Richard J. Huizinga, U.S. Geological Survey, Hydrologist Benjamin C. Rivers, U.S. Geological Survey, Physical Scientist 20230316 Vector Digital Data Set (Point) U.S. Geological Survey ScienceBase data release version 1.0 Denver, CO U.S. Geological Survey - ScienceBase https://doi.org/10.5066/P9BV1H0S Richard J. Huizinga Benjamin C. Rivers Joseph M. Richards Garett J. Waite 2023 publication n/a US Geological Survey https://doi.org/10.3133/sir20235046 Water supply lakes are the primary source of water for many communities in northern and western Missouri. Therefore, accurate and up-to-date estimates of lake capacity are important for managing and predicting adequate water supply. Many of the water supply lakes in Missouri were previously surveyed by the U.S. Geological Survey in the early 2000s (Richards, 2013) and in 2013 (Huizinga, 2014); however, years of potential sedimentation may have resulted in reduced water storage capacity. Periodic bathymetric surveys are useful to update the area/capacity table and to determine changes in the bathymetric surface. Number 41 Lake (locally known as Milan Golf Course Lake) is a water supply lake used by the city of Milan in north-central Missouri. The surface area of Number 41 Lake is about 49 acres at the full pool level of the primary spillway (865.8 feet above the North American Vertical Datum of 1988). No previous bathymetric survey has been completed at this lake. In July 2020, the U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources and in collaboration with the City of Milan, completed a bathymetric survey of Number 41 Lake using a multibeam echosounder. The water-surface elevation during the survey was about 865.7 feet. The echosounder data can be combined with light detection and ranging (lidar) data to prepare a bathymetric map and a surface area and capacity table for the lake. The gridded bathymetric point data (MilanGolfCourseLake2020_bathy_pts.zip) were computed on a 0.82-foot (0.25-meter) grid using the Combined Uncertainty and Bathymetry Estimator (CUBE) method, which is used as the source of points to create the bathymetric surface. Bathymetric quality-assurance data (MilanGolfCourseLake2020_QA_raw.zip) were collected to evaluate the vertical accuracy of the gridded bathymetric point data. Each of these two zip files contains a shapefile with an attribute table. Attribute/column labels of each table are described in the "Entity and attribute" section of the metadata file. References Cited: Huizinga, R.J., 2014, Bathymetric surveys and area/capacity tables of water-supply reservoirs for the city of Cameron, Missouri, July 2013: U.S. Geological Survey Open-File Report 2014–1005, 15 p., https://doi.org/10.3133/ofr20141005. Richards, J.M., 2013, Bathymetric surveys of selected lakes in Missouri—2000–2008: U.S. Geological Survey Open-File Report 2013–1101, 9 p. with appendix, https://pubs.usgs.gov/of/2013/1101. The Missouri Department of Natural Resources (MoDNR) Water Resource Center and Missouri's Safe Drinking Water Program has the responsibility of assisting state residents in assuring an adequate and safe water supply. As a result, a water supply study has been ongoing to ensure availability of water information for effective decision-making by communities and MoDNR program managers. One of the benefits of the study is to determine and allocate existing water supplies, with the scope of the study to address surface-water supplies for cities and communities that are expected to experience water shortages during an extended drought. Surface-water supplies consist of lakes and streams, and in many cases, combinations of both. Water-supply lake bathymetric surveys are integral to the water availability assessments during potential water shortages. 20200706 Date of survey Complete As needed -93.1047 -93.0939 40.1993 40.1938 None U.S. Geological Survey USGS Missouri Bathymetry Multibeam multibeam sonar USGS Thesaurus bathymetry Data Categories for Marine Planning Bathymetry and Elevation USGS Metadata Identifier USGS:6230d038d34ec9f19eeaf53b Geographic Names Information System (GNIS) Milan Number 41 Lake Missouri Sullivan County None Milan Golf Course Lake None None Richard J. Huizinga USGS Central Midwest Water Science Center mailing and physical

1400 Independence Road, MS 100

Rolla MO 65401 USA (573) 308-3570 huizinga@usgs.gov Please recognize the U.S. Geological Survey (USGS) and the Missouri Department of Natural Resources for use of these data. Environment as of Metadata Creation: Microsoft Windows 10 Enterprise, Version 20H2; HYPACK Version 21.2.6.0; POSPac MMS Version 8.6.7810.21570; Global Mapper v22.1; Esri ArcGIS 10.8.1 (Build 14362) Joseph M. Richards 2013 publication U.S. Geological Survey Open File Report 2013-1101 https://pubs.usgs.gov/of/2013/1101 Joseph M. Richards Richard J. Huizinga Jarrett T. Ellis 2019 publication U.S. Geological Survey Scientific Investigations Map 3431 https://doi.org/10.3133/sim3431 Richard J. Huizinga 2014 publication U.S. Geological Survey Open File Report 2014-1005 https://doi.org/10.3133/ofr20141005 Mark R. Byrnes Jessica L. Baker Feng Li 2002 publication Vicksburg, Miss. U.S. Army Corps of Engineers ERDC/CHL CHETN–IV–50 https://apps.dtic.mil/sti/pdfs/ADA588888.pdf