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SAAPS, Version 1.01 |
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During times of enhanced energetic (MeV) electron flux the risk of internal charging events increases. By summing the flux over a day one obtains the daily electron fluence. The fluence can be used to determine whether there is an increased risk of internal charging by applying a threshold level.
With this tool the threshold levels for the >0.6 MeV and >2 MeV GOES-8 electron fluence can be found for user submitted anomaly data.
First the events must be entered by pushing the "Edit Events ..." button. A dialogue window appears into which the events can be typed or copy-pasted from a text editor.
Then the non-events must be entered. These are times of when no anomaly were observed. The non-events can either be entered manually by pushing the "Edit Non-Events ..." button or automatically by pushing the "Random Non-Events ..." button. The random events are selected from the dates in the events range but avoiding the event dates.
The optimal time delay and threshold levels can then be found when the "Optimize" button is pushed. A search will be carried out by introducing a time delay between the daily fluence and the events, and by changing the threshold level. The >0.6 MeV and >2 MeV energy levels are searched independently of each other.
The time delay is varied from -5 days to +5 days in one day steps. A time delay of -5 days means that there is a five day forecast possibility from the electron fluence.
The >0.6 MeV threshold level is varied from 107 to 1011 cm-2 sr-1, and the >2 MeV threshold from 105 to 109 cm-2 sr-1.
When the search is finished the result is displayed in the text areas, and the found time delays and threshold levels are shown in their respective text fields.
The result is given in probabilities of whether the predictions are actually observed and whether the observations are predicted. The probabilities must be above 0.5 in order for the model to be useful.
A time delay of 0 (zero) days means that when the electron fluence goes above the threshold level the increased risk of internal charging follows immediately. A time delay of -1 day means that the electron fluence is leading the internal charging with one day, i.e. when the fluence goes above the threshold level the internal charging will follow one day later. A positive time delay means that there is no forecasting.
The time delays and threshold levels can also be altered by changing the values in the text fields. Pushing "Run" will calculate the probabilities for the new values.
Peter Wintoft |
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