNSS receivers were post-processed using Waypoint Grafnav to apply differential corrections from a GNSS base station with known horizontal and vertical coordinates relative to the North American Datum of 1983. Orthometric elevations relative to the NAVD88 vertical datum were computed using National Geodetic Survey Geoid12a offsets. Bathymetric data were merged with post-processed positioning data and spurious soundings were removed using a custom Graphical User Interface (GUI) programmed with the computer program MATLAB. The average estimated vertical uncertainty of the bathymetric measurements is 10 cm. The final point data from the PWCs are provided in a comma-separated text file and are projected in cartesian coordinates using the Washington State Plane South, meters coordinate system.