Superposed Epoch Analysis Help
With this tool time series data from the SAAPS database can be analysed by superposing the data centred on user submitted epochs.
To produce a superposed epoch plot the following steps should be made:
- Enter a series of event data, either directly in the event window or from a file using the "Read From File ..." button. One line of data is one event. The format of the data are
Year Month Date Hour Minute Second.
All six fields need not to be present, however the order of the fields is important. E.g., one can just enter Year Month Date.
- Choose an item from the Database list.
- Choose a data field from the Field list.
- Enter the size of the superposed epoch window in the Start and End fields, and select the time unit (days, hours, minutes).
- Push the "Plot Events" button.
If there are three events or less the plot will show the individual time series for each event. If there are more than three events only the statistics will be display. The statistics are the mean and plus-minus one standard deviation.
A comparison plot can also be produced by selecting another user submitted list or selecting events at random.
- Enter the events in the random list window or generate a random event list pushing the "Generate random list" button. The number of random events generated should also be given. The random events are selected from the time period that is spanned by the events in the Event Window.
- Push the "Plot Random Events" button.
Some of the data are high resolution, like the 1-minute ACE data. If the number of events are large and the superposed epoch window extends over several days the data loading can take some time. Therefore, it is usually best to first try with a smaller event window (minutes or hours).
Peter Wintoft, Wednesday, August 29, 2001