ArcInfo

ESRI ArcInfo Coverage Files are also known as simply as Coverages and less commonly as ADF files.

File listing

Coverages are made up of a set of files within a folder. The folder itself is the coverage name. The files roughly represent different layers, usually representing different types of topology or feature types.

> ls /data/coverage/brazil
aat.adf  arc.adf  arx.adf  bnd.adf  lab.adf  prj.adf  tic.adf  tol.adf

A folder with the name INFO is also part of the coverage. It sits at the same hierarchical level as the coverage folder itself. Therefore, to copy a coverage (using regular file system tools) the coverage folder and the INFO folder must both be copied. The INFO folder holds some catalogue information about the coverage.

> ls /data/coverage/info

arc0000.dat  arc0001.dat  arc0002.dat  arc.dir
arc0000.nit  arc0001.nit  arc0002.nit

Data Access / Connection Method

• CONNECTIONTYPE OGR must be used. The ability to use coverages is not built into MapServer.

• The path to the coverage folder name is required.

• The layer name (feature type) is specified in the DATA parameter

OGRINFO Examples

The directory is the data source. Layers are found within the directory. Using ogrinfo on a coverage directory:

> ogrinfo /data/coverage/brazil -summary

INFO: Open of `brazil'
using driver `AVCBin' successful.
1: ARC (Line String)
2: CNT (Point)
3: LAB (Point)
4: PAL (Polygon)

Using ogrinfo to examine the structure of a layer:

> ogrinfo /data/coverage/brazil PAL -summary

Had to open data source read-only.
INFO: Open of `brazil'
using driver `AVCBin' successful.

Layer name: PAL
Geometry: Polygon
Feature Count: 1
Extent: (1272793.274958, 795381.617050) - (1287078.382785, 807302.747284)
Layer SRS WKT:
(unknown)
ArcIds: IntegerList (0.0)
AREA: Real (18.5)
PERIMETER: Real (18.5)
F_OPER#: Integer (5.0)
F_OPER-ID: Integer (5.0)
OPER: String (2.0)
FCODE: String (10.0)

Map File Example:

LAYER
  NAME Brazil_bounds
  TYPE POLYGON
  STATUS DEFAULT
  CONNECTIONTYPE OGR
  CONNECTION "/data/coverage/brazil"
  DATA "PAL"
  CLASS
    NAME "Brazil Admin Areas"
    STYLE
      OUTLINECOLOR 153 102 0
      SIZE 2
    END
  END
END