DOCUMENTATION FOR STR_EDGE 02/09/01 ================================================================================ COMPREHENSIVE COVERAGE DESCRIPTION ---------------------------------- DATA LAYER SUMMARY Date of Entry: 02/09/01 Coverage Name: STR_EDGE Path: \JAMAICA\JAMVILL Description: street edge, Route 30, village of Jamaica, Vt Feature: LINE Status: 2 Available: 02/08/01 DATA MANAGER Jeff Nugent Windham Regional Commission 139 Main Street, Suite 505 Brattleboro, VT 05301 802-257-4547 DATA AUTOMATION Jeff Nugent Windham Regional Commission 139 Main Street, Suite 505 Brattleboro, VT 05301 GEOGRAPHIC AREA and TILE STRUCTURE Tile Structure: NONE (Avg.size: 0kB) Area: village of Jamaica, Vermont DATA SOURCE & FORMAT Source Map: 1:5000 orthophoto (scanned) and other supplimental data Source Date: 1991 Data Format: pcArc/Info Source Scale: 1:5000 Projection : State Plane meters Source Media: digital Datum: NAD 1927 SOURCE DESCRIPTION The main data source used was a scanned version of the 1991 1:5000 Vermont orthophoto sheet for Jamaica. It is based on aerial photographs taken in 1990. The image was created by John Whitman of Readsboro, Vermont, who scanned and registered the image to Vermont State Plane coordinates. In several places, GPS points were taken to verify the edge of the street. Field visits were also made in 2000 to further refine the data. ACCURACY & TOLERANCES Resolution: Fuzzy: 0.000 Dangle: 0.000 FEATURE ACCURACY (in meters) The accuracy of this coverage is somewhat variable is probably no more than 1 to 2 meters. There are several reasons for this error. The image, being scanned from a paper orthophoto, is not as sharp as conventional digital orhtophotos produced by the state of Vermont. Also, there appeared to be a slight discrepancy at some locations when a 500 meter state plane coordinate grid DOCUMENTATION FOR STR_EDGE Page 2 ================================================================================ FEATURE ACCURACY (in meters), continued ... was compared to the grid lines on the orthophoto. The variability observed would make one think this is not solely a registration error but a result of the shrinkage and expansion of the source paper orthophoto. DATA AUTOMATION Dates: December 2000 Software: pcArc/Info 3.5.2; ArcView 3.2 Device: n/a (Resolution: 0.000) Maximum RMS: n/a Update Schedule: none planned Last Update: 05/30/01 QUALITY CONTROL No formal quality control, other than verification using GPS, was performed. DESCRIPTION, FEATURE DEFINITION, METHODOLOGY, etc. This coverage contains the location of the edge of Route 30 in the village of Jamaica, Vermont. The coverage was created to give a general impression of the location of the road in the village A combination of data sources was used to locate the edge of Route 30. The street edge was first delineated in ArcView using a scanned version of the Vermont orthophoto covering the village. Field visits, ground photographs, and GPS points were then used to do final verification and fine tuning of the street edge. LIMITS ON DATA USE & INTERPRETATION This coverage was created to give a genearl feel for the overall location of Route 30 in the village of Jamaica. Its primary purpose is cartographic; that is, to serve as a base map reference coverage for mapping in the village. While the location of the street edge is probably within 1 (or possibly 2) meters of its true location, one should not use this coverage to determine actual pavement width. POLYGON ATTRIBUTE DESCRIPTIONS: NONE. ARC ATTRIBUTE DESCRIPTIONS: NONE. ANNOTATION DESCRIPTION: NONE. COVERAGE HISTORY & DEVELOPMENT DESCRIPTION: NONE. COVERAGE UPDATE DOCUMENTATION: NONE.