Base Station Correction

Use the Base Station menu option (MAGBASE GX), from Database Tools > Corrections or Tie Line Levelling > Levelling Corrections, to apply a magnetic base station correction to a magnetic channel.

Base Station dialog options

Base station table file

The base station table filename.

Script Parameter: MAGBASE.BASEFILE

Time channel

Select the time reference channel.

Script Parameter: MAGBASE.INTIME

Input data channel

Select the input data channel to correct.

Script Parameter: MAGBASE.INDATA

Output corrected channel

Select the output corrected data channel.

Script Parameter: MAGBASE.OUTDATA

Application Notes

A magnetic base station correction is established by recording the total magnetic field at a fixed ground location during the same time interval that the survey is recorded. The difference between the established value for the base station and the base station readings is the correction that must be applied to the reading taken at the same time in the survey. Corrections must be compiled by date and time and placed in a base station correction table file.

Sample table:

/ Geosoft Base Station Data
			
/
// MagBase.base=63957.000000
// MagBase.long=0.000000
// MagBase.lat =0.000000
// MagBase.x =0.000000
// MagBase.y =0.000000
/
/= Date:date:i
/= Time:time:i
/= Correction:double
/
/ DateTime Correction
93/12/23 23:56:57 25.5
93/12/23 23:56:59 24.59999
93/12/23 23:57:01 24.29999
93/12/23 23:57:03 23.89999
93/12/23 23:57:05 23.49999
93/12/23 23:57:07 23.09999

The table header identifies the established absolute value at the base station location and the location coordinates. The base correction values are listed as columns of Date, Time and Correction.

When the Base Station Correction dialog is run, the date of each line and the time from the time channel is used to extract the appropriate base correction from this base table.