Metadata:
- Identification_Information
- Data_Quality_Information
- Spatial_Data_Organization_Information
- Spatial_Reference_Information
- Entity_and_Attribute_Information
- Distribution_Information
- Metadata_Reference_Information
Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey, Iowa Water Science Center, Eastern Iowa Field Unit, Iowa City, IowaPublication_Date: 2006Title: Lake Meyer Boundary (polygon) - Edge of water at lake-surface elevation, 1135.8 ft above NAVD 88Geospatial_Data_Presentation_Form: vector digital dataSeries_Information: Series_Name: Scientific Investigations Map 2933-DPublication_Information: Publisher: U.S. Geological SurveyOnline_Linkage: NoneDescription: Abstract: This data set consists of a digital polygon coverage that defines the shoreline of Lake Meyer in Winneshiek Co., Iowa. The U.S. Geological Survey conducted a bathymetric survey of Lake Meyer in 2003.Purpose: This digital, geographically referenced data set was developed by the U.S. Geological Survey to be used with the Lake Bathymetric project, Eastern Field Unit, Iowa City, Iowa.Supplemental_Information: This coverage was used to define the boundary during generation of the bathymetric three-dimensional surface. To define the shoreline, point locations around the lake are collected with a bow-mounted GPS antenna by touching the bow of the boat to the shoreline. The data points are input into a geographic information system (GIS) software package, ArcInfo, to create a point coverage representing discrete point locations. The polygon coverage defining shoreline is created in ArcInfo by connecting the point locations in the point coverage. Digital orthophoto quads (DOQ's) were used as an aid in adjusting the coverage of the shoreline. This coverage was used as an elevation source (lake-surface elevation) during generation of the bathymetric three-dimensional surface.Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2003Currentness_Reference: ground conditionStatus: Progress: CompleteMaintenance_and_Update_Frequency: None plannedSpatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -91.914513East_Bounding_Coordinate: -91.903974North_Bounding_Coordinate: 43.176495South_Bounding_Coordinate: 43.172672Keywords: Theme: Theme_Keyword_Thesaurus: NoneTheme_Keyword: LakesTheme_Keyword: BathymetryTheme_Keyword: Inland WatersTheme_Keyword: HydrologyTheme_Keyword: USGSPlace: Place_Keyword: IowaAccess_Constraints: This digital, geographically referenced data set was developed by the U.S. Geological Survey to be used with the Lake Bathymetric project, Eastern Field Unit, Iowa City, Iowa.Use_Constraints: The data are released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological SurveyContact_Person: Greg NalleyContact_Position: Project Chief - Eastern Field Unit Supervisory HydrologistContact_Voice_Telephone: 319-337-4191Contact_Facsimile_Telephone: 319-337-4191Contact_Electronic_Mail_Address: gmna...@usgs.govNative_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722Data_Quality_Information: Completeness_Report: Polygon coverage created in ArcEdit by connecting the points in the mey_edgepts83 coverage. This coverage defines the shoreline of the lake for generating the batymetric contour map. An elevation field (elev) was added to the attribute table of the coverage. In ArcEdit, the elev field was set to the value of the lake-surface elevation (1135.8 ft) at the time of the survey.Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Accuracy is tested by visual comparison of source with digital data on an interactive computer system.Lineage: Source_Information: Source_Citation: Citation_Information: Type_of_Source_Media: computer programSource_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2003Source_Currentness_Reference: ground conditionProcess_Step: Process_Description: Data collection: Bathymetry data were collected using the BSS+5 bathymetric survey system with a 200-kHZ intelligent depth sounder (IDS) and a differential GPS (Novatel DGPS beacon or Omnistar receiver) (Specialty Devices, Inc., 2003, Bathymetric Survey System BSS+5 with Omnistar manual: Specialty Devices, Inc., Plano, Texas, 38 p.). The differential GPS has a horizontal accuracy of less than 1 meter (3.281 ft). Bathymetry data were collected and stored in Hypack Max software (ver. 2.12a) (Hydrographic Survey Software, User's Manual, Hypack Max, Coastal Oceanographics, Inc., Middlefield, Conn.). In Hypack Max, the geodetic parameters were set to UTM north, Zone 15, and ellipsoid GRS-1980. Distance (easting and northing) and depth units were both collected in feet.A bar check calibration on the echo sounder was performed at the start of each day following established protocols (U.S. Army Corps of Engineers, 1994, Engineering and design: Hydrographic survey EM 1110-2-1003, chap. 9-3, p. 9-4 to 9-9). This was done to ensure that the echo sounder was calibrated correctly. The bar check involves suspending a 2-ft-diameter flat aluminum plate directly below the echo sounder. The suspension line is marked in 5-ft increments. An initial calibration is made at 5 ft by entering the speed of sound in water (based on water temperature) and then adjusting the offset of the transducer in the computer software. The offset is the draft of the transducer below the lake surface. The