VLBA RFI Bulletin 27: GPS Jamming Continues at WSMR in May: Scheduled testing of GPS jamming equipment will continue at the White Sands Missile Range during April, 1999. The GPS jamming tests are scheduled for Wednesdays, Fridays, and Sundays (UTC time). 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 May, 1999 follows: Wednesdays: 0200 UTC to 0600 UTC Fridays: 0200 UTC to 0600 UTC