Project MAGNET format
Format description for world-wide magnetic survey data
| Item | Characters | Fortran format | Description |
|---|---|---|---|
| A | 1-15 | A15 | Station name/track |
| B | 16-24 | F9.3 | Date |
| C | 25-33 | F9.3 | Colatitude |
| D | 34-41 | F8.3 | East longitude |
| E | 42-51 | F10.3 | Declination |
| F | 52-59 | F8.3 | Inclination |
| G | 60-66 | F7.0 | Horizontal intensity |
| H | 67-74 | F8.0 | North component |
| I | 75-82 | F8.0 | East component |
| J | 83-90 | F8.0 | Vertical component |
| K | 91-97 | F7.0 | Total intensity |
| L | 98-102 | I5 | Altitude |
| M | 103-104 | I2 | Data code |
| N | 105-108 | I4 | Source |
| O | 109-116 | I8 | Serial |
| P | 117-123 | I7 | Element code |
| Q | 124-127 | I4 | GMT |
| R | 128-132 | A5 | Country |
Notes
Item B - date is in units of years with precision of 0.001 year. For example 7 April 2008 = 2008.266.
Items C and D - colatitude (90 – latitude) and longitude are in units of degree with precision of 0.001 degree.
Items E and F - declination and inclination are in units of degree with precision of 0.001 degree. Missing value code is 999.999 but other codes have been used in the past, eg. blanks, 0., 99.999, 999.000.
Items G to K - the other elements are in units of nanoTeslas. Missing value code is 99999. but other codes have been used in the past, eg. blanks, 0., 999999., 88888.(?).
Item L - altitude is in units of tens of metres. Missing value code is -999 but 0 has been used in the past
Item M - data code. 1 - one-off land survey data, 2 - aeromagnetic, 4 - three-component marine data, 5 - satellite data, 6 - marine total intensity data, 9 - repeat station data, 0 - observatory annual means not in observatory annual means file. An asterisk in front of the data code indicates that the record has been changed.
Item N - source number, as listed in file of sources. This is a list of references and letters.
Item O - serial number. The system now used is to start at 1 for each new source.
Item P - one digit for each of the 7 elements E to K. 2 - observed data, 9 - anomalous observed data (more than 1000 nT different from the International Geomagnetic Reference Field (IGRF)), 1 - computed data, 8 - anomalous computed data (more than 1000 nT different from IGRF) - this was introduced in March 1994, 0 - no data.
Item Q – Greenwich Mean Time (GMT) usually given for codes 2, 5 and 6. However if GMT = 0 for data codes (Item M) 1 or 9 it indicates that the data have been reduced to a quiet night-time (LOCAL!) value.
Item R - abbreviated country or state name or quad index (?).
