Marine Communications Technology

GPS and Satellite Phone’s

What Is GPS?

A GPS is a Global Positioning System (GPS). It is a satellite-based navigation system made up of 24 satellites placed in space by the U.S. Department of Defense.

How Does A GPS Work?

GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. GPS receivers take this information and use triangulation to calculate the user's exact location.

http://www.youtube.com/watch?v=EOwMkFsJXRI

How Accurate Is GPS?

Today's GPS receivers are extremely accurate, thanks to their parallel multi-channel design. The parallel channel is quick to lock on satellites when first turned on and they maintain strong locks.

GPS Services

• GPS satellites provide service to civilian and military users. The civilian service is freely available to all users on a continuous, worldwide basis. The military service is available to U.S. and allied armed forces as well as approved Government agencies.

Jammers

• http://newyork.cbslocal.com/video?autoStart=true&topVideoCatNo=default&clipId=9183803

• This is a video on a man who do not wanting his company knowing where he is and so he used a jammer which interfered with a airport.

Facts

• There are always at least 24 active GPS satellites circling Earth, although today there are more than 30, including a couple of spares. Their orbits are spread out so that no matter where on Earth you are, you will have at least six of them in your line of sight.

• The first full constellation of 24 satellites was completed in 1994. The first of those 24 satellites was sent up in 1989.

Facts

• GPS isn’t just for navigation. It can also be used to get a very exact time stamp. Every GPS satellite has multiple atomic clocks and the time is included in the signal it sends out. With the help of these signals, a GPS receiver can determine the current time within 100 billionths of a second. These signals are for example used to synchronize base stations in cell phone networks.

Satellite Phone

What Are Satellite Phone’s

• Satellite phones are like mobile phones that connects to the satellites in space and you never lose service. they provide similar functionality to terrestrial mobile telephones service and low-bandwidth I access are supported through most systems.

How Do Satellite Phones Work

• Satellite phones must have "line-of-sight" to the satellites in order to operate. This means the antenna on the phone must be outdoors with nothing solid obstructing it's view to the sky. Anything solid can block the phone to satellite signal. e.g. Trees, buildings, hills or mountains, vehicles.

What Is The Coverage Area For The Iridium Satellite Phones

• The Iridium satellite phones are capable of making and receiving calls anywhere in the world, including the North and South poles and the oceans. The only exceptions will be those areas embargoed or restricted by the U.S. Department of State. Currently, these areas include: Cuba, Iran, North Korea, Sudan, & Syria

Is There An access Number To Reach The Iridium Satellite Phone

• Yes. There is an access number with a 480 area code. The caller will dial the access number and at the prompt, enter the 12-digit Iridium phone number they are trying to reach. The call will then be routed to the phone. Calls placed in this manner are called "Two-Stage Dialing," and there is a charge to the Iridium subscriber for this type of incoming call.

What Service Features Are Available On The Iridium Phones

• Voice mail, short messaging service. Call forwarding, call barring and Two-Stage dialing are all available on all Blue Cosmo Communications service plans. Voice mail is available on all plans, and call forwarding, call barring, SMS and Two-Stage dialing are included on all plans.

What Is Short Messaging Service

• The person trying to contact you on your Iridium satellite phone can send a short text message (under 160 characters) directly to your handset. There is no charge receive the SMS. Keep in mind that your handset must be on to receive the message, and the Iridium system only stores these messages for eight(8) days.

Is Emergency 911 Calling Available On The Iridium Network

• Yes, 911 Emergency service is available in North America only. You only need dial 911 to be connected to a central Emergency Services representative. No special prefixes or country codes are needed when dialing 911. When traveling outside North America it is advisable to have the emergency contact numbers with you.

What Is The Approximate Talk Time For The Batteries On The Satellite Phones

• Generally, the average talk time is 2-3 hours. This will vary based on battery type, battery age and phone model. We always advise carrying a spare, fully charged battery. The phones will also work without a battery, but while plugged in to an appropriate electrical source.