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| Concentric Indexing - a straight forward approach to controlled turns by Captain Paul Chapman |
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| Radar presentation | Use of stabilised electronic bearing line | ||
| Procedure for performing a planned turn | North up presentation | ||
| Planning considerations | Conclusion | ||
| Error sources and limitations | Resources | ||
| Adapting the technique to the radar available | |||
Adapting the technique to the radar available |
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All radars offer head up orientation but have different features.It can be seen from the preceding images that trails and being able to offset the VRM make monitoring the turn easy. (see figures 5, 6 & 7). Some models do not have trails available on head up mode, others curiously have stabilised trails on the head up mode. With radars that do not have the option to offset the VRM, the EBL can be offset with the range marker set at the reference point distance. This ranged EBL can be used to monitor the refence point path against the planned turn by rotating the EBL. (see figures 8 and 9) |
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Alternatively, it can be seen in Figure 9 that segments of the arc the reference point is to follow can be closely replaced by a line. In pilotage, where familiarity with the waters allows the pilot to know the path reference points should follow, head up with rings may be sufficient to monitor a turn and allows for the turn to have segments of different radii. |
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| Figure 9 - Offsetting the EBL to replace the arc the reference point is to follow | |||
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