How to measure the stability of the receivers
CK 15-Sep-2010
Observing the absorber
The procedures lie on: t00-10@mrt-lx3.iram.es:~/pako/HemtStability
see allan.pako pako> cal /ambient yes /cold no /sky no /tcalibrate 60 ! longer than 60 is not allowed ! pako> set doSubmit no pako> start edit '~/pako/XML/calibrate.xml' modify tcalibrate (total observing time in seconds, e.g. 600) modify tphase time if needed: TimePerPhase, TimePerRecord (dump time / time bin length, e.g. 0.5 sec) on mrt-lx1: 'submitObservingBlock calibrate.xml' to start taking data Look for resulting FITS raw data file, e.g. in observationData/imbfits Identify full scan number, e.g. 20100822s227.
Data reduction
THIS PART IS STILL INCOMPLETE AND MAY NOT WORK.
Routines were originally written by HW.
Create Allan-Stability plot of continuum scan: greg @ plotAllanCK no 20100822s227 CONTI this routines runs a fortran program to calculate the allan variances against time, outputs the data to allan.dat and then plots them. Each line in the input file allan.dat corresponds one variance point. Each column corresponds to a frequency. For continuum observations this can be the 4 4GHz IF channels. Create Allan-Stability plot of WILMA scan: greg @ plotAllanCK no 20100823s72 WILMA 1 11 21 31 41 1 corresponds to the backend part. 11 21 31 41 are the channel numbers to be used for the calculations. These should not be consecutive channels, to avoid any correlation between channels.