lidar_10ft_ct

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:

Mark Hoover-primary, Jason Miller, Nick McNamara: CLEAR (Center for Land Use Education and Research), University of Connecticut

Publication_Date: Unpublished Material

Title: lidar_10ft_ct

Geospatial_Data_Presentation_Form: raster digital data

Online_Linkage: <http://clear.uconn.edu/data/ct_dem/ct_dem.htm>

Description:

Abstract:

These elevation data are a research product and not intended for use in management, regulation, litigation, or related activities. They are intended for research, education, and demonstration purposes. The dataset is a digital elevation model for the state of Connecticut. It was created based on the LIDAR mission flown in 2000. The postings were edited to erase erroneous data, and points were added using Digital Raster Graphics to fill in missing areas. The data were edited and the DEM developed in January and February 2007 in cooporation with the University of Connecticut and the Center for Land Use Education and Research. (CLEAR). The final DEM has a pixel resolution of 10ft.

Purpose:

This purpose of this data set is to have a high-resolution digital elevation model (DEM) based on 20 foot postings of LIDAR data collected in 2000 for the state of Connecticut.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: June 2006.

Beginning_Time: unknown

Ending_Date: March 2007

Ending_Time: unknown

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -73.742917

East_Bounding_Coordinate: -71.780628

North_Bounding_Coordinate: 42.053167

South_Bounding_Coordinate: 40.972530

Keywords:

Theme:

Theme_Keyword_Thesaurus: Elevation datasets

Theme_Keyword: DEM, Digital Elevation Model, LIDAR

Place:

Place_Keyword: Connecticut, Long Island Sound

Temporal:

Temporal_Keyword: 2007

Access_Constraints:

These data area available free of charge via the Center for Land use Education and Research.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Mark Hoover

Contact_Organization: University of Connecticut

Contact_Position: Graduate Student

Contact_Electronic_Mail_Address: Mark.Hoover@uconn.edu

Data_Set_Credit:

Mark Hoover-primary contributer/ Jason Miller, Nick Mcnamara - 2006 NASA DEVELOP Project, Center for Land use Education and Research (CLEAR) at University of Connecticut, Storrs, CT

Native_Data_Set_Environment:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722

Data_Quality_Information:

Lineage:

Process_Step:

Process_Description: Dataset copied from CLEAR server.

Process_Date: June 9

Process_Step:

Process_Description: Converted LIDAR text files into MS Access Format.

Process_Date: Unknown

Process_Step:

Process_Description: Made X,Y Event Layers from MS Access LIDAR files.

Process_Date: Unknown

Process_Step:

Process_Description: Edited Layers to remove any "null" values.

Process_Date: Unknown

Process_Step:

Process_Description:

Exported event layers into shapefiles with defined projection CT State Plane NAD 83 feet.

Process_Date: Unknown

Process_Step:

Process_Description:

Manually edited shapefiles. Added additional points in areas having large gaps in LIDAR points by on screen digitizing from 1983 Digital Raster Graphic maps with 10' contour lines. Deleted some erroneous points of incorrect extreme high elevations. Deleted approximately 200,000 erroneous points in the Mystic area, then digitized gaps from DRG. Set all elevations below 0 to have a value of 0. Added points along coastal shore lines and river shore lines that defined shoreline based on DRGs. Finally points were added to fill in missing areas over lakes using elevation given in DRG.

Process_Date: Unknown

Process_Step:

Process_Description:

Merged the 415 shapefiles into 18 different sections covering the entire state. This was done to avoid hardware constraints from interpolation methods.

Process_Step:

Process_Description:

In order to avoid merging errors each of the 18 sectional shapefiles was given an overlaping boundary. The boundaries were generated from the 4 surronding LIDAR shapefiles. The boundaries were approximately 500ft.

Process_Date: Unknown

Process_Step:

Process_Description:

Interpolated each of the 18 LIDAR sections with the ESRI ArcMap Geoprocessing Wizard. Method used was Radial Basis Function Multiquadric, with 8 neighbors, select at least 4.

Process_Date: Unknown

Process_Step:

Process_Description: Exported the Radial Basis Function output to 10ft cell size.

Process_Date: Unknown

Process_Step:

Process_Description:

The raster output was then visually inspected for any errors. Any extremely low, high, or discontinous areas were then edited. The editing process involved going back to the LIDAR shapefiles and manually changing the elevation values of the erroneous points.

Process_Step:

Process_Description:

Ran the interpolation process again on the 18 edited shapefiles. The same perameters were used; Radial Basis Function multiquadric with 8 neighbors, select at least 4.

Process_Step:

Process_Description: Exported the RBF output to 10ft resolution.

Process_Step:

Process_Description:

Each of the 18 output rasters were then clipped to remove areas of "no data", or areas outside of the state of CT. Areas of "no data" were clipped using manually edited polygons. Areas outside of CT were removed by using the CT DEP boundary shapefile with a 200ft buffer.

Process_Step:

Process_Description:

Mosiacked the 18 output rasters into one raster encompasing the state of CT. The mosiacking was done in Erdas IMAGINE Mosiac Tool. The mosiac was set to an average overlay, and the output was set to 16 bit unsigned integer. This created an output with only whole integer (i.e., feet) values.

Process_Date: Unknown

Process_Step:

Process_Description: Metadata Created.

Process_Date: 3/29/07

Process_Step:

Process_Description:

The ocean pixels in the 5 coastal sections were set to zero using an edited version of the hydrography layer from the CT DEP. The hyrdography layer was edited so that only the areas equal to zero elevation were used. This polygon underwent further editing using 2004 DOQQs from the CLEAR website, to ensure that all and only the ocean were covered by the polygon. This polygon was then reclassed to 0 and multiplied by the 5 different coastal rasters, using ArcGIS Raster Calculator.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Grid Cell

Row_Count: 39224

Column_Count: 53298

Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Lambert Conformal Conic

Lambert_Conformal_Conic:

Standard_Parallel: 41.200000

Standard_Parallel: 41.866667

Longitude_of_Central_Meridian: -72.750000

Latitude_of_Projection_Origin: 40.833333

False_Easting: 999999.999996

False_Northing: 499999.999998

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: row and column

Coordinate_Representation:

Abscissa_Resolution: 10.000000

Ordinate_Resolution: 10.000000

Planar_Distance_Units: survey feet

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257222

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: Lidar_10ft_CT

Attribute:

Attribute_Label: ObjectID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Value

Attribute:

Attribute_Label: Count

Distribution_Information:

Resource_Description:

Downloadable Data available at <http://clear.uconn.edu/data/ct_dem/ct_dem.htm> - the Center for Land Use Education and Research at the University of Connecticut, Storrs. WBYoung Building.

Distribution_Liability:

Distributor assumes no liability as a result of damages incurred by the use or misuse of this data set.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Transfer_Size: 1337.625

Metadata_Reference_Information:

Metadata_Date: 20070516

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Mark Hoover

Contact_Organization: CLEAR (Center for Land Use Education and Research)

Contact_Position: Graduate Student

Contact_Address:

Address_Type: mailing address

Address: 1376 Storrs Rd.

City: Storrs

State_or_Province: CT

Postal_Code: 06269-4037

Country: United States

Contact_Voice_Telephone: 860-486-5239

Contact_Electronic_Mail_Address: Mark.Hoover@uconn.edu

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Extensions:

Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>

Profile_Name: ESRI Metadata Profile