1 uff file format – Guralp Systems Scream User Manual
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Scream! 4.5
Granularity : Allows you to decide how large files are allowed to
become before a new one is started, for three different types of stream
(high sample rates, low sample rates and status streams). The
distinction between high and low sample rates is set by the number in
the Sample Rates >= box; the remaining boxes give the number of
hours of data that Scream! should combine into a single file for each
type of stream. In the example above, streams with a sample rate of 20
samples/sec or above will be recorded in files with up to one hour of
data per file; lower-rate streams will be recorded in four-hour files,
whilst a new status file will be started every twelve hours. You will
need to choose a Filename format (see above) which gives each file a
unique name.
If you prefer to set a limit on a file's size, rather than its duration,
choose Kilobytes from the drop-down menu (instead of Hours or
Minutes) and set as appropriate.
Post-processor : This option allows you to specify a program which
Scream! will run every time it closes a file. The name of the file is
passed as a parameter. You can use this feature to interface to other
analysis or archival systems, for example:
•
you can use FTP or email to send files to remote data centres,
•
you can perform format conversion using a third party utility,
•
You can post-process file data headers to add site-specific
information.
9.2.1 UFF file format
Universal File Format (UFF) is a commonly-used interchange format
for seismic data. Two types of UFF format are supported: ASCII and
binary, where the extension ".ufa" denotes the ASCII variant, and ".ufb"
denotes the binary variant. The byte order used for the binary variant
is specified in the Recording pane of the Setup window. ASCII does
not have byte-ordering options. Details for the layout of the UFF
format can be obtained from the University of Cincinnati at
You can instruct Scream! to record incoming data directly in UFF
format. To do this, open the Files pane of the Setup window as above
and select either UFF ASCII (.ufa) or UFF Binary (.ufb) in the Data
format drop-down menu. However, UFF files tend to be large, and the
format does not retain the full resolution of the data gathered by the
sensor. It is recommended that you keep the initial recording in GCF
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