Identification_Information: Citation: Citation_Information: Originator: US Army Engineer Joint Airborne Lidar Bathymetry Technical Center of Expertise.(ed.) Publication_Date: 20011000 Title: Gull Island Reef, Lake Michigan, Michigan Edition: 1.1 Geospatial_Data_Presentation_Form: XYZ ASCII Larger_Work_Citation: Citation_Information: Originator: Peter Barnes Originator: Guy Fleisher Originator: James V. Gardner Originator: Kristen Lee Publication_Date: 2003 Title: Bathymetry and selected perspective views of 6 reef and coastal areas in Northern Lake Michigan Series_Information: Series_Name: USGS Open-File Report Issue_Identification: USGS OFR 03-120 Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Online_Linkage: Description: Abstract: ArcInfo GRID format generated from 2001 Lidar survey. These data were collected by the SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) system which consists of an airborne laser transmitter/receiver capable of measuring 400 soundings per second. Purpose: The purpose of the survey was to provide bathymetry and albedo dat for utilization in habitat studies. Supplemental_Information: The system operates from a deHavilland DHC-6 Twin Otter flying at altitudes between 200 and 400 meters with a ground speed of about 100 knots. The SHOALS system also includes a ground-based data processing system for calculating acurate horizontal position and water depth. Lidar is an acronym for LIght Detection And Ranging. The system operates by emitting a pulse of light that travels from an airborne platform to the water surface where a small portion of the laser energy is backscattered to the airborne receiver. The remaining energy at the water's surface propogates through the water column and reflects off the sea bottom and back to the airborne detector. The time difference between the surface return and the bottom return corresponds to water depth. The maximum depth the system is able to sense is related to the complex interaction of radiance of bottom material, incident sun angle and intensity, and the type and quantity of organics or sediments in the water column. As a rule-of-thumb, the SHOALS system should be capable of sensing bottom to depths equal to two or three times the Secchi depth. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20010800 Currentness_Reference: Ground Condition Status: Progress: Complete Maintenance_and_Update_Frequency: Unknown Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -085.833000 East_Bounding_Coordinate: -085.780000 North_Bounding_Coordinate: +45.660000 South_Bounding_Coordinate: +45.601400 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: lidar survey Theme_Keyword: Hydrographic Survey Theme_Keyword: Lake Michigan Theme_Keyword: Gull Island Reef Place: Place_Keyword_Thesaurus: None Place_Keyword: Lake Michigan Place_Keyword: Gull Island Reef Access_Constraints: None Use_Constraints: Acknowledgement of the U.S. Army Engineer Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBCTX) would be appreciated in products derived from these data. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Army Corps of Engineers JALBCTX Contact_Address: Address_Type: mailing and physical address Address: 109 St. Joseph Street City: Mobile State_or_Province: Alabama Postal_Code: 36602 Country: USA Contact_Voice_Telephone: (334) 694-3721 Contact_Facsimile_Telephone: (334) 690-3464 Cross_Reference: Citation_Information: Originator: US Army Engineer Joint Airborne Lidar Bathymetry Technical Center of Expertise.(ed.) Publication_Date: 20011000 Title: Boulder Reef, Lake Michigan, Michigan Online_Linkage: http://walrus.wr.usgs.gov/infobank/t/t101lm/html/t-1-01-lm.meta.html Native_Data_Set_Environment: SunOS, 5.8, sun4u UNIX ArcInfo version 8.0.2 Browse_Graphic: Browse_Graphic_File_Name: http://geopubs.wr.usgs.gov/open-file/of03-120/images/map/gull_mapcutL.jpg Browse_Graphic_File_Description: Shaded relief map view of Gull Island Reef Browse_Graphic_File_Type: JPEG Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: SHOALS has demonstrated capabilities that meet US Army Corps of Engineers Hydrographic Survey accuracy requirements for Class 1 surveys and the International Hydrographic Organization nautical charting standards for Order 1. Logical_Consistency_Report: None Completeness_Report: Complete Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: +/- 3 meters (1 sigma) Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: +/- 15 cm (1 sigma) Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Army Corps of Engineers JALBTCX Publication_Date: 20011000 Title: Gull Island Reef, Lake Michigan, Michigan Edition: 1.1 Type_of_Source_Media: CD-ROM Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20010800 Source_Currentness_Reference: Ground Condition Source_Citation_Abbreviation: None Source_Contribution: SHOALS Process_Step: Process_Description: The SHOALS airborne system acquires a tremendous volume of raw data during a single mission. The lidar data are unique and require a specialized Data Processing System (DPS) for post-processing. The DPS main funcions 1) import airborne data stored on high density data tape; 2) perform quality control checks on initial depths and horizontal positions; 3) provide display and edit capabilities; 4) calculate depth and position (XYZ) values for each sounding; and 5) output final positions and depths for each sounding. The depth readings are gridded into a common grid. The gridded data are converted to ArcInfo GRID format using ArcInfo's ASCIIGRID command. Process_Date: 20010900 Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Gull Island Reef, Lake Michigan, Michigan Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 16 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -85.80650 Latitude_of_Projection_Origin: 0.00000 False_Easting: 0.00 False_Northing: 0.00 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 4.0 Ordinate_Resolution: 4.0 Planar_Distance_Units: Meters Geodetic_Model: Horizontal_Datum_Name: WGS84 Ellipsoid_Name: WGS84 Semi-major_Axis: 6378137.00 meters Denominator_of_Flattening_Ratio: 0.003352811 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: gullgrd is an ArcInfo GRID with the following attributes: Cell Size = 4.000 Data Type: Floating Point Number of Rows = 2152 Number of Columns = 1439 BOUNDARY Xmin = 638209.450 Xmax = 643965.45 Ymin = 5051545.406 Ymax = 5060153.406 STATISTICS Minimum Value = -180.200 Maximum Value = -146.200 Mean = -161.207 Standard Deviation = 4.932 Entity_and_Attribute_Detail_Citation: none Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S Geological Survey Contact_Person: Peter Barnes Contact_Address: Address_Type: mailing and physical address Address: MS999 345 Middlefield Road City: Menlo Park State_or_Province: CA Postal_Code: 94025 Contact_Voice_Telephone: 916-329-5265 Distribution_Liability: These data not intended for navigational purposes. Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, these data and information are provided with the understanding that they are not guaranteed to be usable, timely, accurate, or complete. Users are cautioned to consider carefully the provisional nature of these data and information before using them for cisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences. Conclusions drawn from, or actions undertaken on the basis of, such data and information are the sole responsibility of the user. Neither the U.S. Government nor any agency thereof, 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 data, software, information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. Trade, firm, or product names and other references to non-USGS products and services are provided for information only and do not constitute endorsement or warranty, express or implied, by the USGS, USDOI, or U.S. government, as to their suitability, content, usefulness, functioning, completeness, or accuracy. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ArcInfo GRID Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: Fees: None Metadata_Reference_Information: Metadata_Date: 20030130 Metadata_Review_Date: 20030200 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Contact_Person: Kristen Lee Contact_Position: Physical Science Technican Contact_Address: Address_Type: mailing and physical address Address: USGS, MailStop 999, 345 Middlefield Road City: Menlo Park State_or_Province: CA Postal_Code: 94025-3561 Country: USA Contact_Voice_Telephone: (650) 329-5260 Contact_Facsimile_Telephone: (650) 329-5411 Contact_Electronic_Mail_Address: kmlee@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata ("CSDGM version 2") Metadata_Standard_Version: FGDC-STD-001-1998