VLBA RFI Bulletin 20: GPS Jamming Continues at WSMR in December: Scheduled testing of GPS jamming equipment will continue at the White Sands Missile Range during December, 1998. The GPS jamming tests are scheduled for Tuesdays, Thursdays, and Saturdays (except Thursday, 981231). Observers using the VLBA-PT and VLBA-LA receivers should expect an increased chance of RFI at the 2 GPS frequencies of 1575 MHz (L1) and 1228 MHz (L2) during the scheduled jamming times. The detailed schedule for November, 1998 follows: Tuesdays: 0701 UTC to 1100 UTC Thursdays: 0701 UTC to 1100 UTC (Except 981231) Thursday, 981231: None.