In BlueSky, you can define your own periodic loggers with the CRELOG command:

CRELOG MYLOG DT [Header]

This function creates a logger with name 'MYLOG' that, when enabled, will log data at a time interval 'dt'. If you specify a header, created logfiles (which are stored in the output directory specified in your BlueSky settings file) will start with this header on the first line. After calling CRELOG, you can add variables to the logger:

MYLOG add [FROM parent] var1, ..., varn

The variables here are the variables as they are named in the BlueSky source. You can look around these variables while running Bluesky with the LSVAR command. Without arguments, this command will list all the top-level objects that are accessible: traf, sim, and all of the loaded plugins. The member variables of these top-level objects are accessible directly, so these three lines would do the same:

MYLOG ADD lat, lon, alt

or

MYLOG ADD traf.lat, traf.lon, traf.alt

or

MYLOG ADD FROM traf lat, lon, alt

BlueSky's top-level objects can also contain child objects with useful information, such as traf.perf, and traf.asas (for performance data and CD&R data).

After creation, your logger can be enabled/disabled:

MYLOG ON/OFF [dt]