HYPACK, Inc. 202101 publication Middletown, Conn. HYPACK, Inc. Applanix Corporation 201906 publication Ontario, Canada Applanix Corporation PUBS-MAN-001768 U.S. Army Corps of Engineers 2013 publication U.S. Army Corps of Engineers Engineering Manual EM 1110-2-1003 11 chapters plus appendixes and glossary https://www.publications.usace.army.mil/Portals/76/Publications/EngineerManuals/EM_1110-2-1003.pdf?ver=gDGVUj_0XR2sXHiIpQZv2Q%3d%3d The errors associated with the collection of bathymetric data can be classified as systematic or random. Systematic errors are those that can be measured or modeled through calibration (Byrnes and others, 2002). Random errors are a result of the limitations of the measuring device and an inability to perfectly model the systematic errors. The errors reported are related to uncertainty of the bathymetric data as estimated using the Combined Uncertainty and Bathymetry Estimator (CUBE) method as implemented in the HYPACK/HYSWEEP software. The multibeam echosounder mapping system (MBMS) requires a rigorous calibration procedure before accurate datasets can be generated. All instrumentation must first be surveyed, and their relative positions (lever arms) must be resolved with respect to the origin point of the inertial navigation system (INS). A patch test procedure is then performed in order to determine the angular differences (roll, pitch, and heading) between the INS and the multibeam echosounder (MBES) transducer head. This process involves surveying over various bathymetric features in the same or opposing directions, from which the potential differences in the angular offsets can be identified and quantified. Field procedures described in multiple lake bathymetry reports (see for example, Richards and others, 2019) were followed during the collection of bathymetric data. For the MBMS, the principal quality-assurance measures were assessed in real time during the survey. The MBMS operator continuously assessed the quality of the collected data during the survey by making visual observations of across-track swaths (such as convex, concave, or skewed bed returns in flat, smooth bottoms), noting data quality flags and alarms from the MBES and the INS, and noting comparisons between adjacent overlapping swaths. In addition to the real-time quality-assurance assessments during the survey, beam-angle checks and a suite of patch tests were executed to ensure quality data were acquired from the MBMS. A beam-angle check is used to determine the accuracy of the depth readings obtained by the outer beams (greater than 25 degrees from nadir [vertical]) of the MBES, which may change with time as a result of inaccurate sound velocities, physical configuration changes, and overall depth being surveyed. The HYPACK/HYSWEEP software has a utility that develops a statistical assessment of the quality of the outer beams compared to a reference surface (HYPACK, Inc., 2021). A beam-angle check was done at Mozingo Lake near Maryville on June 23, 2020, and included a sound velocity cast to document and quantify any stratification in the water column near the reference surface. The results of this beam-angle check were within the recommended performance standards used by the U.S. Army Corps of Engineers for hydrographic surveys for all of the representative angles (U.S. Army Corps of Engineers, 2013), permitting the use of the entire sonar swath with confidence. Raw navigation and motion-sensing data were recorded by the INS controller, beginning at least 5 minutes before any bathymetric or topographic data were collected, and continuing at least 5 minutes after the last data were collected. Bathymetric data were recorded in HYPACK/HYSWEEP as a survey file, which records all bathymetric survey line data, configuration information, and quality assurance and quality control results. Each survey line was recorded to a separate file and began when the boat was positioned at the end of a planned line. The boat operator would navigate along the planned survey line to the opposite end, avoiding sharp changes in speed or direction. At the opposite end of a survey line, data recording was stopped and the boat would move to the next planned survey line. Occasionally, gaps would appear in the data due to changes in bed topography, and attempts were made to adjust the survey to cover these gaps. The POSPac MMS software package uses differential correction algorithms to compute a smoothed best estimate of trajectory (SBET) file. Errors associated with the SBET file would be applicable to the horizontal positional accuracy of the bathymetric data. The horizontal accuracy of the postprocessed POSPac MMS files has a minimum and maximum root mean square (RMS) error of 0.9 and 1.4 centimeters, respectively. Stated accuracies are based on peak-to-peak errors. The POSPac MMS software package uses differential correction algorithms to compute a smoothed best estimate of trajectory (SBET) file. Errors associated with the SBET file would be applicable to the vertical positional accuracy of the bathymetric quality assurance data. The vertical accuracy of the postprocessed POSPac MMS files has a minimum and maximum root mean square (RMS) error of 3.6 