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Archive structure

Data organization

Each of the data sets that comprise the Swift archive are organized in distinct directories as follows:

To limit the number of files in each of the above directories, data are subdivided in interval of one months and, within these are organized as described above. The time interval directories are named YYYY_NN, where where YYYY is the year and NN defines the month within that year.

       /obs                    /tdrss                    /trend
/2004_12  /2005_01 ...    /2004_12  /2005_01 ...    /2004_12  /2005_01 ...
    |                        |                       |
/sequence                /sequence            /xrt /bat /uvot /misc

The results of the surveys and the derived GRB products will be located in seperate dedicated directories and will be documented here after these data start to arrive in the archive.

The 'obs' data directory structure

The science data are located under the /obs main directory. Each sequence is divided into the following subdirectories :

The /auxil and /log directories are always present for every sequence. The others may or may not be present, depending on the observation type and/or if the instrument was or was not generating data during a specific observation. Specifically the /tdrss directory is typically present only in AT observations, however it may also be present in some calibration PPT observations. Sequences related to triggers that do not generate a slew will contain only data in the /bat directory but not in the /xrt and /uvot directories.
Each of the instrument directory is subdivided in subdirectories. For the /xrt and /uvot directories there are :

The /bat directory structure instead includes the following directories:

The directory structure for a sequence that includes all of the instruments is the following :

 /auxil   /log   /bat  /uvot   /xrt    /tdrss

With the /bat, /xrt, and /uvot directories beeing further subdivided into :

 /event /survey /pulsar /rate /hk /masktag /products   
 /event /image /hk /products   
 /event /image /hk /products

The 'tdrss' and 'trend' directory structure

The data under the sequences in the /tdrss or /trend main directories are not subdivided into directories and therefore data files are directly stored under each /tdrss sequence or /trend type.
As mention above, the sequence directory under the /tdrss main directory contains all the messages sent in response to a trigger. These include messages that result in a good trigger or messages related to false trigger. For false triggers the BAT collects it also contaThe tdrss For the BAT instrument the In addition includes

The messages related to the good triggers are also stored within the science data, /obs directory tree.

next up previous contents
Next: Data files Up: Swift Archive Guide Previous: Observation definition   Contents
Lorella Angelini 2007-04-03