AvMap ekp iii c ユーザーズマニュアル

corrected data. Care must be taken to ensure that the DGPS receiver and the GPS receiver are

compatible for this procedure to be successful.

The Global Positioning System is monitored and controlled by the U.S. Air Force, which is

responsible for updating and maintaining exact satellite position and signal data accuracy. It is

also responsible for performing maintenance on the satellites, which may require the satellite

being taken off-line. Since the system is subject to periodic updates and changes, the almanac

data broadcast by the satellites is current for a limited time — generally about 14 days.

The needs of the worldwide civil GPS user community are served by the Civil GPS Information

Center (GPSIC) in Virginia. The GPSIC is operated and maintained by the U.S. Coast Guard for

the U.S. Department of Transportation. Its primary function is to provide information on the

Global Positioning System and satellite status and to serve as a point of contact.

The GPSIC has general GPS literature available free upon request. The Center also

maintains up-to-date almanac data and Operational Advisory Broadcasts containing current

constellation status and planned satellite outages.

There are three ways to quickly obtain current information about the Global

Positioning System from the GPSIC:

1. Recorded phone message at (703) 313-5907

2. WebSite: www.navcen.uscg.mil

3. Live information at phone (703) 313-5900

There are several GPS bulletin board services outside the United States, including:

+27 (12) 803 8318

+49 (69) 6333 418 Internet via TELNET: 141.74.240.25

German X.25 Network, Datex-P (from Sprintnet preferred):

45050262720

+47 32124045 or +47 32118369

United Kingdom +44 (602) 422111 full access is available only to members of the UK

Civil Satnav Group

There are other sources for GPS information, ranging from free, governmentally pro-

duced literature to purchased professional literature and seminars. The geography department

of your local college or the local office of the National Geodetic Survey may be able to help.

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EKP III USER MANUAL