Sample Calculation (Page 1)

Data Entry Screen

The following pages display a sample calculation of the worst case trapped proton fluence in a 600 km polar orbit. The orbital points have been computed previously with Space Radiation. They are stored in the file polar2.orb. The mission duration is about 16 hours.

This is a typical dialog box. It consists of a title displaying what calculation is being performed, various controls for entering parameters, and buttons to close the box.

Title is a description of your calculation that you provide. The title is stored in a database, along with all other details about your calculation. It is used as a description for retrieving this calculation at a later time and for generating reports.

Orbital Trajectory button accesses the a database listing of all orbital trajectory files. You may select the file by filename and title. The filename is displayed in the edit box to the right.

Trapped Proton Model is selected from a list here. The standard model is called AP8. There are two versions of AP8, one for solar maximum (sunspot maximum) conditions, the other for solar minimum conditions. We have chosen AP8MIN here.

Year is the epoch at which the magnetic field is evaluated for trapped proton calculations. Entering zero here selects the standard epoch. You may also enter a year; however, most experts agree that the model extrapolations are unreliable.

Geomagnetic Field Model may be selected from a list of about 20. Normally use the default IGRF (International Geomagnetic Reference Field) here.

Orbit Integration method. Normally the trapped proton flux is evaluated at each point along the orbit. These fluxes are summed to give you the total fluence during the mission, or equivalently, an orbit-averaged flux. If you want to find the point along your orbit with the greatest trapped proton flux, choose the Worst Case method.

Save saves the parameter choices you have made without performing the calculation. This lets you pause data entry and return later.

Execute creates a file based on the entered parameters.

Cancel cancels data entry without saving anything.

Help presents on-line, hypertext help on the calculation and each parameter you need to input.