Discrepancy Reports

DR#	Date of Occurrence GPS Week/Day(s)	Documents
1	W1321 D4 (5/5/2005)	DR 1 ZLA C&V Failure
2	W1321 D6 (5/7/2005)	DR 2 type 6
3	W1322 D0 (5/8/2005)	DR 3 Iono Storm May 8 2005
4	W1322 D1 (5/9/2005)	DR 4 SV 2 outage May 9 2005
5	W1322 D2 (5/10/2005)	DR 5 SV 6 outage May 10 2005
6	W1323 D0 (5/15/2005)	DR 6 SV 27 DNU update
7	W1326 D0 (6/5/2005)	DR 7 - IGP 95W40N
8	W1327 D(s)0,1 (6/12,13/2005)	DR 8 Iono Storm June 12 2005
9	W1328 D2 (6/21/2005)	DR 9 TTA failure and type 6
10	W1329 D0 (6/26/2005)	DR 10 POR SIS Outage
11	W1330 D0 (7/3/2005)	DR 11 two IGPs in storm state
12	W1330 D6 (7/9/2005)	DR 12 UPM trip at Juneau causes NPA outage in the POR service area
13	N/A
14	W1334 D1 (8/1/2005)	DR 14 Availability loss due to UDRE increase in PRN 14
15	W1336 D0 (8/14/2005)	DR 15 garbled message - not monitored
16	W1338 D0 (8/28/2005)	DR 16 POR service outage after GUS switch
17	W1338 D3 (8/31/2005)	DR 17 WAAS service outage after GUS switch
18	W1340 D1 (9/12/2005)	DR 18 Miami Thread 3 WAAS G2 Receiver (CRR) sending WAAS navigation message with incorrect time received
19	W1338 D1 (8/29/2005) W1338 D4 (9/1/2005) W1339 D1 (9/5/2005)	DR 19 Inaccurate GPS satellite measurements from Houston and Chicago G2 rcvrs
20	W1341 D1 (9/19/2005)	DR 20 - SIS Outage OD race condition
21	N/A
22	W1351 D6 (12/3/2005)	DR 22 POR Message Gaps caused TTA Monitor Trip & Loss of PA&NPA Service
23	W1351 D4 (12/1/2005)	DR 23 High numbers of SV alerts in both AORW and POR
24	W1359 D1 (1/23/2006)	DR 24 Multiple POR Geo gaps after 2 POR GUS switchovers
25	W1363 D3 (2/22/2006)	DR 25 Extended POR Signal-in-Space Outage after Communication failure
26	W1362 D4 (2/16/2006)	DR 26 Near-Simultaneous GUS Failures Caused AOR-W SIS Outage
27	W1376 D0 (5/23/2006)	DR 27 IGPs around Hawaii set to Do Not Use
28	W1364 D5 (3/3/2006) W1365 D(s)0,1,2 (3/5,6,7/2006)	DR 28 ZDC C&V Faulted Repeatedly
29	W1360 D4 (2/2/2006)	DR 29 Localized Loss of Availability Over Central CONUS
30	W1361 D4 (2/9/2006)	DR 30 Loss of Availability due to Satellite Maintenance, SV 5 (NANU 2006013)
31	W1365 D6 (3/11/2006)	DR 31 Loss of Availability due to Extended Satellite Maintenance on SV 30 (NANU 2006020)
32	W1367 D3 (3/22/2006)	DR 32 Loss of Availability Due to Extended Signal-in-Space (SIS) Outage
33	W1376 D5 (5/26/2006)	DR 33 Loss of Service, SV 13, NANU 2006047
34	W1377 D2 (5/30/2006)	DR 34 Clarksburg GUS Failure
35	W1376 D4 (5/25/2006)	DR 35 Extended AORW Signal-in-Space Outage after equipment failure
36	W1379 D6 (6/17/2006) W1380 D(s)0-1 (6/18-19/2006)	DR 36 AORW SNR Drops
37	W1380 D6 (6/24/2006)	DR 37 C&V failure at ZDC and ZLA
38	W1383 D0 (7/9/2006)	DR 38 False RDM & UPM monitor at ZDC C&V
39	W1369 D1 (10/9/2006)	DR 39 AOR-W switchover and extended SIS outage
40	W1400 D0 (11/5/2006)	DR 40 Type 0 Messages After C&V Faults
41	W1398 D4 (10/26/2006)	DR 41 WAAS Ionospheric Grid Points (IGP) set to Do Not Use
42	W1400 D(s)2-6 (11/7-12/2006) W1401 D1 (11/13/2006)	DR 42 - SV 5 outage , NANU 2006145
43	W1403 D3 (11/29/2006)	DR 43 Switchover followed by Signal-in-Space (SIS) outage in CRW
44	W1404 D0 (12/3/2006)	DR 44 Signal-in-Space (SIS) outage in CRW
45	W1403 D5 (12/1/2006)	DR 45 AOR-W switchover and extended SIS outage
46	W1404 D1 (12/4/2006)	DR 46 4 seconds initialization in AORW, POR and CRW
47	W1399 D0 (10/29/2006)	DR 47 Iono Scintillation at Fairbanks
48	W1412 D5 (2/2/2007)	DR 48 CRW Switchover and Extended SIS Outage
49	W1416 D3 (2/28/2007)	DR 49 GUS Switchover in CRW caused by Serial Port and M&C Communication failure
50	W1408 D3 (1/3/2007)	DR 50 Loss of Northwest coverage due to 3 satellites being set to Not Monitored
51	W1419 D6 (3/24/2007)	DR51 Loss of LPV service area in Alaska due to IGP GIVE set to 15
52	W1420 D5 (3/30/2007)	DR 52 Ionospheric Scintillation caused High Position Errors at Fairbanks
53	W1419 D6 (3/24/2007)	DR 53 Iono Scintillation at Juneau
54	W1421 D0 (4/1/2007)	DR 54 POR SV Alert Did Not Change UDREI's
55	W1422 D2-3 (4/10-11/2007)	DR 55 GPS satellite PRN 18 anomaly affecting SPS performance
56	W1421 D4 W1425 D5 (4/5/2007 5/4/2007)	DR 56 Loss of 100 percent WAAS availability in southwest CONUS region
57	W1424 D4 (4/26/2007)	DR 57 Inconsistent satellite tracking of PRN 25 at non-G2 WAAS receivers following NANU 2007060
58	W1426 D3 (5/9/2007)	DR 58 Communication fault caused selected C&V source switch on CRW GUS
59	W1430 D6 (6/9/2007)	DR 59 POR GEO pointing error caused SIS degradation and outage
60	W1432 D4 (6/21/2007	DR 60 ZDC C&V fault followed by GEO initialization
61	W1433 D4 (6/28/2007)	DR 61 ZDC C&V fault followed by GEO initialization
62	W1421 D1 (4/2/2007)	DR 62 Ionospheric scintillation that caused high errors and alarm condition (Report is pending)
63	W1438 D2 (7/31/2007)	DR 63 WAAS set all satellite and IGP's to Not Monitored (Report is pending)
64	W1458 D3 (12/19/2007)	DR 64 SV PRN 27 Unexpectedly Set to Not Monitored (Report is pending)
65	W1448 D1 (10/8/2007)	DR 65 Three Unforcasted GPS Satellite Outages Caused Reduced Ranging Availability
66	W1448 D1 W1448 D3 (10/8/2007 to 10/10/2007)	DR 66 WAAS Observations of GPS AEP Upload to IIRM Satellites
67	W1468 D4 (2/28/2008)	DR 67 GIVE Monitor Trips Set IGPs to Storm State in Alaska Region
68	W1473 D3 (4/2/2008)	DR 68 Satellite Outages Caused Loss of Availability in CONUS Region
69	W1467 D0 (2/17/08)	DR 69 Alaska Communications Outage Caused Loss of Alaska LPV Service (Report is pending)
70	W1470 D3 (3/12/08)	DR 70 Selected C&V Source Switch Followed By Geo Initialization Caused Loss of LPV and NPA Service (Report is pending)
71	W1472 D5 (3/28/08)	DR 71 Inconsistent Tracking of SV PRN 10 Following NANU 2008036 Caused Elevated UDRE's (Report is pending)
72	W1483 D0 - W1483 D1 (6/8/08 to 6/9/08)	DR 72 Loss of Availability in Alaska Due to Satellite Maintenance (Report is pending)
73	W1494 D6 (8/30/08)	DR 73 CRW High L5 C_N0 and GUS Switchovers (Report is pending)
74	W1495 D0 (8/31/08)	DR 74 CRW 32 min SIS Outage (Report is pending)
75	W1498 D6 (9/27/08)	DR 75 C&V Initialization Caused WAAS Service Outage
76	W1500 D1 - W1500 D1 (10/5/08) - (10/6/08)	DR 76 False trip on PRN 24 with minimal effect on WAAS Coverage
77	W1503 D3 - W1509 D9 (10/5/08) - (10/6/08)	DR 77 CRW Downlink Frequency Spikes Caused Reduced PA Ranging Availability
78	W1525 D0 (3/29/09)	DR 78 False WAAS satellite alert for PRN 29
79	W515 D6 (1/24/09)	DR 79 Doppler Spike caused CRW Signal In Space Outage
80	W1520 D5 (2/27/09)	DR 80 Ionospheric Scintillation caused High Position Error at Fairbanks and Kotzebue
81	W1532 D4 (5/21/09)	DR 81 CRW Type 6 Message set Mutiple Satellites to NM (Report is pending)
82	W1544 D1 (8/13/09)	DR 82 ZDC CNV Faults Upon Receipt of QWE Garbled Message
83	W1544D2 W1545D6 (8/11/09 8/22/09)	DR 83 ZTL Bad Orbit Determination for PRN135
84	W1549D4 W1549D5 (9/17/09 9/18/09)	DR 84 Reduced Precision Approach GEO Ranging Caused WAAS Coverage Loss
85	W1549D5 (9/18/09)	DR 85 PRN 23 NANU Affects WAAS Coverage
86	W1542 D0 W1543 D5 (7/26/09) (8/7/09)	DR 86 SVN 54 PRN 18 Signal Distortion
87	W1553D5 W1555D1 (10/16/09 10/26/09)	DR 87 PRN 8 NANU Affects WAAS Coverage
88	W1531D1 (5/11/09)	DR 88 Effect of CRW UDREi changes on Alaska LPV200 Coverage
89	W1568D2 (1/26/10)	DR 89 PRN 4 NANU Affects WAAS Coverage
90	W1569D6 (2/6/10)	DR 90 Extended SIS Outage on CRW
91	W1575D4 W1577D3 (03/18/10 03/31/10)	DR91 CRE Broadcast UDRE Not Monitored for CRW after C&V Fault
93	W1578D1 (4/5/10)	DR 93 Ionospheric Storm Caused Alaska Coverage Drop
94	W1581D2 (4/27/10)	DR 94 PRN 17 NANU Affects WAAS Coverage
95	W1584D5 (5/21/10)	DR 95 PRN 16 and PRN 32 Unplanned Outages
96	W1582D5 (5/7/10)	DR 96 PRN138 Geo Stream Caused Increased Position Errors and Ratios
97	W1599D1 (8/30/10)	DR 97 Large number of not monitored alarms on PRN25
98	W1611D3 (11/24/10)	DR 98 WAAS LPV200 Service Outage at Washington DC WRE-A caused by L1 Radio Frequency Interference (RFI)
99	W1606D0 (10/17/2010)	DR 99 Boston LPV outage caused by RFI
100	W1623D4 (2/17/2011)	DR 100 Kansas City signal drop caused by RFI
101	W1625D4 (3/3/2011)	DR 101 Elevated UDREs on several satellites cause LPV200 coverage drop
102	W1639D0 (6/5/2011)	DR 102 WAAS Reaction to Iono Activity June 5 2011
103	W1647D5-W1647D6 (8/5/11 8/6/11)	DR 103 WAAS Reaction to Iono Activity August 5-6 2011
104	W1655D1 (9/26/11)	DR 104 WAAS Reaction To Iono Activity September 26 2011
105	W1658D5 (10/21/11)	DR 105 Software Upgrade 3A C&V Failure
106	W1660D4 W1664D3 (11/3/11 11/30/11)	DR 106 UDRE Spikes Lead to Reduced WAAS Availability
107	W1665D2 W1669D5 (12/6/11 1/6/12)	DR 107 CRW Oscillator Failure
108	W1667D1 (12/19/11)	DR 108 L2 Interference at Honolulu
109	W1693D0 (7/17/12)	DR 109 PRN 19 Ephemeris Update Triggered RAIM FDE to Exclude SV from Nav
110	W1695D4 W17-1D5 (7/5/12 8/17/12)	DR 110 PRN4 Carrier Phase Anomalies Cause WAAS SV Alerts
111	W1709D2 (10/09/12)	DR 111 Vertical Position Errors Increased at Fairbanks due to Ionospheric Scintillation
112	W1711D6 W1712D5 (10/09/12 11/02/12)	DR 112 RFI at Iqaluit caused Loss of Satellite Tracking
113	W1733D6 (3/29/13)	DR 113 Ionospheric Scintillation Causes Elevated Vertical Errors at Higher Latitude WAAS Reference Stations
114	W1740D3 (5/15/13)	DR 114 LPV Service Outage Due to Consecutive SV Alerts on PRN 138
115	W1742D6 (6/1/13)	DR 115 Effect on WAAS from Iono Activity on 01JUNE2013
116	W1768D2 (11/26/13)	DR 116 Fewer Reference Stations Than Expected Tracked PRN 1 Following Satellite Maintenance
117	W1769D3 W1778D0 (12/4/13 2/2/14)	DR 117 Excessive Not Monitored Alarms on PRN 1_SVN 63
118	W1764D4 W1765D1 (10/31/13 11/4/13)	DR 118 PRN2 Anomaly
119	W1783D3 (3/12/14)	DR 119 Geomagnetic Activity and Common WRS Communication Outages
120	W1784D5 (3/21/14)	DR 120 PRN25 Illegal IODE IODC
121	W1782D5 (3/7/14)	DR 121 PRN17 NANU and SV Alert on PRN 25 Affects WAAS Coverage
122	W1783D1 (3/10/14)	DR 122 PRN4 and PRN20 DNU due to Iono at Equator
123	W1787D5 W1787D6 (04/11/14 04/12/14)	DR 123 Effect on WAAS from Iono Activity April 11-12 2014
124	W1797D3 (6/18/14)	DR 124 Loss of LPV-200 Service in Central CONUS June 18 2014
125	W1809D5 W1809D6 (9/12/14 9/13/14)	DR 125 Effect on WAAS from Iono Activity September 12-13 2014
126	W1826D3 (1/7/15)	DR 126 Effect on WAAS from Iono Activity January 7 2015
127	W1836D2 W1836D3 (03/17/15 03/18/15)	DR 127 Effect on WAAS from Iono Activity March 17 2015
128	W1861D3 (9/9/15)	DR 128 Effect on WAAS from Iono Activity September 9 2015
129	W1867D2 (10/20/15)	DR 129 WAAS set PRN 23 set to Not Monitored Following the Conclusion of NANU 2015086
130	W1887D0 W1887D1 (03/06/16 03/07/16)	DR 130 Ionospheric Activity Effects on WAAS Performance 6-7March 2016
131	W1887D2 (03/08/16)	DR 131 Elevated Correlation Peak Distortion Observed Starting 3/8/16
132	W1914D5 W1914D6 (9/16/16 9/17/16)	DR132 WAAS set PRN14 to Not Monitored Following the Conclusion of NANU 2016063
133	W1916D3 (9/28/16)	DR133 Ionospheric Grid Points (IGPs) values set not monitored in North East service area caused 12 miin LPV200 outage in Canada
134	W1918D6 (10/15/16)	DR 134 GPS satellite PRN25 ephemeris broadcast reused IODE (equal to 98) within 30 minutes
135	W1933D3 W1936D0 (01/25/17 02/12/17)	DR 135 FAA Tech Ctr Observations of GPS Increased L1 C_A Power Testes 25JAN to 12FEB 2017
136	W1930D3 (01/04/17)	DR 136 PRN 138 Propellant Lines caused several maneuver aborts causing Do Not Use conditions on CRE.
137	W1938D4 W1943D2 (03/02/17 04/04/17)	DR 137 UDREi bumps to Not Monitored due to loss of L2 Tracking
138	W1945D6 W1946D1 (04/22/17 04/24/17)	DR 138 UDREi Spikes to Not Monitored Observed on PRN6
139	W1951D3 (5/31/17)	DR 139 WAAS User Messages Lost After Faulted GUS Switch
140	(10/17)	DR 140 NOTAM For GPS Testing
141	W1985D2 (1/23/18)	DR 141 PRN 18 NANU
142	W1975D2 (11/14/17)	DR 142 False Tracking