Documentation for PA county boundaries,

PA Albers projection

This dataset contains contains county boundaries for the Commonwealth of Pennsylvania in the PA Albers projection.

The boundaries are presented in two formats: Arc/Info polygons and as a 1-km grid. The polygons include county names in the polygon attribute tables. The grid version sets grid cells on a county boundary to 255, and the remaining cells to zero; the grids contain 320 rows of 540 cells each.

The files for FTP download are

county_alb.e00.gz

County boundary polygons, Arc/Info Export format

bndry_grid.e00.gz

Gridded county boundaries, Arc/Info Export format

county_bnd_1km_pa_alb.bsq.gz

County boundaries, 1-km grid, 1-byte binary array

county_bnd_1km_pa_alb.ddr

LAS DDR file for bouundary grid

Files and directories accessible only from the local ESSC network are

county_alb

Arc/Info coverage for boundary polygons

county_bnd_1km_pa_alb.img

County boundaries, 1-km grid, LAS image format

bndry_grid

County boundaries, 1-km grid, Arc/Info GRID format

Projection and Geolocation Information

This dataset is in an Albers equal area projection centered on Pennsylvania.

Projection parameters:

Name:	Albers Conic Equal Area
Projection units:	meters
Spheroid:	GRS80/WGS84
Datum:	NAD83
1st standard parallel:	40.0° N
2nd standard parallel:	42.0° N
Central meridian:	-78.0° (W)
Latitude of origin:	39.0° N
False easting:	0
False northing:	0

Bounding coordinates:

Projection --

-240000 to 300000 easting

380000 to 60000 northing

Geographic (approximate) --

-81.0° to -74.5° longitude

42.4° to 39.5° latitude

Cell size for gridded data: 1 km by 1 km.

Grid dimensions: 320 lines (rows) of 540 samples (columns) each.