ECDIS FINAL EXAM QUESTIONS AND
ANSWERS 100% PASS
Class A AIS - ANS Uses a reservation-based transmission system, which ensures transmission
will take place.
Class B AIS - ANS Searches for unused transmission time slots to make transmission and may
not transmit a signal if a large number of AIS systems are in the area.
AIS Range - ANS Line of sight around 20nm but may be higher (99nm) due to ducting.
Components of AIS - ANS 2 VHF Radio Frequencies.
Static Data in AIS - ANS Entered into the AIS installation and need only be changed if the ship
changes its name or undergoes a major conversion from one ship type to another.
Voyage Data in AIS - ANS Manually entered and updated during the voyage; usually does not
change over the course of the voyage.
Dynamic Data in AIS - ANS Information which could change rapidly or would want a quick
update if it changed; most are automatically updated from ship sensors.
Safety Messages - ANS Text alert sent via AIS.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Doppler Satellite Navigation Systems - ANS The first system for satellite navigation and
provides latitude and longitude from one satellite.
US System of Satellite Navigation - ANS SATNAV (Navy Navigation Satellite System), turned off
by the US government in 1996.
Russian System of Satellite Navigation - ANS Leo SATNAV, with Parus as the civilian system
and Tsikada-M as the military system.
Frequency of Obtaining Fixes - ANS This system can only take a few fixes (12-15 times) per
day since it can only occur when the satellite is at a ship's zenith.
Global Multidimensional Systems - ANS The modern satellite navigation system used for
GNSS that provides latitude, longitude, and altitude from multiple satellites.
US Worldwide System - ANS GPS (Global Positioning System or Navstar).
Russian Worldwide System - ANS GLONASS (Global Navigation Satellite System).
EU Worldwide System - ANS Galileo.
User Equivalent Range Error (UERE) - ANS Natural errors which exist in the signal, including
atmospheric distortion, stability of the satellite clock, and errors in the transmission.
Geometric Dilution of Precision (GDOP) - ANS Total error relating to the spacing of the
satellites, including HDOP and VDOP.
Selective Availability (SA) - ANS An error in the signal intentionally placed by the military to
make the civilians' GPS receivers not as accurate as military ones.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
ANSWERS 100% PASS
Class A AIS - ANS Uses a reservation-based transmission system, which ensures transmission
will take place.
Class B AIS - ANS Searches for unused transmission time slots to make transmission and may
not transmit a signal if a large number of AIS systems are in the area.
AIS Range - ANS Line of sight around 20nm but may be higher (99nm) due to ducting.
Components of AIS - ANS 2 VHF Radio Frequencies.
Static Data in AIS - ANS Entered into the AIS installation and need only be changed if the ship
changes its name or undergoes a major conversion from one ship type to another.
Voyage Data in AIS - ANS Manually entered and updated during the voyage; usually does not
change over the course of the voyage.
Dynamic Data in AIS - ANS Information which could change rapidly or would want a quick
update if it changed; most are automatically updated from ship sensors.
Safety Messages - ANS Text alert sent via AIS.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Doppler Satellite Navigation Systems - ANS The first system for satellite navigation and
provides latitude and longitude from one satellite.
US System of Satellite Navigation - ANS SATNAV (Navy Navigation Satellite System), turned off
by the US government in 1996.
Russian System of Satellite Navigation - ANS Leo SATNAV, with Parus as the civilian system
and Tsikada-M as the military system.
Frequency of Obtaining Fixes - ANS This system can only take a few fixes (12-15 times) per
day since it can only occur when the satellite is at a ship's zenith.
Global Multidimensional Systems - ANS The modern satellite navigation system used for
GNSS that provides latitude, longitude, and altitude from multiple satellites.
US Worldwide System - ANS GPS (Global Positioning System or Navstar).
Russian Worldwide System - ANS GLONASS (Global Navigation Satellite System).
EU Worldwide System - ANS Galileo.
User Equivalent Range Error (UERE) - ANS Natural errors which exist in the signal, including
atmospheric distortion, stability of the satellite clock, and errors in the transmission.
Geometric Dilution of Precision (GDOP) - ANS Total error relating to the spacing of the
satellites, including HDOP and VDOP.
Selective Availability (SA) - ANS An error in the signal intentionally placed by the military to
make the civilians' GPS receivers not as accurate as military ones.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