and 4.5 centimeters, respectively. Stated accuracies are based on peak-to-peak errors. Uncertainty in the bathymetric survey was estimated using the Combined Uncertainty and Bathymetry Estimator (CUBE) method, as implemented in the HYPACK/HYSWEEP software. The CUBE method allows all random system component uncertainties and resolution effects to be combined and propagated through the data processing steps, which provides a robust estimate of the spatial distribution of possible uncertainty within each cell of the survey area. Thus, the reported uncertainty of a point is a measure of the accuracy to be expected for such a point when all relevant error sources in a given cell are taken into account. The largest uncertainty in this survey was about 4.95 feet (1.51 meter); however, most of the uncertainty values (more than 85.6 percent) were less than 0.25 foot (7.6 centimeters). Larger uncertainty values occur near moderate- to high-relief features (banks and rock outcrops). Occasionally, these larger uncertainty values also occurred in the outermost beam parts of the multibeam swath in the overlap with an adjacent swath, particularly when the MBES head was electronically tilted for the survey lines along the banks or in coves. The gridded final data were compared to ungridded, quality-assurance data collected at 1 transect oriented perpendicular to the main bathymetric survey (contained in MilanGolfCourseLake2020_QA_raw.zip) if they were within a tolerance of 0.16 foot (0.05 meter) of a gridded bathymetric point. Only the quality-assurance point nearest the gridded bathymetric point was used in this comparison. There were 16,433 comparisons between the gridded bathymetric data and the bathymetric quality-assurance data, and the gridded bathymetric data tested at a 0.21 foot (0.06 meter) vertical accuracy at the 95-percent confidence level. While the point to point comparison is not an exact measure of bathymetric survey repeatability, the vertical accuracy, as calculated here, represents the degradation of vertical accuracy introduced when converting the raw MBES data to a 0.82 foot (0.25 meter) set of gridded data using the CUBE method for this survey at this lake. Collection of bathymetric data in the survey area used a marine-based mobile mapping unit that operates with several components: a multibeam echosounder (MBES) unit, an inertial navigation system (INS), and a data acquisition computer. The MBES system used was the NORBIT iWBMSh, operated at a frequency of 400 kilohertz. The iWMBSh is similar in operation to the MBES systems used in other previous studies in Missouri. This MBES system has a curved receiver array that enables bathymetric data to be collected throughout a swath range of 210 degrees. Optimum data usually are collected in a swath of less than 160 degrees (80 degrees on each side of nadir, or straight down below the MBES); nevertheless, the swath can be electronically rotated to either side of nadir, enabling data to be captured along sloping banks up to a depth just below the water surface. The INS was the Applanix OceanMaster, which consists of two global navigation satellite system (GNSS) receivers, an inertial measurement unit (IMU), and a controller/processor. The INS locates the MBES in three-dimensional space, and measures the heave, pitch, roll, and heading of the vessel (and, thereby, the MBES) to accurately position the data received by the MBES. Bathymetric data were collected using the MBES unit in longitudinal transects to provide complete coverage of the lake. The MBES was electronically tilted in some areas to improve data collection along the shoreline, in coves, and in areas that are shallower than about 2.0 meters deep (the practical limit of reasonable and safe data collection with the MBES). Bathymetric quality-assurance data were collected using the MBES unit at 1 transect oriented perpendicular to the longitudinal transects of the bathymetric survey data. The swath was limited to the central 90 degrees, 45 degrees on each side of nadir to limit erroneous soundings. 20200706 The logged navigation and motion-sensing information from the survey was postprocessed using the POSPac Mobile Mapping Suite (MMS) software, which provides tools to identify and compensate for sensor and environmental errors, and computes an optimally blended navigation solution from the GNSS and IMU raw data. The blended navigation solution (called a smoothed best estimate of trajectory or SBET file), generated by postprocessing the navigation data was applied to the bathymetric survey to minimize the effects of GNSS outages, and to properly georeference the survey data. 20200825 The MBES bathymetric dataset was processed using filters in the HYPACK/HYSWEEP software (http://www.hypack.com) to remove data spikes or erroneous points. The filtered multibeam data were gridded to 0.82 feet (0.25 meter) using the elevation values computed from the Combined Uncertainty and Bathymetry Estimator (CUBE) method, which provides an estimate of the bathymetric elevation and the uncertainty at each gridded location. Further quality assurance evaluation of the gridded CUBE data included removal of data points with extremely high uncertainty values, removal of data points that plotted outside of the shoreline that was topographically derived from lidar data, and removal of data points that were higher in elevation than the minimum lake surface elevation during surveying. The resulting bathymetric dataset contained approximately 2.4 million points. The bathymetric quality assurance dataset was minimally processed using filters in the HYPACK/HYSWEEP software (http://www.hypack.com) to remove data spikes or erroneous points and output at the full resolution of the data. The resulting bathymetric quality-assurance data set contained approximately 681 thousand points. 