Monthly report for April 2000 by Christian A. Hummel:

Hummel attended the IAU 200 Symposium in Potsdam. He presented a poster
and participated in a panel discussion on new observing techniques.

Hummel incorporated comments he received from co-authors into the papers
on Omicron Leonis and Zeta Orionis, and submitted the latter to the
Editorial Board for review.

Hummel tested a combined group and phase fringe tracking algorithm based
on ideas discussed at the last quarterly meeting of NPOI, and showed that
the high frequency noise floor in atmospheric delay power spectra due to 
the precision of the fringe position determination could be significantly 
lowered.