Shaded Relief (1:5,000)

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Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: EOEA - MassGIS
Publication_Date: 20050228
Title: Shaded Relief (1:5,000)
Geospatial_Data_Presentation_Form: raster digital data
Online_Linkage:
<http://wsgw.mass.gov/data/gispub/images/elevation/shdrel5k/shdrel5k.zip>
Description:
Abstract:
This raster layer, useful for cartographic display, represents a shaded relief or "hillshade" for the surface terrain of Massachusetts. Its source data were the digital terrain models that were produced as part of the 1:5,000 Black and White Digital Orthophoto imagery project. Cellsize is 10 meters by 10 meters. Each cell has a grayscale value ranging from 1 to 255.
MassGIS stores the statewide image in its Oracle-based ArcSDE geodatabase as IMG_SHDREL5K.
Purpose: Cartographic display
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20050228
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -73.545863
East_Bounding_Coordinate: -69.870162
North_Bounding_Coordinate: 42.909573
South_Bounding_Coordinate: 41.197561
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: hillshade
Theme_Keyword: shaded relief
Access_Constraints: None
Use_Constraints: None
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: EOEA - MassGIS
Contact_Person: Michael Trust
Contact_Position: Sr. Database Administrator
Contact_Address:
Address_Type: mailing address
Address: 251 Causeway Street
Address: Suite 500
City: Boston
State_or_Province: MA
Postal_Code: 02114
Country: USA
Contact_Voice_Telephone: (617) 626-1000
Contact_Facsimile_Telephone: (617) 626-1249
Contact_Electronic_Mail_Address: michael.trust@state.ma.us
Hours_of_Service: 9 AM - 5 PM
Native_Data_Set_Environment:
Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.1850
Data_Quality_Information:
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The source digital terrain model data were collected on analytical stereoplotters at a sufficient density to support generation of 3-meter contours conforming to the National Map Accuracy Standards (+ or - 1.5 meters) at the nominal scale of 1:5,000.
Lineage:
Source_Information:
Source_Scale_Denominator: 1:5,000
Source_Contribution:
Using ESRI's ArcInfo Workstation software, MassGIS ran the TOPOGRID command, using the existing 3-Meter Elevation Contours (1:5,000) layer as input. Working on an Orthophoto Quad Index tile-by-tile basis (clipping the contours out of SDE with a bit of overlap on all sides of the tile), TOPOGRID produced elevation grids based on the contours. The HILLSHADE command then produced the shaded relief grid from the output of TOPOGRID. The hillshade grids were produced with an azimuth of 315 degrees, an altitude of 45 degrees, a Z factor of 1.5, and without the effects of local shadows. To produce a continuous coastline, the outermost breaklines from the Topographic Breaklines layer were appended and edited into polygon coverages, converted to grids, and used the in the SELECTMASK () Grid function. This process allowed all off-shore areas to be coded as NODATA. For some tiles along the coast, there were too few contours to use TOPOGRID. For these, an OQ tile-based area was clipped out of the Digital Elevation Model (1:5,000) and HILLSHADE was run on that. Once grids for all tiles were completed, they were merged into one statewide grid. At this point, any grayscale values of 255 (pure white) within the land portion of the image were changed to 254 and all NODATA was converted to 255 so that when the grid was converted to a tiff image (needed for production of a MrSID image version of the layer), the only 255s would be offshore or in adjacent states, allowing for a white background around valid hillshade data. The grid version was loaded into SDE, after which pyramids were built and statistics generated.
After some experimentation, the TOPOGRID-HILLSHADE approach was chosen over other methods (such as the Surface Analysis > Hillshade tool in ArcGIS' Spatial Analysis extension) because the HILLSHADE command produced the smoothest, most realistic and cartographically pleasing shaded relief image when generated from the already generalized contours, with minimal banding or other visually disturbing artifacts. In a few areas, some banding may be noticeable at large scales, a result of the irregular pattern of original sampling points in the source DTM files.
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 44
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 18821
Column_Count: 30022
Vertical_Count: 1
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: Lambert Conformal Conic
Lambert_Conformal_Conic:
Standard_Parallel: 42.683333
Standard_Parallel: 41.716667
Longitude_of_Central_Meridian: -71.500000
Latitude_of_Projection_Origin: 41.000000
False_Easting: 200000.000000
False_Northing: 750000.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 10.000000
Ordinate_Resolution: 10.000000
Planar_Distance_Units: meters
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
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum of 1988
Altitude_Resolution: 1
Altitude_Distance_Units: meters
Altitude_Encoding_Method: Implicit coordinate
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: shdrel5k.sid.vat
Attribute:
Attribute_Label: OID
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:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: EOEA - MassGIS
Contact_Person: Michael Trust
Contact_Position: Sr. Database Administrator
Contact_Address:
Address_Type: mailing address
Address: 251 Causeway Street
Address: Suite 500
City: Boston
State_or_Province: MA
Postal_Code: 02114
Country: USA
Contact_Voice_Telephone: (617) 626-1000
Contact_Facsimile_Telephone: (617) 626-1249
Contact_Electronic_Mail_Address: michael.trust@state.ma.us
Hours_of_Service: 9 AM - 5 PM
Resource_Description: Data may be ordered in MrSID image format
Distribution_Liability:
Please see the "PURCHASE AGREEMENT FOR DIGITAL DATA PROVIDED BY THE MASSACHUSETTS EXECUTIVE OFFICE OF ENVIRONMENTAL AFFAIRS", online at <http://www.mass.gov/mgis/puragree.htm>.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 64.095
Ordering_Instructions: Order CD-ROM from <http://www.mass.gov/mgis/order.htm>
Custom_Order_Process: Order CD-ROM from <http://www.mass.gov/mgis/order.htm>
Technical_Prerequisites:
MassGIS' data may be used in many standard GIS software products. See each software's vendor for technical prerequisites.
Metadata_Reference_Information:
Metadata_Date: 20150806
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: EOEA - MassGIS
Contact_Person: Michael Trust
Contact_Position: Sr. Database Administrator
Contact_Address:
Address_Type: mailing address
Address: 251 Causeway Street
Address: Suite 500
City: Boston
State_or_Province: MA
Postal_Code: 02114
Country: USA
Contact_Voice_Telephone: (617) 626-1000
Contact_Facsimile_Telephone: (617) 626-1249
Contact_Electronic_Mail_Address: michael.trust@state.ma.us
Hours_of_Service: 9 AM - 5 PM
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Generated by mp version 2.9.12 on Mon Jul 25 14:13:00 2016