Local Magnetic Anomaly - Portrayal of Curves & Surfaces

[alvarosanuy]

S-52 LUT use Grey and not magenta colour to depict LOCMAG linework Area features.

I propose the following changes for the portrayal of LocalMagneticAnomaly features in S-101 :

• [ ] Curve - Do we really need Curves for this type of feature??

• [ ] Areas Plain Boundaries - Propose replacing SY(LOCMAG51);LS(DASH,1,CHGRD) with SY(LOCMAG51);LS(DASH,1,CHMGD). LOCMAG51 will sit in the middle of the area.

• [ ] Areas Symbolized Boundaries - Propose replacing SY(LOCMAG51);LC(NAVARE51) with SY(LOCMAG51);LC(CTYARE51). LOCMAG51 will sit in the middle of the area.

• [ ] Also, I propose we incorporate the magnetic anomaly value label to all 3 geometry types (Point, Curve & Surface). Refer to https://github.com/S-101-Portrayal-subWG/Working-Documents/issues/102

• [ ] Propose magnetic label colour is amended to CHMGD. Testing has demonstrated they are hard to read when CHMGF

[alvarosanuy]

Decisions made at Portrayal subWG meeting on 18/10/23

• [x] NIWC - Amend colour of Curve and Surface linework to CHMGD
• [x] NIWC - Update colour of magnetic legend (all geometries) to CHMGD
• [x] NIWC - Produce screenshots with deep and shallow background in Day, Dusk and Night modes.
• [x] NIWC - Repeat the action above but using Black colour for legends.
• [ ] PsWG - confirm magnetic legend colour preference for PC 1.2.0 once screenshots are uploaded to this issue.

[DavidGrant-NIWC]

The centered area symbol looks a little odd now since it's a different color (CHMGF) then everything else (CHMGD).

Also, the appearance is no longer consistent with MagneticVariation features, which use black labels and a mix of CHMGF and CHMGD (and no area outline):

Plain Boundaries	Underlying Depth	Labels	Day	Dusk	Night
Off	Shallow	Black
On	Shallow	Black
Off	Deep	Black
On	Deep	Black
Off	Shallow	CHMGD
On	Shallow	CHMGD
Off	Deep	CHMGD
On	Deep	CHMGD

[alvarosanuy]

Also, the appearance is no longer consistent with MagneticVariation features, which use black labels and a mix of CHMGF and CHMGD (and no area outline):

I believe the best way forward is to keep it simple. Therefore I propse:

Retain LocalMagneticAnomaly portrayal as per S-52 wit the following 3 exceptions only:

• [ ] Add magnetic legend (text) to all geometries using Black colour (as per MagneticVariation features).
• [ ] Areas Plain Boundaries - Replace SY(LOCMAG51);LS(DASH,1,CHGRD) with SY(LOCMAG51);LS(DASH,1,CHMGD). LOCMAG51 will sit in the middle of the area.
• [ ] Areas Symbolized Boundaries - Replace SY(LOCMAG51);LC(NAVARE51) with SY(LOCMAG51);LC(CTYARE51). LOCMAG51 will sit in the middle of the area.

Point Geometry - Simplified and Paper Chart Point options stay as per S-52. Curve Geometry - As per S-52

[DavidGrant-NIWC]

| [...] LOCMAG51 will sit in the middle of the area.

LOCMAG51 has a large offset. Do you mean that the pivot point will sit in the middle of the area?

• [x] Add magnetic legend (text) to all geometries using Black colour (as per MagneticVariation features).
• [x] Areas Plain Boundaries - Replace SY(LOCMAG51);LS(DASH,1,CHGRD) with SY(LOCMAG51);LS(DASH,1,CHMGD).
• [x] Areas Symbolized Boundaries - Replace SY(LOCMAG51);LC(NAVARE51) with SY(LOCMAG51);LC(CTYARE51).

Plain Boundaries	Underlying Depth	Day	Dusk	Night
Off	Shallow
On	Shallow
Off	Deep
On	Deep

[alvarosanuy]

LOCMAG51 has a large offset. Do you mean that the pivot point will sit in the middle of the area?

Leave as is for now.

Unless I hear something different I would proceed and CLOSE this issue on Monday 27/11/23.

[DavidGrant-NIWC]

PC issue 283 has been closed based on @alvarosanuy comment of 20NOV23. Recommend this issue is closed as well.