SAAPS, Version 1.01

Superposed Epoch Analysis Help

The Superposed Epoch Analysis (SEA) tool lets you analyse the behaviour of a space environment parameter centred on a list of events.

The steps involved to perform an analysis are outlined below.
 

Event List

First, a series of events must be given. These can either be written directly into the event list field, or be copied-and-pasted from a text editor. The format is YYYY MM DD hh mm ss, where each event is given on a separate line. All times are in UT.

The dates are read from left to right which means that not all fields needs to be specified. For example, the two events

2000 07 12 15
2000 03 21 12 01
are both valid. The first event time will be July 12, 2000, 15:00 UT, and the next will be March 21, 2000, 12:01 UT. The events need not to be ordered in time.

If three or less events are entered then one curve for each event will be plotted. If more than three events are selected then only the statistics will be plotted. See the plot figures at the end of this document for an illustration.
 

Database

Select one object in the database list.

Use the Inspect button to view the meta data.

Event Window

Based on each event in the event list a number of time periods of data will be loaded from the SAAPS database. The event window specifies the start and end time for each period relative to the times in the event list. The start and end times can be given in minutes, hours, or days.

Field

After a database object has been selected the data fields are displayed in the field list. Select one field.

Plot Events

Push this button to plot the events. The plot will appear in a new window. The plot itself can be modified from a menu bar in the plot window. Basic operations such as choosing line/points and setting scaling are available.

Random List

It is useful to compare the events with some randomly chosen events. These can be specified in the random list.

Number of Random Events

Instead of manually typing in a random event list one can instead specify the number of random events that should be generated.

Generate Random List

When this button is pushed a list of random events will be produced and displayed in the random list. These events can afterwards be edited.

Plot Random Events

This will produce a plot of the random events in a new window.

Plot events window

The figure below shows the plot of the two selected events with a time window of +/-12 hours. The plot shows the >10 MeV protons from the GOES-08 satellite for the July 14 and November 8 proton events. Time zero is relative the time of the two events.

Plot random events window

The figure below shows the mean and the +/- one standard deviation of the ten random events.


Peter Wintoft
Tuesday, October 23, 2001