20210623 Points used to create a bathymetric surface (mapping points) were selected from the 2.4-million-point dataset such that the minimum distance between any two points would be no less than 1.64 feet (0.5 meter). Points used to evaluate the vertical accuracy of the bathymetric surface relative to the point elevations (surface quality-assurance points) were randomly chosen from the 2.4-million-point dataset. Selection of the surface quality-assurance points purposely avoided any mapping points used to make the bathymetric surface. Mapping points and surface quality-assurance points are identified by attributes in the dataset. The data are provided in the Environmental Systems Research Institute (ESRI) shapefile format consisting of a group of files that has been compressed into a zip archive that is named MilanGolfCourseLake2020_bathy_pts.zip. 20220315 Universal Transverse Mercator 15 0.9996 -93.0 0.0 500000.0 0.0 coordinate pair 0.01 0.01 meters North American Datum of 1983 GRS 1980 6378137.0 298.257222101 North American Vertical Datum of 1988 0.01 feet Explicit elevation coordinate included with horizontal coordinates MilanGolfCourseLake2020_bathy_pts.shp Attribute table Table containing attribute information with the data set. Producer Defined X X coordinate of the data point, in meters, in the Universal Transverse Mercator projection, Zone 15, North American Datum of 1983 Producer Defined 491090.12 491856.37 meters Y Y coordinate of the data point, in meters, in the Universal Transverse Mercator projection, Zone 15, North American Datum of 1983 Producer Defined 4449336.62 4449854.37 meters Z Elevation value at the location of the data point, in feet, referenced to the North American Vertical Datum of 1988 using the geoid model GEOID18 Producer Defined 841.59 863.93 feet CUBE_Uncer Uncertainty value at the location of the data point, in feet, using the Combined Uncertainty and Bathymetry Estimator (CUBE) method as implemented in the HYPACK/HYSWEEP software Producer Defined 0.00 4.95 feet Map Integer flag indicating if the data point was used to create the bathymetric surface from which contours and the area/capacity table were generated Producer Defined 1 point used Producer defined 0 point not used Producer defined QA Integer flag indicating if the data point was used to evaluate the vertical accuracy of the bathymetric surface Producer Defined 1 point used Producer defined 0 point not used Producer defined Source Text descriptor of source of data. Producer Defined MB Multibeam data Producer defined MilanGolfCourseLake2020_QA_raw.shp Attribute table Table containing attribute information associated with the data set. Producer defined X X coordinate of the data point, in meters, in the Universal Transverse Mercator projection, Zone 15, North American Datum of 1983 Producer defined 491564.25 491427.64 meters Y Y coordinate of the data point, in meters, in the Universal Transverse Mercator projection, Zone 15, North American Datum of 1983 Producer defined 4449535.30 4449700.02 meters Zxcheck Elevation value at the location of the data point, in feet, referenced to the North American Vertical Datum of 1988 using the geoid model GEOID18 Producer defined 847.43 855.34 feet QA Flag indicating if the data point was used to evaluate the vertical accuracy of the gridded bathymetric data Producer defined 0 point not used Producer defined 1 point used Producer defined The entity and attribute information provided here describes the tabular data associated with the dataset. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the dataset. The entity and attribute information was generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information. U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 USA 1-888-275-8747 sciencebase@usgs.gov 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, 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 names is for descriptive purposes only and does not imply endorsement by the U.S. Government. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners. Vector Digital Data (Point) https://www.sciencebase.gov/catalog/file/get/6230d038d34ec9f19eeaf53b?name=MilanGolfCourseLake2020_bathy_pts.zip https://www.sciencebase.gov/catalog/file/get/6230d038d34ec9f19eeaf53b?name=MilanGolfCourseLake2020_QA_raw.zip None. No fees are applicable for obtaining the dataset. 20230601 Richard J. Huizinga U.S. Geological Survey - Central Midwest Water Science Center Hydrologist mailing address

1400 Independence Rd, MS 100

Rolla MO 65401 USA (573) 308-3570 huizinga@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 local time