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GPS OPERATIONAL REQUIREMENTS DOCUMENT (ORD)

The U.S. Department of Transportation is identifying operational requirements for input to the design of the next generation of GPS satellites. The following table contains design parameters followed by three columns.

The first column is labeled SORD and contains the current requirement. A blank space in that column indicates that a value was not previously identified.

The second column is labeled THRESHOLD and contains the minimum acceptable value. This is the lowest requirement for input to an augmentation system.

The third column is labeled OBJECTIVE and contains the value that your application requires. Whether this requirement is met by GPS only or still requires augmentation will be decided at a later date.

If you requirement is more stringent than what is presented in the table or you can identify an additional parameter, please send your requirement with justification to the Navigation Center. To submit addition requirements or to obtain additional information contact Rebecca Casswell, Bulletin Board User-id: PPSPO, FAX- (703)313-5805 or voice at (703)313-5930.

PARAMETER SORD ORD

THRESHOLD

ORD

OBJECTIVE

POSITION, VELOCITY AND TIMING ACCURACY      
PPS POSITION ACCURACY 16m SEP £10m SEP 1m SEP
SPS ACCURACY (DOT) 100m 2drms 100m 2drms no effect from SA
PPS VELOCITY classified classified 0.01 m/sec
TIMING (from UTC) PPS 100 nsec

(1 sigma)

20 nsec

(1 sigma)

10 nsec (1 signal)
SERVICE AVAILABILITY 0.98 0.98 99.999% (DOT)
COVERAGE 0.98 0.98 0.999
SERVICE RELIABILITY RE-LOOK, INTEGRITY?    
FIX RATE continuous 1 Hz 5 Hz
FIX DIMENSION   3DPVT + Time Sync 3DPVT + Time Sync
SYSTEM CAPACITY   unlimited unlimited
GEODETIC DATUM/ELLIPSOID   WGS-84, ability

to operate with any regional datums

WGS-84, ability to

operate with any

regional datums

SECURITY AND SURVIVABILITY      
JAMMING   classified classified
SPOOFING   classified classified
PPS SIGNAL DENIAL   Operate in natural space environment Operate in natural space environment.

Operate through a

multiple collateral

threat.

(insert size of threat)

ELECTRONIC KEY CAPABILITY   New add-in New add-in
SYSTEM SECURITY   New add-in New add-in
SYSTEM SURVIVABILITY   New add-in New add-in
TIMING SPS 300 nsec

(1 sigma)

   
OPERABILITY & SUSTAINABILITY      
LAUNCH CALL-UP TO PAYLOAD

OPERATIONAL

  AFSPC issue AFSPC issue
MEAN MISSION DURATION   AFSPC issue AFSPC issue
ADDITIONAL PAYLOADS SUPPORTED   AFSPC issue AFSPC issue
SATELLITE COMMAND AND CONTROL   AFSPC issue AFSPC issue
NUMBER OF SIMULTANEOUS

SATELLITE CONTACTS

  AFSPC issue AFSPC issue
NUMBER OF SATELLITES (ON-ORBIT) CONTROL SEGMENT CAN

SUPPORT

  AFSPC issue AFSPC issue
OCS MISSION EFFECTIVENESS   AFSPC issue AFSPC issue
BACKUP COMMAND AND CONTROL SYSTEM   AFSPC issue AFSPC issue
OPERATIONAL ENVIRONMENT   New add-in New add-in