DOCUMENTATION FOR FT_PRINT 02/09/01 ================================================================================ COMPREHENSIVE COVERAGE DESCRIPTION ---------------------------------- DATA LAYER SUMMARY Date of Entry: 02/09/01 Coverage Name: FT_PRINT Path: Description: Building footprints, village of Jamaica, Vt Feature: POLY Status: 2 Available: 05/30/01 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 supplemental 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. Several other data sources were used to help identify the location and general shape of the buildings. These include the stereo pairs for these orthophotos (nominal scale of about 1:30000), stereo pairs for the 1974 orthophoto series (nominal scale of about 1:20000), a coverage of building points produced by WRC in 1996 (which was updated for this project), E911 ESITE data, and various other sources, including rough mapping done by the public to locate their wells and septic systems. Field visits were also made in 2000 to refine building location and shape. ACCURACY & TOLERANCES Resolution: Fuzzy: 0.000 Dangle: 0.000 DOCUMENTATION FOR FT_PRINT Page 2 ================================================================================ FEATURE ACCURACY (in meters) The accuracy of this coverage is quite variable. Where the building edges were obvious on the orthophoto, the error is probably no more than 1 to 3 meters. The reason for this error is as follows. The image, being scanned from a paper orthophoto, is not as sharp as conventional digital orthophotos 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 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. In most cases, even with a clear view of a structure, all the angles and corners were not captured. If the structure was not able to be clearly identified on the orthophoto, it may be located within 5 meters of its true location, but with very little detail on its shape and orientation. In several instances, no building could be identified on the orthophoto and thus the error would be much greater. One building, the Jamaica Fire Station, was constructed after the orthophoto was taken, and thus its dimensions are approximate, though its location in the database is within 5 to 10 meters of its true location. DATA AUTOMATION Dates: December 1999 Software: pcArc/Info 3.5.2; ArcView 3.2 Device: n/a (Resolution: 0.000) Maximum RMS: n/a Update Schedule: none planned unless comments obtained from town Last Update: 05/30/01 QUALITY CONTROL A number of informal quality control procedures have been done. Numerous data sources have been used to check and verify the buildings (air photos from various dates, orthophotos, maps, and ground photos). Field visits were also used to refine building location and shape. DESCRIPTION, FEATURE DEFINITION, METHODOLOGY, etc. This coverage contains rough building footprints for major buildings in the village of Jamaica, Vermont. The coverage was created to give a general impression of the location, size, shape, and orientation of structures in the village and not to map in detail the structures themselves. Those buildings along Route 30 have been verified and mapped to a higher degree of accuracy than other buildings in the village. Buildings are coded with their use, a general description, and a 911 locatable address. The coverage was originally created to help locate wells, septic tanks, and leach fields based upon residents' sketches of their property. Enhancement is being performed to create base maps of Route 30 for conceptual design purposes. A combination of data sources was used to identify, locate, and determine the general shape of all the major buildings in the village. The rough outline of the building (i.e. the building footprint) was then delineated in ArcView using a scanned version of the Vermont orthophoto covering the DOCUMENTATION FOR FT_PRINT Page 3 ================================================================================ DESCRIPTION, FEATURE DEFINITION, METHODOLOGY, etc., continued ... village. Field visits and ground photographs were then used to do final verification and fine tuning of the buildings along Route 30. LIMITS ON DATA USE & INTERPRETATION This coverage was created to give a general feel for the overall location, size, shape, and orientation of buildings 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. It was originally created to help locate wells, septic tanks, and leach fields based upon residents' sketch maps of their properties. POLYGON ATTRIBUTE DESCRIPTIONS ------------------------------ Date of Entry: 12/29/99 Attribute Item Name: CODE (N 5 0) Description: building use code Source: town planning commission ATTRIBUTE DESCRIPTION 10 = residential 20 = outbuilding 30 = trailer 40 = commercial 50 = barn 60 = public 70 = other 80 = condo Note: a number other than a zero in the ones place indicates the number of living units in the building; thus 11 is a single family residence, 43 is a commercial building with three apartments Date of Entry: 12/29/99 Attribute Item Name: DESCRIPT (C 35 0) Description: general description of structure Source: various Date of Entry: 12/29/99 Attribute Item Name: FEATACC (N 1 0) Description: location accuracy Source: WRC ATTRIBUTE DESCRIPTION 1 = clearly visible on 1:5000 orthophoto 2 = not clearly visible on orthophoto 3 = building in this general location, but nothing resembling a building was located on the orthophoto Date of Entry: 02/09/01 Attribute Item Name: ADDRESS (N 11 0) Description: the locatable address number assigned to the building Source: Enhanced 911 ESITE data DOCUMENTATION FOR FT_PRINT Page 4 ================================================================================ POLYGON ATTRIBUTE DESCRIPTIONS, continued ... Date of Entry: 02/09/01 Attribute Item Name: NEWSTR (C 30 0) Description: the full locatable street address (number and road name) Source: Enhanced 911 ESITE data Date of Entry: 02/09/01 Attribute Item Name: STREET (C 30 0) Description: the street name, in E911 format Source: Enhanced 911 ESITE data ARC ATTRIBUTE DESCRIPTIONS: NONE. ANNOTATION DESCRIPTION: NONE. COVERAGE HISTORY & DEVELOPMENT DESCRIPTION: NONE. COVERAGE UPDATE DOCUMENTATION: NONE.