Satellite AIS for Dummies

In this course, you'll read texts about AIS and do tasks to reinforce your learning experience.

What is AIS?

Read: Satellite AIS for DUMMIES

Read: Satellite AIS for Dummies - The Introduction and Part 1

What does AIS stand for?

What is the name of the device that transmits signals?

What was AIS originally created for?

  • Monitoring vessels for security
  • Search and rescue
  • preventing ships from collision
  • tracking radio frequencies

Complete the sentence by filling in the blanks.

AIS devices send out information about the ship and regularly, typically every few .

TDMA

Each ship must have its own time to broadcast within. If they don’t, ships within close range of each other would constantly be competing for the same time slots when sending their reports, and the AIS messages would be because of the resulting interference.

How do the transmitters know where other transmitters are and which slots they are reserving next?

When slots collide . .

The ship that is will always have a signal, ensuring that the more important AIS message, from the closer ship, will be received correctly.

What are the two types of AIS devices?

The type A device must do the following:

  • Work with the ship’s radar
    and display systems
  • Have an integrated
    display
  • Transmit at
    12.5 watts
  • Be able to work with
    many of the ship’s systems
  • Offer advanced
    features and functions

The type B device must do the following:

  • Work with the ship’s radar
    and display systems
  • Have an integrated
    display
  • Transmit at
    5 watts
  • Be able to work with
    many of the ship’s systems
  • Offer advanced features
    and functions

AIS base stations

AIS base stations are (non-mobile) stations that maritime authorities use to and vessel traffic.

AIS base stations can also control other AIS devices, and have the following capabilities:

Turn other AIS on or off 

Reserve time for special transmissions

Control which time slots mobile AIS devices

Control the power level of AIS devices

Port authorities and coast guards ...

Port authorities and coast guards have a real interest in knowing about ship , so it’s not just the vessels that have gone into the AIS game. Many coastal AIS stations are being built to improve safety and for a country’s shoreline. These systems are expensive to build and maintain, but they allow authorities to monitor vast areas of shoreline that, prior to AIS, needed far more systems to monitor. In general, coastal AIS has a range of about nautical miles, but the coverage area can be shorter, depending on a few factors:

✓ Site of installation

✓ Height of the  

✓ Volume of in the area (which could lead to slot collision)

AIS Limitations

  • horizon
  • unlimited
  • 50
  • ship
  • Earth

What information does an AIS Message Contain?

  • Rate of turn
  • Ship name
  • Year Built
  • Historical Path
  • Position
  • Speed
  • Owner
  • Navigational Status
  • Destination
  • Estimated time of arrival (ETA)
  • Type of vessel
  • Number of port visits
  • Course
  • Size
Check the data that is sent in an AIS message.