XMM-Newton SAS Home Page
XMM-Newton Science Analysis System


phasecalc (dscalc-2.6) [xmmsas_20060628_1801-7.0.0]

Use Home Page Examples Home Index

Meta Index / Home Page


Description

Given an ephemeris and a list of event tables, phasecalc calculates the phase of each event in each of the tables. The calculated values are stored in a column named PHASE. If the column exists it is overwritten.

phasecalc relies on the event table having a TIME column and the two attributes MJDREF and TIMEZERO.

The time of event n is then:


\begin{displaymath}
t(n) = \texttt{MJDREF} * 86400 + \texttt{TIMEZERO} + \texttt{TIME}[n]
\end{displaymath} (1)

where $\texttt{TIME}[n]$ is the value stored in the TIME column.

An ephemeris is specified in terms of four quantities:

The phase of event n is defined as:


\begin{displaymath}
\phi(n) = \phi_0 + \{ t(n) - t_0 \} \times \nu + \frac{1}{2} \{ t(n) - t_0 \}^2 \times \dot{\nu}\,.
\end{displaymath} (2)



Subsections
Use Home Page Examples Home Index
XMM-Newton SOC/SSC -- 2006-06-28