Export Profiles to GM-SYS

The Pdepth > Export Profiles to GM-SYS option (GMSMULTI GX) creates GM-SYS Profile Modelling models from all the selected lines in a database in one invocation. You may also include up to 15 surfaces and observed gradient data from channels for inclusion in the model.

The option is also available in Project Explorer from the context menu GM-SYS 2D Models > New GM-SYS 2D  Model >From each Selected Database Line.

New GM-SYS Model from each Selected Line dialog options

Root name for models	The root name of the GM-SYS Profile Modelling models. The line # will be appended to this root name.
Magnetic channel	Magnetic anomaly channel.
Magnetic elevation channel  OR	Magnetic observation elevations (+ up).
Constant magnetic elevation	Constant magnetic observation elevation; only used if no channel is specified as the magnetic elevations.
Gravity channel	Gravity channel (mGal, either Bouguer anomaly or free-air anomaly.
Gravity elevation channel  OR	Gravity observation elevations (+ up).
constant gravity elevation	Constant gravity field elevations, only used if no channel is specified as the gravity elevations.
Topography channel  OR	Topography elevation channel (+ up).
Constant topography elevation	Constant topography elevation, only used if no channel is specified as the topography channel.
Distance units	Choose the distance units from the list. All distance units (including elevations) must be expressed in this unit.
Max number of points in profile	The maximum number of points to use in the model profile. If the data profile has fewer points, the data is used as selected. If the data profile has more points, the profile will be resampled to the maximum points specified here. The standard version of GM‑SYS cannot load models with more than 1000 points so the user is warned if more than 1000 points are specified. An "extended" option for GM-SYS Profile Modelling enables larger models.

Horizons Options

Horizon values are…	All horizon channels must be either elevations (+UP) or depths (+DOWN). Select the proper mode from the list.
Horizon 1 channel	Horizon channel. Values must be in Vertical Distance units as specified above.
Horizon 2 channel	Up to 15 horizon channels may be specified, from shallowest first to deepest. Surfaces may be coincident, but not cross.

Gradient Options

Gradient channel(s)

Horizontal (Mx) & vertical magnetic gradient and six gravity gradient tensor components. Units for magnetic gradient are always nT/m; units for gravity gradients are always Eotvos.

Batch Parameters

This GX will only work interactively.

Application Notes

This GX is very similar to GMSMARK. However, GMSMARK only generates one model from the "marked" portion of the current line. GMSMULTI can generate multiple models and uses all of the selected lines.

Each database line will be written to an XYZ file named "<prefix><Line>_gms.xyz", and the GM‑SYS model file will be created from this data.

Note that XYZGMS converts a multi-segment line into a single-segment profile as shown below. The black line represents the original profile as digitised by the user. The red line is the location of the model profile in real-world X,Y space with values projected perpendicularly onto the model profile. The model-profile azimuth is based on the first and last points in the original profile. The profile location is then shifted to minimize the average mis-fit.

 

If you prefer to use distance along the line as the GM-SYS Profile Modelling X-coordinate, use the DISTCHAN GX (Utility | Make distance channel..) to generate a "X_dist" channel. Create a "Y_dist" channel containing all 0's. Then run the XYCOPY GX (Coordinates | Changes coordinates..) to set the default X,Y to X_dist,Y_dist. After running GMSMARK, you can easily resort the original X,Y by running the XYGET GX (Coordinates | Restore backup XY).