aluminum plate is then lowered in 5-ft increments (depending on the range of depths expected to be encountered on the day of data collection) and adjustments in the speed of sound are made until depth readings and the depth of the aluminum plate agree to within approximately 0.1 ft.Data were collected along planned transect lines that were set-up in Hypack Max prior to data collection. Transect lines were spaced at 50-ft intervals perpendicular to the long axis of Lake Meyer. Depending on boat speed, one bathymetry data point was collected at approximately 4- to 8-ft intervals. Data points may be much closer in areas where transect or perimeter runs overlap. Perimeter bathymetry data points were collected while driving the boat around the perimeter of the lake. Target points were collected in areas of the lake where it was too shallow to collect data with the BSS+5 system. Target point depths were collected manually along with a corresponding easting and northing location. The number and location of target points were based on a judgment made in the field that was thought to be spatially representative of the area. In addition, shore point locations (easting and northing) were collected to define the edge of the lake. These locations are collected by touching the bow of the boat to the shoreline at various intervals along the shoreline and recording the position using a bow-mounted GPS antenna.The water-surface elevation of Lake Meyer was determined by tape down (using a steel tape) from a reference point (with a known elevation) on the concrete outflow structure at the dam. The elevation of the reference point was determined by surveying from a reference mark (temporary wooden stake) nearby on the dam. The elevation (1142.388 ft NAVD88) for the reference mark (wooden stake) was determined from third-order benchmarks using an Ashtech Z-12 GPS system. The elevation of the reference point was found to be 1139.180 ft (NAVD88). The water-surface elevation was found to be 1135.76 ft (NAVD88) on July 21, 2003.Post-processing: Bathymetry data were processed using the Hypack Max software. Post-processing involved removing obvious spikes, inputting depths for the time-tagged target points, and editing extraneous points within the shore point files. In addition, tide corrections were applied in Hypack Max to convert depths to elevations. For Lake Meyer data, it was found that some bathymetry data was lost in the deepest parts of the lake (in the old creek channel near the dam). This was due to improper gate selection in SDIDepth software (Specialty Devices, Inc., 2003, Bathymetric Survey System BSS+5 with omnistar manual: Specialty Devices, Inc., Plano, Texas, 38 p.) which controls the range in which data can be collected. SDIDepth is the software which collects seismic digital data but is also where parameters controlling transducer operation are entered. This software communicates with Hypack Max during data collection. Lost bathymetric data for these areas were recovered by exporting the depths recorded by DepthPic software (used to digitize the bottom layer of recent sediment) (Specialty Devices, Inc., 2003, Bathymetric Survey System BSS+5 with omnistar manual: Specialty Devices, Inc., Plano, Texas, 38 p.) into XYZ format. The processed bathymetry data in Hypack Max also were exported to XYZ format. A total of three separate files were exported into XYZ format: (1) the transect and perimeter bathymetric data; (2) the shore point location data; (3) and the target point data. All three XYZ files were then converted to ASCII text files for input into ESRI-ArcGIS (ver. 8.3).NOTE: All bathymetry data processed in Hypack Max and subsequently exported to XYZ and text files were based on an incorrect water-surface elevation (1138.97 ft instead of 1135.76 ft) due to transcription error. Corrections were not made in Hypack Max or the XYZ and text files but were made in the coverage INFO files in ARC.Generation of Bathymetry Map: The output text files (containing northing, easting, and elevation) were input into an arc macro language (AML) script called createpoint in ARC to generate the coverages mey_allpts83, mey_targpts83, and mey_edgepts83. Projections for the coverages were then defined in ARC as UTM zone 15, NAD83, and units in feet.A shapefile (mey_bndry) was created for the lake shore by digitizing (in ArcMap) the points in the mey_edgepts83 coverage. The shapefile was then exported to the coverage (mey_bndry83). In ARC, an elevation attribute "elev" was added to mey_bndry83.aat. In ArcEdit, the "elev" attribute was calculated to a value of 1135.76 ft (NAVD88).Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: VectorPoint_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Complete chainPoint_and_Vector_Object_Count: 1SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Label pointPoint_and_Vector_Object_Count: 1SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chainsPoint_and_Vector_Object_Count: 1SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: PointPoint_and_Vector_Object_Count: 4Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Transverse MercatorTransverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999600Longitude_of_Central_Meridian: -93.000000Latitude_of_Projection_Origin: 0.000000False_Easting: 1640416.666667False_Northing: 0.000000Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pairCoordinate_Representation: Abscissa_Resolution: 0.000004Ordinate_Resolution: 0.000004Planar_Distance_Units: survey feetGeodetic_Model: Horizontal_Datum_Name: North American Datum of 1983Ellipsoid_Name: Geodetic Reference System 80Semi-major_Axis: 6378137.000000Denominator_of_Flattening_Ratio: 298.257222Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988Altitude_Distance_Units: feetEntity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: mey_bndry83.aatAttribute: Attribute_Label: FIDAttribute_Definition: Internal feature number.