Alexander G. Snyder Andrew W. Stevens Emily Carlson Jessica R. Lacy 2016 comma-delimited text and shapefile data release DOI:10.5066/F7RX9954 Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/F7RX9954 https://www.sciencebase.gov/catalog/item/56671eb2e4b06a3ea36c8bf2 Alexander G. Snyder Andrew W. Stevens Emily Carlson Jessica R. Lacy 2016 data release DOI:10.5066/F7RX9954 Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/F7RX9954 Bathymetric data were collected by the U.S. Geological Survey (USGS) in 2015 for Little Holland Tract in the Sacramento-San Joaquin River Delta, California. The data were collected using a personal watercraft (PWC) platform that consisted of Trimble R7 Global Navigation Satellite System (GNSS) receivers with Zephyr 2 antennas, combined with Odom Echotrac CV-100 single-beam echosounders and 200 kHz transducers. Data was post-processed to remove spurious data points. Raw depths were converted to ellipsoid elevations in the data acquisition software. Orthometric elevations relative to NAVD88 were computed using National Geodetic Survey Geoid12a offsets, and the final data were projected in Cartesian coordinates using the UTM Zone 10 North (meters) (NAD83[2011]) coordinate system. The mean estimated vertical uncertainty of the 2015 USGS PWC survey is 6.1 cm. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify bathymetric features. Additional information about the field activities from which these data were derived are available online at: http://cmgds.marine.usgs.gov/fan_info.php?fan=2015-642-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology. 20150608 20150619 ground condition Complete None planned -121.667629767 -121.648939185 38.350195381 38.28554843 USGS Metadata Identifier USGS:56671eb2e4b06a3ea36c8bf2 USGS Thesaurus bathymetry bathymetry measurement GPS measurement ISO 19115 Topic Category elevation Data Categories for Marine Planning Bathymetry and Elevation Marine Realms Information Bank (MRIB) keywords single-beam echo sounder Global Positioning System (GPS) observations Global Change Master Directory (GCMD) Water Depth GPS (Global Positioning System) Echo Sounders Geographic Names Information System (GNIS) Sacramento-San Joaquin Delta Little Holland Tract Yolo County Solano County Liberty Island Sacramento River Deep Water Ship Channel none USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigational purposes. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060-5792 US 831-427-4747 pcmsc_data@usgs.gov Environment as of Metadata Creation: Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.2.2 (Build 3552) Service Pack N/A (Build N/A) The uncertainty associated with positioning of the survey platforms was estimated by computing the standard deviations of the GNSS rover positions relative to the base station using Waypoint Grafnav (version 8.50). Depths measured using sonar are subject to additional sources of uncertainty including fluctuations in the speed of sound and from the pitch and roll of the survey vessels. Given the relatively calm water surface and low range of water depth present in this survey, we estimate depth sounding uncertainty to be 1 percent of the water depth. Data fall within expected ranges, efforts were made during digital elevation modeling to best represent reality. Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. The uncertainty associated with positioning of the survey platforms was estimated by computing the standard deviations of the GNSS rover positions relative to the base station using Waypoint Grafnav (version 5.0). Based on these calculations, the mean horizontal accuracy of GNSS positions at the 95 percent confidence interval (1.96 times the standard deviations assuming a normal distribution) is 3.5 cm. The uncertainty associated with positioning of the survey platforms was estimated by computing the standard deviations of the GNSS rover positions relative to the base station using Waypoint Grafnav (version 5.0). Based on these calculations, the mean vertical accuracy of GNSS positions at the 95 percent confidence interval (1.96 times the standard deviations assuming a normal distribution) were calculated. Depths measured using sonar are subject to additional sources of uncertainty including fluctuations in the speed of sound and from the pitch and roll of the survey vessels. Given the relatively calm water surface and low range of water depth present in this survey, we estimate depth sounding uncertainty to be 1 percent of the water depth. The mean estimated vertical uncertainty is 6.1 cm. Bathymetric data were collected primarily using two personal watercraft (PWC), equipped with single-beam echosounders and dual-frequency global navigation satellite systems (GNSS) receivers. The sonar systems consisted of Odom Echotrac CV-100 single-beam echosounders and 200 kHz transducers with 9-degree beam angles that digitize depth returns at a resolution of 1.25 cm. Positioning of the survey vessels was determined at 10-Hz using Trimble R7 GNSS receivers with Zephyr 2 antennas operating in autonomous mode. Output from the GNSS and sonar systems were combined in real time on the PWC by a computer running HYPACK (version 13.0.0.6) hydrographic survey software. Navigation and data quality information were displayed on a video monitor, allowing PWC operators to navigate along survey lines at speeds of 2 to 3 meters per second. Depths from the echosounders were computed using a sound velocity of 1488.80 meters per second, measured during the survey with a YSI Castaway CTD. Digitized depths were compared to the raw acoustic backscatter signal using a Graphical User Interface (GUI) programmed using the computer program Matlab to ensure the accuracy of depths produced by the echosounder. In areas where the automated echosounder signal processing failed (typical in very shallow regions), the GUI was used to digitize the bottom by hand. Once the raw depths were adjusted, a running mean with a window length of 5 points (approximately 1 m distance) was used to remove high-frequency vertical fluctuations, such as those caused by pitch and roll of the survey vessels. 20150608 Data collection using same methods as above. 20150619 Survey-grade positioning of the PWCs were obtained using a post-processed kinematic (PPK) methodology, whereby Waypoint Grafnav (version 8.50) was used to make differential corrections referenced to a single base station described in the previous section. The post-processed positioning data were then merged with sonar depths to determine the elevation of the bed. Orthometric elevations relative to NAVD88 were computed using the National Geodetic Survey Geoid12a, and the final data were projected in Cartesian coordinates using the UTM Zone 10 North (meters) coordinate system. 201506 All data were compiled into a single shapefile. 20151117 Edits were made as needed to bring the metadata up to current PCMSC standards including standardizing doi# links, correcting typos, adding disclaimers, and refining keywords. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. No data were changed. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version. 2020710 Susan A Cochran U.S. Geological Survey, Pacific Coastal and Marine Science Center mailing and physical

