Basic on E-Nav 2
basic on electronic navigation 2
APPENDIX
Definitions of terms to be used in connection with ARPA performance standards
1. Target means any object fixed or moving whose position and motion is determined by measurements of range and bearing on radar.
2. Relative Course means the direction of motion of a target relative to own ship’s position expressed as an angular displacement from north. It is deduced from a number of measurements of target range and bearing or own ship’s radar.
3. Relative Speed means the speed of a target relative to own ship’s position. It is deduced from a number of measurements of target range and bearing on own ship’s radar.
4. Relative Motion means the combination of relative course and relative speed.
* Refer to IEC 872: Marine Automatic Radar Plotting AIDS (ARPAs)
5. True Course means the true direction of motion of a target expressed as an angular displacement from north. It is obtained by a vector combination of target relative motion and own ship’s true motion.
6. True Speed means the speed of a target obtained by a vector combination of target relative motion and own ship’s true motion
7. True Motion means the combination of true course and true speed.
8. True Bearing means the direction of a target from own ship expressed as an angular displacement from north.
9. Relative Bearing means the direction of a target from own ship expressed as an angular displacement from own ship’s heading.
10. True Motion Display means a display across which own ship and each target moves with its own true motion.
11. Relative Motion Display means a display on which the position of own ship remains fixed and all targets move relative to own ship.
12. Azimuth Stabilised Display means a display in which the azimuth orientation relative to a nominated true bearing is fixed.
13. North-Up Display means an azimuth-stabilised display in which a line connecting the centre with the top of the display is north true
APPENDIX
Definitions of terms to be used in connection with ARPA performance standards
1. Target means any object fixed or moving whose position and motion is determined by measurements of range and bearing on radar.
2. Relative Course means the direction of motion of a target relative to own ship’s position expressed as an angular displacement from north. It is deduced from a number of measurements of target range and bearing or own ship’s radar.
3. Relative Speed means the speed of a target relative to own ship’s position. It is deduced from a number of measurements of target range and bearing on own ship’s radar.
4. Relative Motion means the combination of relative course and relative speed.
* Refer to IEC 872: Marine Automatic Radar Plotting AIDS (ARPAs)
5. True Course means the true direction of motion of a target expressed as an angular displacement from north. It is obtained by a vector combination of target relative motion and own ship’s true motion.
6. True Speed means the speed of a target obtained by a vector combination of target relative motion and own ship’s true motion
7. True Motion means the combination of true course and true speed.
8. True Bearing means the direction of a target from own ship expressed as an angular displacement from north.
9. Relative Bearing means the direction of a target from own ship expressed as an angular displacement from own ship’s heading.
10. True Motion Display means a display across which own ship and each target moves with its own true motion.
11. Relative Motion Display means a display on which the position of own ship remains fixed and all targets move relative to own ship.
12. Azimuth Stabilised Display means a display in which the azimuth orientation relative to a nominated true bearing is fixed.
13. North-Up Display means an azimuth-stabilised display in which a line connecting the centre with the top of the display is north true