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Function: get_IFO12()

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get_IFO12(FILE *fp1, FILE *fp2, FILE *fp1lock, FILE *fp2lock, int n, float *out1, float *out2, float *srate1, float *srate2)
This function gets real interferometer output (IFO) data from two detector sites.

The arguments of get_IFO12() are:

fp1: Input. A pointer to a file that contains the interferometer output (IFO) data produced by the first detector.
fp2: Input. A pointer to a file that contains the interferometer output (IFO) data produced by the second detector.
fp1lock: Input. A pointer to a file that contains the TTL lock signal for the interferometer output produced by the first detector.
fp2lock: Input. A pointer to a file that contains the TTL lock signal for the interferometer output produced by the second detector.
n: Input. The number $N$ of data points to be retrieved.
out1: Output. out1[0..n-1] is an array of floating point variables containing the values of the interferometer output produced by the first detector. These variables have units of ADC counts. out1[i] contains the value of the whitened data stream $o_1(t)$ evaluted at the discrete time $t_i=i\Delta t_1$, where $i=0,1,\cdots,N-1$ and $\Delta t_1$ is the sampling period of the first detector, defined below.
out2: Output. out2[0..n-1] is an array of floating point variables containing the values of the interferometer output produced by the second detector, in exactly the same format as the previous argument.
srate1: Output. The sample rate $\Delta f_1$ (in Hz) of the first detector. $\Delta t_1:=1/\Delta f_1$ (in sec) is the corresponding sampling period of the first detector.
srate2: Output. The sample rate $\Delta f_2$ (in Hz) of the second detector. $\Delta t_2:=1/\Delta f_2$ (in sec) is the corresponding sampling period of the second detector.

get_IFO12() consists effectively of two calls to get_data(), which is described in detail in Sec. [*] It prints out a warning message if no data remains for one or both detectors. For that case, both out1[] and out2[] are set to zero.

Authors: Bruce Allen, ballen@dirac.phys.uwm.edu, and Joseph Romano, romano@csd.uwm.edu
Comments: Currently, get_IFO12() calls get_data() and get_data2(), where get_data2() is simply a copy of the get_data() routine. get_data() should eventually be modified so that it can handle simultaneous requests for data from more than one detector. After this change is made, the function get_data2() should be removed.


next up previous contents
Next: Function: simulate_noise() Up: GRASP Routines: Stochastic background Previous: Example: overlap program   Contents
Bruce Allen 2000-11-19