International Gravitational
Event Collaboration
The undersigned gravitational wave detector
groups who are currently operating gravitational wave detectors, agree to set
up a data exchange protocol called the International Gravitational Event
Collaboration, for coordinating and correlating the data from the detectors. It
is based on some technical and policy rules for data exchange and provides the
constituition of one or more facilities, open to the members with rules to be
established, to maintain a data-base and a news group.
The following sets out the principles of
the protocol. The details will be defined and updated according to experience
and the changes in computer technology.
1 - Technical points:
-
Each group will set up a site (ftp, www by
password, telnet, ...) on which data will be continually available in agreed
formats and normally with an updating rate close to the real-time and not
exceeding one day.
-
The data will consist of ”candidate events” and
service information such as parameters of the antenna, start run and stop run
times, hourly statistics of the noise and descriptions of the apparatus and of
the filters used for data processing.
-
A news group is to be maintained to allow
planning and coordination of detector maintenance and downtime. LSU volunteers
to set this up.
-
The groups will work towards automatic analysis
which will, in the case of very rare coincidence events, produce an automatic
mail alert.
2 - Physical points:
-
For each operating antenna the individual group will
select, with a threshold matched to the noise of the detector of order 100
events per day. The technique to produce the events will be chosen by the
individual group on the basis of their experience and the type of noise of
their detector.
-
The groups are committed to set up procedures to
reduce spurious candidate events.
-
The groups will describe, post and update the
procedures used to reduce spurious candidates.
-
The minimum information about each event consists
of - the time (in UT) of the event maximum – the amplitude in units of
”standard burst strain” - the duration of the event - the mean noise of the
detector at the time of the event in units of h.
-
Additional fields, giving further information on
candidate events, may be provided at the individual groups discretion. For
instance if any group uses more filters on the data, it will be possible to
post additional event lists from these filters.
-
The time accuracy will be at least 0.1 seconds
and the groups will perform procedures to check this and will give information
in case of larger errors.
-
The exchange of raw or filtered sampled data will
be considered in the future.
3 - Policy points:
-
The goal of the IGEC is to standardize and
simplify the data exchange between the groups and to mantain a continous
discussion on the data and the analysis procedures. The members of this center
are committed to not make public results based on this data exchange without
unanimous agreement of all members.
-
The core membership of the center consists of
groups producing gravitational wave data. Membership can also be given to
groups for data analysis purposes.
-
Members will be added or dropped by unanimous
agreement of the core members.
-
The data of the collaboration will become public
after a certain period to be established.
Signed:
William Hamilton (LSU)
Warren Johnson (LSU)
Guido
Pizzella (Rome)
Giovanni
V. Pallottino (Rome)
David
Blair (UWA)
Mike
Tobar (UWA)
Massimo
Cerdonio (Padova)
Stefano
Vitale
4
July 1997 at the 2nd Amaldi Conference