Table of Contents ECSS Model Page
Background Information Magnetic field
Positional version

Overview

This implementation of the magnetic field models runs in combination with the coordinate grid generator. SPENVIS verifies if a coordinate grid has been generated prior to accessing the model page. If not, an error message is displayed with a link to the coordinate grid generator. Please note that running the grid generator will delete all existing output resulting from models that use the coordinate grid.

The magnetic field models can be evaluated over the following domains:

  1. one single geographical point, with one of the model parameters as an independent variable;
  2. a one-dimensional range of geographical points;
  3. a two-dimensional map in latitude and longitude, at fixed altitude and universal or local time.

The input parameters and options for the models are described below. When the input form has been completed, pressing the button will start the calculation and bring up the "Results" page.

Model parameters

The only parameter for the internal field model (DGRF/IGRF) is the magnetic field epoch. If an external field is selected, the day of year and other parameters (depending on the selected model) have to be entered. Finally, the local pitch angle value has to be specified.

If the coordinate grid generated previously is of the type "single geographic position", a range of one of the model parameters (epoch, pitch angle or day of year, if an external field is selected) can be specified. For other coordinate grid types (profile, world map), this option is not available. The parameter range is defined by specifying the last value in the range, and the increments between the first and last value. The parameter can be incremented with a fixed step size, or the number of values (with linear or logarithmic spacing) can be specified.

By default, the magnetic field line tracing routines have a number of failsafes to avoid tracing open or very long field lines. These failsafes can be overriden by advanced users, but this may cause unexpected results!

Results

The magnetic field models produce the files listed in the table below. A description of the file formats can be brought up by clicking on their description in the table.

The report file spenvis_bpp.html contains the input parameters and summary tables. The spenvis_bpo.txt file contains magnetic field strength and vector components, L values and other parameters for each grid point.

Output files generated by the magnetic field models
File name Description
spenvis_bpp.html Report file
spenvis_bpo.txt Magnetic field strength and vector components and ancillary parameters for each grid point

To generate plots, select the plot type(s), options and graphics format, and click the or button. The current page will be updated with the newly generated plot files.

Last update: Mon, 12 Mar 2018