While intended mainly for pilots I thought I'd repost this here since a number of folks here use GPS and it looks like the effects of the test could reach the ground. patrick http://download.aopa.org/epilot/2011/110426utah.pdf FEDERAL AVIATION ADMINISTRATION FLIGHT ADVISORY GPS Testing ACC GPS 11-07 April 28, 2011 – May 13, 2011 Wendover, UT GPS testing scheduled as follows may result in unreliable or unavailable GPS signal. A. Location: Centered at 402602N/1132936W or the BVL VOR 145.44 degree radial at 21.3NM. B. Datesandtimes: 28 APR – 29 APR 30 APR - 06 MAY 09 MAY – 13 MAY 1700Z – 2000Z 2200Z – 0000Z 1700Z – 2000Z 1700Z – 2000Z C. Duration: Tests will be conducted continuously during times requested above. D. During testing, the GPS signal may be unreliable or unavailable within a 395NMR centered at 402602N/1132936W or the BVL VOR 145.44 degree radial at 21.3NM at FL400 and above, decreasing in area with decrease in altitude to 355NMR at FL250, 260NMR at 10,000 FT MSL, 265NMR at 4,000 FT AGL and 225NMR at 50 FT AGL. E. Pilots are strongly encouraged to report anomalies during testing to the appropriate ARTCC to assist in the determination of the extent of GPS degradation during tests. The NOTAMs discussed in this advisory may change with little or no notice. Pilots are advised to check NOTAMs frequently for possible changes prior to operations in the area. NOTAMs will be published at least 24 hours in advance of any GPS tests.