viewshed1283

U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
Wyoming

Wyoming Viewshed

Metadata:

Identification_Information:

Citation:

Citation_Information:

Originator: Bureau of Land Management
Publication_Date: 2/1/2002
Title: Wyoming Historic Trail Viewshed - UTM12 Datum NAD83
Geospatial_Data_Presentation_Form: vector digital data
Online_Linkage: Wyoming BLM GIS Webpage

Description:

Abstract:: This database for the Oregon, California, Mormon Pioneer, and Pony Express National Historic Trails is comprised of digital topographic data and reference line established using point data gathered with Global Positioning System (GPS) technology which represents only an approximation of the centerline of the trails system. This database, which is to be used in conjunction with ArcView software, is provided to assist the user in analyzing the visibility of any proposed location within 5 miles of the GPS reference line of the trails in order to evaluate effects to the landscape and setting of National Historic Trails in accordance with the National Historic Preservation Act and its implementing regulations at 36CFR Part 800. This data imparts no information relative to land ownership and conveys no right of access to any land. Legal access to or across private land requires permission of the landowner.
Purpose:: To assist in resource planning as it relates to the NHT setting.

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2002

Currentness_Reference: publication date

Status:

Progress: In work
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -111
East_Bounding_Coordinate: -108
North_Bounding_Coordinate: 41
South_Bounding_Coordinate: 43

Keywords:

Theme:

Theme_Keyword_Thesaurus:: REQUIRED: Reference to a formally registered thesaurus or a similar authoritative source of theme keywords.
Theme_Keyword: viewshed

Theme:

Theme_Keyword_Thesaurus: viewshed
Theme_Keyword: viewshed

Access_Constraints: None

Use_Constraints: None

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Larry Neasloney (GIS questions) /Tim Nowak (cultural questions)
Contact_Organization: BLM

Contact_Position: GIS Specialist/ Archeologist

Contact_Voice_Telephone: 307-775-6171/307-775-6035

Contact_Electronic_Mail_Address: larry_neasloney@blm.gov/tim_nowak@blm.gov

Security_Information:

Security_Classification: Unclassified

Native_Data_Set_Environment:

Microsoft Windows NT Version 4.0 (Build 1381) Service Pack 5; ESRI ArcCatalog 8.1.1.649

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report: See process step

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:: viewsheds results from 30 meter dems and lines collected with GPS

Lineage:

Process_Step:

Process_Description:

1.gps line shapefiles are converted to coverages 2. grain tolerance set to 98 meters, weed tol set to 22 3. arcs splined in Arcedit to place a vertice approx. every 100 yards 4. field called 'Radius2' added to table to control viewshed distance to 5 miles. 5. field called 'Offseta' added to table to set observer height at 5 feet. 6. field called 'Offsetb' added to table to set object height at 12 feet. 7. viewshed analysis run using VISIBILITY command in Arc/Info with frequency option 8. field added to output coverage from step 7 called 'Vis-class' 9. in Arcview 'Vis-code' field queried for 'Vis-class' classes. 0 = Not Seen 1-5 = Seldom Seen 6-21 = Moderately Seen

21 = Visible

10. Visibility coverage disssolved using 'Vis-class' field to make redisplay faster and more aesthetically pleasing.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Complete chain
Point_and_Vector_Object_Count: 53368

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Label point
Point_and_Vector_Object_Count: 23928

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 23928

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 4

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: Universal Transverse Mercator

Universal_Transverse_Mercator:

UTM_Zone_Number: 12

Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -111.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.000128
Ordinate_Resolution: 0.000128

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

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: lfo-viewshed1.pat

Attribute:

Attribute_Label: FID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI