Within XRONOS the user has full control of the binning to be used in the
analysis, the way of subdividing a time series and/or grouping the results of
the analysis. To this aim four basic entities are used in most XRONOS
- BINS : these are the time bins of the time series which is/are
being analysed. Note that there can be more than one bin durations,
(e.g. two consecutive time series, one with 0.5 s bins and the other with
2 s bins). In the examples in chapter 3 (walk_through) the input files
contain 743 bins of 1 s.
- NEWBINS : these correspond to the time resolution with which the analysis is
carried out. One of the examples in section 3.1.2 (walk question psd)
shows how to calculate a power spectrum using a 3 s resolution, i.e. newbins
of 3 s. Note that: (i) newbins cannot be shorter than the longest bin
duration of the time series which is/are being analysed; (ii) in many XRONOS
applications (e.g. psd, pss, acf, ccf) the newbin duration is forced
to be an integer multiple of the longest bin duration.
- INTERVALS : an interval is defined by the number of newbins over which the
analysis is carried out. One of the examples in section 3.1.2
(walk question psd) shows how to calculate power spectra for intervals of
64 newbins of 3 s, corresponding to 32 independent Fourier frequencies.
Note that in applications using FFT algorithms (e.g. psd, acf, ccf)
the number of newbins in an interval must be a power of 2.
- FRAMES : a frame consists of the average of the results of the analysis of
one or more contiguous intervals. Each XRONOS QDP file and, therefore, each
plot produced by XRONOS corresponds to a frame. The examples in section
3.1.2 (walk question psd) show how to average the power spectra from 1, 2
or 4 intervals (each of 64 newbins of 3 s) in a frame. Note that in certain
applications (e.g. lc1, lc2 and lc3), a frame consists always of one
Thu 12 Oct 16:35:19 1995