---++ Quick Start to APEX-SZ Analysis

Overview

  • There are three North American locations for the data, Berkeley, Colorado and Montreal.
  • The data in Montreal are stored on kingspeak.physics.mcgill under /data/ApexSZ_DataArchive/rawdata
  • Data are stored as MBFITS v. 1.6 files. The data are divided into numbered "scans", each in its own subdirectory that is named according to the scan number, e.g. /data/ApexSZ_DataArchive/rawdata/APEX-6242-T-79.F-0011-2007
  • Observation logs are kept in /data/ApexSZ_DataArchive/obslogs
  • Any additional observations will be placed in these locations

Analysis Software

  • The analysis software for APEX-SZ is stored in a CVS repository called APEXSZ_QuickLook (stored on a server in Berkeley)
  • Before you work with the data, you have to check out a local copy of this code. I suggest you check out a copy to your home directory on kingspeak using the command 'apexcvs checkout APEXSZ_QuickLook'
  • If you are working on a Windows machine, several utilities exist for checking out CVS archives, e.g. cygwin, WinCVS, TortoiseCVS
  • The APEXSZ_QuickLook archive has two main subdirectories, APEXSZ_QuickLook/idl and APEXSZ_QuickLook/matlab. This quickstart focuses on matlab

Reading in APEX-SZ Data

  • The first thing you want to do is start matlab, then run the file APEXSZ_QuickLook/matlab/startup.m to set the paths to the analysis software properly

  • The second thing you want to do is create a string containing the path to the correct scan 
>> datadirectory = '/data/rawdata/'
  • Now you are ready to call szd_readscans: 
>> scandata = szd_readscans(5690:5700,datadirectory,'parse_halfscans')
  • This reads in scans 5690 through 5700 and stores the data in a SZD data structure called scandata

Processing Data

  • You can now start processing the data, plotting timestream, noise, performing PCA subtractions, etc.

  • You can plot the timestream by entering 
>> plot(scandata.ts.bolo(num_samples, channel_list))
or using plot_ts which will subsample every 10 points 
>> plot_ts(scandata, channel_list)

  • PCA subtractions can be performed by using the pca function 
>> cleandata = pca(scandata, channel_list, eigenmode_to_subtract)

-- TrevorLanting - 03 May 2007

This topic: APEX_SZ > WebHome > 2007-05-02_AnalysisQuickStart Topic revision: r5 - 2007-06-14 - JamesKennedy
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