Spacecraft.ParticleFluxTimes(Variable, Variable, Variable, Variable) Method

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Description

Determines when the spacecraft crosses into or out of a region with a certain level of flux. The ParticleFluxTimes method uses the NASA AP-8 and AE-8 particle flux maps to calculate the omnidirectional flux of the specified particle type with the energy level specified by minimumEnergy. The AP/AE maps contain collected data of proton and electron fluxes in the Earth's radiation belt with energy ranges from 0.04 MeV to 7 MeV for electrons and from 0.1 MeV to 400 MeV for protons. See the help file for links to more detailed documentation on the AP/AE maps. The user has the option to specify epoch and longitude offsets to include in the flux calculation.

 

 

For more detailed information on the particle flux models, please see the Goddard Space Flight Center's description here: http://ccmc.gsfc.nasa.gov/modelweb/magnetos/aeap.html

 

Timing Precision Mode

This page describes functionality in nanosecond timing precision mode.

Click here to see the documentation for this object in millisecond timing precision mode.

 

Note: This is an interval method. See the Interval Methods page for more information.

Note: This method has a state. See the Methods and Properties with State page for more information.

 

Method Signature

Spacecraft.ParticleFluxTimes(

Variable fluxThreshold,

Variable minimumEnergy,

Variable particleType,

Variable solarActivity)

 

 

Arguments

fluxThreshold

Description:

Flux threshold for which events should be reported.

Units:

particles/(cm2 s)

Valid Range:

fluxThreshold > 0

 

 

minimumEnergy

Description:

Minimum energy of particles contributing to the flux. Energy values for Electrons range from 0.1 to 7.0 MeV; for Protons from 0.1 to 400.0 MeV.

Units:

MeV

Valid Range:

minimumEnergy > 0

 

 

particleType

Description:

The type of particle for which flux will be computed.

Valid Values:

Value

Label

0

electrons

1

protons

 

 

 

solarActivity

Description:

The solar activity level of the flux model. The AP-8/AE-8 flux maps use the 1964 IGRF Magnetic Field model when modeling solar minimum, and the 1970 IGRF Magnetic Field model when modeling solar maximum.

Valid Values:

Value

Label

0

solar minimum

1

solar maximum

 

 

 

 

Return Value

Type:

string

 

 

Returns a string containing the entrance or exit time for any flux threshold crossings.

 

The FF_Preferences.IntervalEventReportingBehavior property controls whether the start and end of propagation are reported as events. By default, if entry into high flux starts before the beginning of the propagation span, FreeFlyer will label the start of the propagation as the entry into high flux. If the time in high flux extends past the end of the propagation span, FreeFlyer labels the end of propagation as the exit from high flux.

 

Syntax

myString1 = mySpacecraft1.ParticleFluxTimes(myVariable1, myVariable2, myVariable3, myVariable4);

 

 

Example 1

This example demonstrates how to generate a report of times when the calling Spacecraft enters and exits areas of high particle flux. The method returns the arguments used, entry and exit times, and duration in the area of high flux.

 

Spacecraft Spacecraft1;

 

Variable fluxThreshold = 5; // particles/(cm^2 s)

Variable minEnergy = 10;    // MeV

Variable particleType = 1;  // Protons

Variable solarActivity = 1; // Solar Maximum

 

// *** For Millisecond Mode Only ***

While (Spacecraft1.ElapsedDays < 1 );

 

          Report Spacecraft1.ParticleFluxTimes(fluxThreshold, minEnergy, particleType,  solarActivity) to "ParticleFluxEncounters.txt";

          Step Spacecraft1;

 

End;

 

Or

 

// *** For Nanosecond Mode Only ***

While (Spacecraft1.ElapsedTime < TIMESPAN(1 days));

 

          Report Spacecraft1.ParticleFluxTimes(fluxThreshold, minEnergy, particleType,  solarActivity) to "ParticleFluxEncounters.txt";

          Step Spacecraft1;

 

End;

 

 

Output:

 

Note: Output generated using nanosecond timing precision mode.

 

Particle Flux Threshold: 5 protons / cm^2 / sec

Energy:                  > 10 MeV

Flux Model:              Solar Maximum

 

High Flux Entry Epoch                Exit Epoch                                                                  Duration(min)

Jan 01 2020 00:01:13.095703125   Jan 01 2020 00:11:00.498046875    9.790039063

Jan 01 2020 01:36:47.446289062   Jan 01 2020 01:51:15.585937500   14.468994141

Jan 01 2020 03:12:41.938476562   Jan 01 2020 03:30:09.082031250   17.452392578

Jan 01 2020 04:52:41.791992187   Jan 01 2020 05:07:14.545898437   14.545898438

Jan 01 2020 06:34:10.781250000   Jan 01 2020 06:40:12.304687500    6.025390625

Jan 01 2020 12:04:37.514648437   Jan 01 2020 12:12:29.780273437    7.871093750

Jan 01 2020 13:41:54.624023437   Jan 01 2020 13:55:25.048828125   13.507080078

Jan 01 2020 15:19:45.717773437   Jan 01 2020 15:36:35.361328125   16.827392578

Jan 01 2020 16:58:14.165039062   Jan 01 2020 17:14:31.142578125   16.282958984

Jan 01 2020 18:39:43.154296875   Jan 01 2020 18:50:50.244140625   11.118164063

Jan 01 2020 23:07:04.658203125   Jan 01 2020 23:14:57.290039062    7.877197266

 

 

 

See also

Spacecraft Object

Spacecraft.ParticleFluxTimes

Spacecraft Propagation Guide

Coverage and Contact Analysis Guide