Import SEGP1

(This functionality is available with the Input / Output module)

Imports SEGP1 data.

Refer also to the Import dialog box topic.

Before importing a SEGP1 file, you should first ensure that you carry out the following:

  1. Determine the projection and units that have been used in the SEGP1 file. It will usually be necessary to view the SEGP1file in a text editor and inspect the comment lines to obtain or verify this information.
  2. Use the Utilities/File/New command to create a new database ensuring that it is created on the same projection as the SEGP1 file, or alternatively on a plane projection.
  3. Use the Utilities/Configure/Units command to set the units to those contained in the SEGP1 file.
    • Linear Units:
      The linear co-ordinates and elevations in the SEGP1 file will be interpreted as feet, metres etc. according to the Linear setting in Configure/Units.
    • Angular Units:
      Latitudes and Longitudes in the SEGP1 file will be interpreted as Degrees, Minutes and Seconds (DDD.MMSS), unless the Angular setting in Configure/Units is set to Gons. If Gons is set, then the Latitudes and Longitudes will be interpreted as Gons to the precision of 5 decimal places.
    • Co-ordinate Units:
      If the database is a plane grid, only linear co-ordinates in the SEGP1 are read. Points in the SEGP1 file without linear co-ordinates are ignored, as latitude and longitude are meaningless in a plane.
      If the database is a projection and the Co-ordinate units are set to Geographic, then the Latitude and Longitude in the SEGP1 file are read. If the Latitude and Longitude are not present in a SEGP1 record, the linear co-ordinates are read instead.
      If the database is a projection and the Co-ordinate units are set to grid, then the linear co-ordinates in the SEGP1 file are read. If the linear co-ordinates are not present in a SEGP1 record, or do not fall within the projection (say if they have been truncated), the Latitude and Longitude are read instead.

  4. If the SEGP1 file co-ordinates do not have decimal points, ensure that you use the Utilities/Configure/Co-ordinates command and set the co-ordinate and elevation precision to the number of decimal places that must be applied to the SEGP1 co-ordinates and elevations.
    When LISCAD encounters co-ordinates in a SEGP1 file without decimal points, the precision settings are used to govern how the co-ordinates are interpreted.

Note:

Line names:

The first 8 characters of the SEGP1 Line name are used as the feature code for the line and associated points.

If line name is blank, the system interprets this record as a point only and it is given the currently set default code and attributes.

Shotpoint Number:

The SEGP1 Shotpoint Number is interpreted as the Point Identifier.