At the end of 1996 the output of the BDC reconstruction on the DST changed. Instead of writing the
reconstructed track banks on the DST, the raw information was added. That offers the possibility to
achieve a space reduction on the DST and to improve the BDC reconstruction and calibration based on
the full information.

Hence, the reconstruction of the BDC needs to be performed on the analysis level. Two possibilities
exist, either the BDC reconstruction module HDREC is called as a module before the analysis module
with all consequences of the module steering or an interface routine is called which does not provide
module steering.

How do you get reconstructed BDC quantities on the analysis level?

The BDC reconstruction is available within H1PHAN and recreates BDC reconstruction output
previously obtained from the DST. Since version 20308 of H1PHAN the BDC reconstruction can be
enabled by adding the bank QHDR to your steering file. Not only the DST banks but all banks created by
the BDC reconstruction module can be accessed in the QUEVT routine.

 In order to process the subroutine outside the H1PHAN framework the BDC reconstruction can be
performed by calling QHDREC in the event processing loop and linking the H1PHAN and H1REC8
library. The reconstruction still has to be enabled by switching the card HRON in the text bank QHDR.

In order to support analysis on the level of the BDC reconstruction output banks a few utilities are
available. The source code (bdc.cmz), a makefile and a steering file (bdc.card) is located on the WGS at
DESY in the directory ~marks/h1/bdc. The current installation is stamped with the version 1.00/00.

A few of the routines support filling of HBOOK ntuple blocks. The ntuple common blocks are (content)
actived by sequencing HBNAME calls via +SEQ,.... strings during the BEGJOB step. In case of an
H1PHAN process this is done in QUINIT and the code is supplied in the file bdc.cmz in the patch
PHAN_INTER.