Vertical Beam Divergence: Difference between revisions

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m (Dictionary clean-up: identifier → urn:mrn:iala:dic:14-1-0014; section 2.1 → 14.1 Aids to Navigation Visual Signalling (Chapter 14 Marine AtoN Design and Delivery))
 
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'''urn:mrn:iala:dic:14-1-0014'''
The angle of the light beam between points where the intensity has fallen to a fraction of the maximum intensity within the beam.
The angle of the light beam between points where the intensity has fallen to a fraction of the maximum intensity within the beam.


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[[Image:Vertical_Beam_Divergence_plot.jpg|none|frame|right|400px|figure 1]]
[[Image:VerticalBeamDivergencePlot.jpg|none|frame|right|400px|figure 1]]
 
 
Note: In the past, lantern vertical divergence was defined as the angular separation of the upper and lower 10% intensity points in the intensity profile Full Width Tenth Maximum (FWTM).  More recently, lantern divergence has been defined by the Full Width Half Maximum (FWHM) intensity, the angular separation of the upper and lower 50% intensity points in the intensity profile.
 
 
 


Source: ENG7, Guideline G1065
Source: ENG7, Guideline G1065


{{languages|Codes on Alerts and Indicators}}
{{languages|Vertical Beam Divergence}}
[[Category:2.1 Optics and Vision]]
[[Category:14.1 Aids to Navigation Visual Signalling]]
[[Category:Alphabetical Index]]
[[Category:Alphabetical Index]]
[[Category:IALA Dictionary 2017 Revision]]
[[Category:IALA Dictionary 2018 Revision]]
[[Category:Approved by Council through approval of source document]]
[[Category:Approved by Council through approval of source document]]
[[Category:IALA Dictionary 2023 Revision]]

Latest revision as of 10:15, 17 September 2026

urn:mrn:iala:dic:14-1-0014

The angle of the light beam between points where the intensity has fallen to a fraction of the maximum intensity within the beam.

The vertical divergence is typically specified between the first points where the intensity falls to 50% of the maximum.


figure 1


Note: In the past, lantern vertical divergence was defined as the angular separation of the upper and lower 10% intensity points in the intensity profile Full Width Tenth Maximum (FWTM). More recently, lantern divergence has been defined by the Full Width Half Maximum (FWHM) intensity, the angular separation of the upper and lower 50% intensity points in the intensity profile.



Source: ENG7, Guideline G1065