### 99/06/24
   Due to the annual power line maintenance, no observations were
   available from June 24 0hUT until June 24 22:30 UT.
   After the power recovery, correlation values with W20 have been lower
   than normal.  W20 should be avoided in image synthesis for a while.
   We can see noises in the switched IF signals (Walsch switching).  This
   situation may continue until the next week.