GRBP_DB_photonList.h File Reference

Schema defining the configuration parameters controlling a photon list. More...

Classes
struct	_GRBP_DB_photonList
	Configuration of the list holding the input photons. More...
Typedefs
typedef struct _GRBP_DB_photonList	GRBP_DB_photonList
	Typedef for struct _GRBP_gammaList.

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Detailed Description

Schema defining the configuration parameters controlling a photon list.

Author:

JJRussell - russell@slac.stanford.edu

   CVS $Id: GRBP_DB_photonList.h,v 1.1.1.1 2007/06/17 23:23:59 russell Exp $

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Typedef Documentation

GRBP_DB_photonList

Typedef for struct _GRBP_gammaList.

Typedef for struct _GRBP_photonList.

Photons that are believe candidates for a GRB are held in this list. In order to distinguish them from run-of-the-mill input photons they are called gammas. (There is no physics behind this naming, it is just a distinguishing name.)

These gammas are used to locate the GRB and from the basis for all the information stuffed into the alert messages. The description of a gamma is fairly small (32-64 bytes each) so making a list of ~10K of these is not unreasonable.

Photons received by the client (e.g. the SIU) from the servers (e.g. the EPUs), they are placed on a list. This list serves two purposes

1. Provide memory to hold the information about these photons that is used by the clustering code
2. Provide a history buffer that, once the clustering code determines a GRB has occurred, is searched for all photons that are near to the best computed location of the GRB The most important parameter (and currently the only one), is the maximum number of photons that the list will handle. Because it must provide the backing store for the photons in the clusters, the count must be at least as large as the cluster depth (

   See also:

   GRBP_clusterList). However, to be able reach back in time to photons that arrived before the GRB triggered, one should make this value larger. This value should cover whatever latency that one believes a GRB trigger will incur.

   The storage for each photon is relatively cheap (64 bytes or so), so that an upper limit ~10,000 (requiring 640K) is not unreasonable.