USCG NAVIGATION CENTER NAVCEN and GPS CGSIC IISC European Meeting Prague, Czech Republic 14 March 2005 Rebecca M. Casswell Chief, GPS Branch
Dec 30, 2015
USCG NAVIGATION CENTER
NAVCEN and GPS
CGSIC IISC European Meeting
Prague, Czech Republic
14 March 2005
Rebecca M. Casswell
Chief, GPS Branch
Constellation Status
Interference Reporting
NAVCEN Mirror Site
U.S. NDGPS
Topics
Constellation SummarySince 1 Jan 04
•28 operational on-orbit satellites
• 3 satellites launched
–SVN59(PRN19): 20 Mar 04
–SVN60(PRN23): 23 Jun 04
–SVN61(PRN02): 6 Nov 04
• Next launch- May 2005
2 3 41
SVN (PRN)
2 3 41
Clock*Wheel
* II/IIA = Rb, Rb, Cs, Cs IIR = Rb, Rb, RbDiagonal Line = Unhealthy
launchdate Clock
meets specwatch list
deadunused
in use
Wheelfunctionalwatch listdead
GPS Space and ControlClock and Reaction Wheel
Performance Status(as of 22 Nov 2004)
39A (09) 06/93
25A (25) 02/92
1
2
SLOT
3
4
5
PLANE
A C D E F
38A (08) 11/97
56R (16) 1/03 36A (06) 03/94
33A (03) 03/96
59R (19) 03/04
46R (11) 10/99
17 (17) 12/89
51R (20) 05/00
40A (10) 07/96
26A (26) 07/92
43R (13) 07/97
24A (24) 07/91
41R (14) 11/00
44R (28) 07/00
27A (27) 09/92 35A (05) 08/93 37A (07) 05/93 34A (04) 10/93 54R (18) 01/01
32A (01) 11/92
15 (15) 10/90 29A (29) 12/92
45R (21) 03/03
6
47R (22) 12/03
31A (31) 03/93
30A (30) 9/96
B
60R (23) 06/04
61R (02) 11/04
7
GPS Positions 22 November 04
Block II
Block IIA
Block IIR
EPOCH 1 Jul 93
A CB ED F
0
40
80
120
160
200
240
280
320
Arg. of Latitude(deg)
Equator
E2
A3
A1
A2
A4
B3
B4
B2
B1
C1
C2
C3
C4
D1
D2
D3
D4
E1
E3
E4
F1
F2
F3F4
38
27
25
39
30
56
44
35
36
33
59
37
34
61
45
46
40
54
60
43
26
41
15
17
29
51
IIR-14
47
31
32
IIR-15
24
Constellation Performance
All Errors Based on Dual Frequency, Signal in Space Only. Information Presented Reflects Data Collected During the Period from January 1, 2004 to
August 31, 2004. Thresholds Provided Reflect Average Location Requirements from SPS Signal Specification Dated October, 2001.
PDOP Availability:• Requirement - PDOP of 6 or Less, 98% of the Time or Better• Actual - 99.98495%
Horizontal Service Availability• Requirement - 95% Threshold of 36 meters, 99% of the Time or Better• Actual – 2.75 meters
Vertical Service Availability• Requirement - 95% Threshold of 77 meters, 99% of the Time or Better• Actual – 3.98 meters
User Range Error• Requirement - 6 meters or Less, Constellation Average• Actual - 1.12 meters (excluding SVN23 anomaly, 1 Jan 04)
Data BroadcastsSubscription services that deliver Operational Advisory Broadcast
(GPS Status Messages) and/or the Notice Advisory to NAVSTAR Users (NANU) via List servers.
1. GPS Status List server: This service provides the subscriber with an e-mail containing the newly updated Status Message that is sent by the NAVCEN within 60 minutes of notification by the Air Force of a change to the GPS Constellation.
2. NANU List server: This service provides the subscriber with an e-mail containing the NANU that is sent by NAVCEN within 60 minutes of notification by the Air Force of a change to the GPS Constellation.
3. CGSIC List server: This service provides the subscriber with an e-mail containing GPS and CGSIC announcements.
Interference Reporting
The Navigation Center appreciates your reports regarding service degradations, outages, or other incidents or anomalies.
Please report problems via our GPS Problem Report Page
After a GPS user completes these forms, they are sent to a database for tracking, analysis, and resolution.
Reports may be received via phone/fax.
Interference Reporting Process User contacted for additional information, if necessary.
The report contains specific data regarding the observed outage, degradation, incident or anomaly.
If the report is aviation related it will be directed to the FAA for tracking, analysis, and resolution.
Maritime and terrestrial related reports will be simultaneously processed by the USCG GPS Liaison to the GPS Operations Center at Schriever AFB and NIS personnel for resolution.
USCG/USAF Resolution ProcessCheck for constellation events during reported outage period by
using NANU.
Check Post Assessment PDOP Charts at GPS Operations Center website.
Check DGPS logs for GPS signal anomalies (high pseudo range residual, high position error, high range rate correction, various types of dilution of position, high pseudo range noise) during reported outage times.
GSC Liaison checks for reports from military users during same time period of civilian report.
Perform analysis of constellation activity during reported outage times.
Interference Reporting Process
Upon finding a resolution, the NIS will notify the user; if the report is not resolved for 30 days, the user will be notified of the situation.
30 days after reporting findings to the user, the NIS will again contact the user to assess the situation and submit a new report if necessary.
Focus is on Customer Service and Satisfaction.
NAVCEN Web Site
NAVCEN Mirror Site
1. http://www.navcenter.org
2. Maintained to disseminate information for GPS, DGPS, and Loran radio navigation systems in the event our main site is unavailable.
3. Fully redundant information - all information and functions that are available on the primary site is available on the mirror site.
4. Hosted off-site with remote access capabilities.
DGPS
Current NDGPS Coverage
In the lower 48, approximately 87% has single coverage and
55% has dual coverage.
In the lower 48, approximately 87% has single coverage and
55% has dual coverage.
International Standard
NDGPS is designed to an international, non-proprietary standard Compliant with RTCM SC-104
and ITU-R M.823 Increases market for manufacturers Enhances Global interoperability
Signal is free to all users 47 other countries operate
systems compatible to ours Resulting in a seamless
international navigation system
Acceptance of the international standardAcceptance of the international standardis leading to a seamless worldwide service.is leading to a seamless worldwide service.Acceptance of the international standardAcceptance of the international standardis leading to a seamless worldwide service.is leading to a seamless worldwide service.
GPS (16-24 meters)
High Accuracy NDGPS
NDGPS(1 to 3 meters)
HA-NDGPSDynamic
(0.1 meters)
High Accuracy NDGPS Program Objectives
Develop a nationwide 3-D dynamic positioning service that has an accuracy of less than 15 centimeter and time to alarm integrity of less than 2 seconds
Coexist with existing NDGPS infrastructure
Do not degrade existing NDGPS
Minimize deployment costs
Navigation Information Service
http://www.navcen.uscg.gov
http://www.navcenter.org (mirror site)
E-mail: [email protected]
Phone: +1 703 313 5900
Fax: +1 703 313 5920