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.Attribute: Attribute_Label: ShapeAttribute_Definition: Feature geometry.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Coordinates defining the features.Attribute: Attribute_Label: FNODE#Attribute_Definition: Internal node number for the beginning of an arc (from-node).Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Whole numbers that are automatically generated.Attribute: Attribute_Label: TNODE#Attribute_Definition: Internal node number for the end of an arc (to-node).Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Whole numbers that are automatically generated.Attribute: Attribute_Label: LPOLY#Attribute_Definition: Internal node number for the left polygon.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Whole numbers that are automatically generated.Attribute: Attribute_Label: RPOLY#Attribute_Definition: Internal node number for the right polygon.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Whole numbers that are automatically generated.Attribute: Attribute_Label: LENGTHAttribute_Definition: Length of feature in internal units.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Positive real numbers that are automatically generated.Attribute: Attribute_Label: MEY_BNDRY83#Attribute_Definition: Internal feature number.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.Attribute: Attribute_Label: MEY_BNDRY83-IDAttribute_Definition: User-defined feature number.Attribute_Definition_Source: ESRIAttribute: Attribute_Label: ELEVDetailed_Description: Entity_Type: Entity_Type_Label: mey_bndry83.patAttribute: Attribute_Label: FIDAttribute_Definition: Internal feature number.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.Attribute: Attribute_Label: ShapeAttribute_Definition: Feature geometry.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Coordinates defining the features.Attribute: Attribute_Label: AREAAttribute_Definition: Area of feature in internal units squared.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Positive real numbers that are automatically generated.Attribute: Attribute_Label: PERIMETERAttribute_Definition: Perimeter of feature in internal units.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Positive real numbers that are automatically generated.Attribute: Attribute_Label: MEY_BNDRY83#Attribute_Definition: Internal feature number.Attribute_Definition_Source: ESRIAttribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.Attribute: Attribute_Label: MEY_BNDRY83-IDAttribute_Definition: User-defined feature number.Attribute_Definition_Source: ESRIAttribute: Attribute_Label: IDDistribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Lake Bathymetric Project, U.S. Geological Survey, Iowa City, IowaContact_Person: Greg NalleyContact_Position: Project ChiefContact_Address: Address_Type: mailing addressAddress: PO Box 1230City: Iowa CityState_or_Province: IowaPostal_Code: 52244Country: USAContact_Voice_Telephone: 319-337-4191Contact_Facsimile_Telephone: 319-358-3606Contact_Electronic_Mail_Address: gmna...@usgs.govResource_Description: NoneDistribution_Liability: The Lake Bathymetric project of the Eastern Field Unit, the Water Resources Discipline (WRD), and the U.S. Geological Survey make no guarantee nor offer any warranty concerning the accuracy, condition, or application of the information contained in these geographic data.The burden for determining fitness for use of this data lies entirely with the user. Although these data have been processed successfully on computers of WRD, no warranty, expressed or implied, is made by WRD regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty.In no event shall the WRD have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of the delivery, installation, operation, or support by WRD.Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Transfer_Size: 0.028Metadata_Reference_Information: Metadata_Date: 20060725Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological SurveyContact_Person: Mike LinhartContact_Position: HydrologistContact_Address: Address_Type: mailing addressAddress: PO Box 1230City: Iowa CityState_or_Province: IowaPostal_Code: 52244Country: USAContact_Voice_Telephone: 319-337-4191Contact_Facsimile_Telephone: 319-358-3606Contact_Electronic_Mail_Address: slin...@usgs.govMetadata_Standard_Name: FGDC Content Standards for Digital Geospatial MetadataMetadata_Standard_Version: FGDC-STD-001-1998Metadata_Time_Convention: local timeMetadata_Access_Constraints: NoneMetadata_Use_Constraints: NoneMetadata_Extensions: Online_Linkage: Profile_Name: ESRI Metadata ProfileGenerated by mp version 2.8.6 on Tue Jul 25 09:57:17 2006 c80f0f1006