2885 Mission St.

Santa Cruz CA 95060 United States 831-460-7545 scochran@usgs.gov Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 20201019 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Point Entity point 652120 Universal Transverse Mercator 10 0.9996 -123.0 0.0 500000.0 0.0 coordinate pair 0.6096 0.6096 Meter D_North_American_1983 GRS_1980 6378137.0 298.257222101 Attribute Table Table containing attribute information associated with the data set. Producer defined Date_Time Date and time that data point was collected in local Pacific Standard Time, yyy-mm-dd hh:mm:ss.sss. Producer defined Unknown Longitude Longitude coordinate of data point (NAD83 (2011)). Producer defined 121.64894 121.667058 Decimal Degrees Latitude Latitude coordinate of data point (NAD83 (2011)). Producer defined 38.285711 38.350002 Decimal Degrees Easting_m Easting projected coordinate of data point - NAD83(2011), UTM Zone 10. Producer defined 616525.65 618056.1 Meters Northing_m Northing projected coordinate of data point - NAD83(2011), UTM Zone 10. Producer defined 4238359.71 4245512.56 Meters Ellip_Ht_m Height of data point with reference to the ellipsoid. Producer defined -290.29 220.24 Ortho_Ht_m Elevation with reference to Geoid 12A. Producer defined -9.8 1.03 Meters Hor_Acc_m The uncertainty associated with positioning of the survey platforms, estimated by computing the standard deviations of the GNSS rover positions relative to the base station using Waypoint Grafnav. Producer defined 0.02 33.01 Meters Vert_Acc_m The uncertainty associated with positioning of the survey platforms, estimated by computing the standard deviations of the GNSS rover positions relative to the base station using Waypoint Grafnav. Producer defined 0.03 41.37 Meters The entity and attribute information provided here describes the tabular data associated with the data set. 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 data set. The entity and attribute information was generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information. U.S. Geological Survey - Science Base Mailing and Physical

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov Bathymetry data are available as both a comma-delimited text file and a shapefile, and include the associated metadata. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Shapefile and comma-delimited text 28.5 https://www.sciencebase.gov/catalog/file/get/56671eb2e4b06a3ea36c8bf2 https://doi.org/10.5066/F7RX9954 Data can be downloaded using the Network Resource links. The first link will begin a direct download of the data. The second link points to the landing page for the entire data release. None. 20201019 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060-5792 US 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998