Running the HK/SED Analysis Software

HK/SED Analysis Data Path

The HK/SED Analysis Software processes subsets of the IRAC Housekeeping and Special Engineering Data from the HK/SED database. It can be run from the command line on systems with access to the database, or remotely (both interactively and automatically) over the internet (okay....soon you can do this).

The software consists of three primary components:

  1. The HKQuery program operates on a file or list of files from the HK/SED database. It can be used to do any or all of the following: HKQuery can make use of a optional files containing commands, query rules, an extraction list, or row restrictions. It produces a data table as output either in FITS format or (by default) in HK-ASCII format, which is human-readable.

  2. HKHisto produces a histogram of the data from one HK/SED keyword in an HK-ASCII file. It allows the user to interactively resize, change data (if multiple HK/SED keywords are available), adjust axis limits, titles, and produce statistics for plotted data.

  3. HK2D plots the data from up to four HK/SED keywords in a HK-ASCII file against another HK/SED keyword (the SCET time by default). It can also plot merged commands as a function of time. It allows the user to interactively resize, change data, adjust axis limits and titles, view statistics, and choose which commands to plot.

Both HKHisto and HK2D can produce an Encapsulated PostScript representation of the plots they contain.

Running From the Command Line

The three HK programs are meant to be run together, such that the output of HKQuery is piped to the plotting programs. For instance, the following line will use HKQuery to extract the four HK keywords CTTEMP, CTTEMP4, CTTEMP6, and CTTEMP8 from the HK data file ../20020518_lff_a.hk.fit (a FITS format file) and pipe the results to HK2D which is being asked to plot all four of these items:

HKQuery -e CTTEMP,CTTEMP4,CTTEMP6,CTTEMP8 ../20020518_lff_a.hk.fit | java HK2D -y1 CTTEMP -y2 CTTEMP4 -y3 CTTEMP6 -y4 CTTEMP8

The resulting plot:

The capabilities and command line arguments available to each of the HK Analysis programs is outlined in greater detail in the program-specific documentation:

Other documents of interest include: