eGPS Network News

The following information is an accumulation of reports with their sources named. This information indicates that GPS operations should be normal for the next few days. Please call Lance or myself if you have any problems with our services.

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30 healthy GPS Satellites: (GPS/UTC offset is 15 seconds)

(NANU) 2009021 SVN49 (PRN01) WAS LAUNCHED JDAY 083 (24 Mar). NOT YET SET HEALTHY
(NANU) 2009025 SVN49 (PRN01) WILL BEGIN TRANSMITTING DATA-LESS L5 ON 10 APRIL NO EARLIER THAN 1000UTC
(NANU) 2009130 SVN25 (PRN25) UNUSABLE JDAY 352(18Dec)/1522-UNTIL FURTHER NOTICE
(NANU) 2010009 SVN34 (PRN04) FORECAST OUTAGE JDAY 026(26Jan)/1400 - JDAY 027/0200
(NANU) 2010010 SVN48 (PRN07) FORECAST OUTAGE JDAY 028(28Jan)/0530 - JDAY 028/1730


The L1/L2 transmitters of SVN49 (PRN01) were activated on 28 March.

However, the satellite has not yet been declared healthy and is not yet included in almanacs.

Signal distortions have been observed from the satellite; however it is expected be introduced into the operational constellation sometime.


Mission planning is strongly encouraged for your GPS operations as even with 30 satellites there remain some periods of high DOP and reduced availability in some regions when using an elevation mask of 10 degrees or higher. You can have high DOP even with 6 satellites if the geometry is poor.

ftp://ftp.trimble.com/pub/eph/almanac.alm
<ftp://ftp.trimble.com/pub/eph/almanac.alm>  (Latest combined GPS/GLONASS
Almanac)

http://www.navcen.uscg.gov/gps/almanacs.htm
<http://www.navcen.uscg.gov/gps/almanacs.htm>
<http://www.navcen.uscg.gov/gps/nanu.htm> (YUMA GPS only Almanac from USCG
NAVCEN)

http://www.trimble.com/planningsoftware_ts.asp
<outbind://44-00000000D6F2DA66D9985741BD601B65A256D2A8648E2B00/exchweb/bin/r
edir.asp?URL=http://www.trimble.com/planningsoftware_ts.asp>  (Free Trimble GPS/GLONASS planning software)

Note:  Always download and use the latest almanac for mission planning.
Otherwise you must explicitly set satellites unhealthy/healthy as necessary to evaluate your specific constellation scenario. Always verify age of downloaded Almanac to be sure it is current.
<http://gps.afspc.af.mil/gpsoc/PerformanceReportsImageViewer.aspx?ReportID=1
883


GPS Launch Update:

GPS Block IIR-20 (SVN49) was launched 24 March 2009. It is not yet set healthy.

The next generation GPS IIF-1 (SVN62) is provisionally scheduled for launch May 2010.


GPS Update:

The US Government Accountability Office has issued a report highlighting concerns in maintaining the current GPS service without interruption.

See the full report at the following link:
http://gao.gov/products/GAO-09-670T <http://gao.gov/products/GAO-09-670T>


GPS Interference Testing:  No update available 22 Jan 2010

Specific times/dates are listed at:
http://www.navcen.uscg.gov/gps/gpsnotices/GPS_Interference.pdf
<http://www.navcen.uscg.gov/gps/gpsnotices/GPS_Interference.pdf

CONUS WAAS GEO (correction source) Satellite Status:


WAAS PRN's 135 and 138 are now operational. WAAS PRNs 122 and 134 have both been removed from service.

Reference:
http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/t
echops/navservices/gnss/waas/news/
<http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/
techops/navservices/gnss/waas/news/
>

GLONASS Status: (22 January 2010)

17 (of 22) Satellites healthy

GLONASS 701:  slot/RF-chnl 6/-4 Decommissioning

GLONASS 726:  slot/RF-chnl 22/-3 Maintenance

GLONASS 713:  slot/RF-chnl 24/02 Decommissioning

GLONASS 730:  slot/RF-chnl 1/01 Commissioning

GLONASS 733:  slot/RF-chnl 4/06 Commissioning


Note: GLONASS 722:  slot/RF-chnl 9/-2 operates on L1 only.


GLONASS Update:

11.01.2010 On January 10, 2010 the "Glonass-M-734" spacecraft of Block-41 is included into the operational constellation in orbital slot 5. According to the System Control Center the work on Block-41's spacecraft 730 and 733 commissioning is being conducted nominally as per schedule.


The next launch which was due in December is now expected in the 11-20 February 2010 time frame.


EGNOS/Galileo Update:

Brussels, 7 January 2010Heading4

Commission awards major contracts to make Galileo operational early 2014

The European Commission announced today the award of three of the six contracts for the procurement of Galileo's initial operational capability.
The contract for the system support services is awarded to ThalesAleniaSpace of Italy , that for a first order of 14 satellites to OHB System AG of Germany and that for the launch services to Arianespace of France. This will allow the initial deployment and service provision of Europe's satellite navigation system as of early 2014.

Antonio Tajani, European Commission Vice-President in charge of Transport,
said: "With this and the upcoming awards for the remaining procurement packages, we are concluding a critical phase of the Galileo programme. We can now focus on the actual roll-out and demonstrate to European citizens that Europe's own satellite navigation system is firmly underway".

For the complete article see the following link:

http://europa.eu/rapid/pressReleasesAction.do?reference=IP/10/7
<http://europa.eu/rapid/pressReleasesAction.do?reference=IP/10/7&language=en
> &language=en


3-Day Report of Solar & Geophysical Activity: (Updated 21 January 2010
2201UTC)


Solar Activity Forecast: Solar activity is expected to be at very low to low levels with a chance for M-class flare activity.

Geophysical Activity Forecast: The geomagnetic field is expected to remain at quiet levels for the next three days (22-24 January).

Current Space Weather Conditions:                            

Solar wind speed 385 km/sec;
Updated 22 January 2010@1326UTC

17 sunspots;
Updated 21 January 2010                                              

Sunspots on the far side;
No update available       

F10.7 cm Radio Flux(Penticton), 81;
Updated 21 January 2010@22:00UTC

Planetary K-index (Maximum during preceding 24 hours), Kp = 4:  Updated 22 January 2010@1346UTC

Planetary A-index (Est. 24hr running value), Ap = 2;
Updated 22 January 2010@1348UTC      

IMF is South (Bz= 1.2 nT);
Updated 22 January 2010@1336UTC      

Kp index: Maximum value of previous four, 3-hourly planetary index measurements of geomagnetic activity

Ap Index: A measure of the general level of geomagnetic activity over the globe for a given (UT) day.

IMF: Interplanetary Magnetic Field: When the interplanetary magnetic field turns south compared to the Earth's magnetic field, geomagnetic activity will increase. As the Bz (Southward pointed) value becomes more negative, the associated geomagnetic activity increases.


Solar Cycle Update:


The Solar Cycle 24 Prediction Panel has agreed that the solar minimum occurred in December 2008.

The predicted solar maximum (Cycle 24) is now expected to occur in May 2013.

See the following link for more details:

http://www.swpc.noaa.gov/SolarCycle/ <http://www.swpc.noaa.gov/SolarCycle/>