AIS Signal Loss
What Is AIS Signal Loss?
AIS signal loss is the apparent disappearance of a target, defined as the end of received or displayed reports from that vessel.
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AIS Signal Loss
A missing AIS target does not prove a vessel is hidden or gone. It may result from carriage gaps, permitted switch-offs, VHF range limits, or equipment faults. A graphical display shows a lost-target symbol at the last known position when reports cease.
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AIS Signal Loss
What Is AIS Signal Loss Used For?
AIS signal loss alerts operators that expected reports have stopped while the cause remains unknown. This status indicates a gap in data rather than a confirmed absence of the target.
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AIS Signal Loss
Why Does AIS Signal Loss Matter?
AIS signal loss matters because it creates a gap in situational awareness that cannot be interpreted as the vessel being absent or deliberately hidden. When reports from a target within a preset distance cease, a graphical AIS display may show a lost-target symbol at the latest reported position.
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AIS Signal Loss
How Is AIS Signal Loss Checked or Verified?
AIS signal loss is checked by verifying range limits, equipment status, and display symbols to confirm target disappearance. A graphical AIS display may show a lost-target symbol at the latest reported position when reports from a target within a preset distance are no longer received.
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AIS Signal Loss
How Does AIS Signal Loss Work?
AIS signal loss is a display gap from range, carriage, switch-off, malfunction or lost-target behaviour. Shipborne AIS works within VHF/FM range.
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AIS Signal Loss
What Are the Main Limitations of AIS Signal Loss?
A missing AIS target does not prove a vessel is hidden or gone. It may result from carriage gaps, permitted switch-offs, VHF range limits, or equipment faults. A graphical display shows a lost-target symbol at the last known position when reports cease.
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AIS Signal Loss
What Happens If AIS Signal Loss Is Unavailable or Wrong?
AIS signal loss means expected reports have stopped, requiring retained lookout and radar without treating absence as diagnosis. When a graphical display no longer receives reports from a target within a preset distance, it may show a lost-target symbol at the latest known position.
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