[FIXED] (1307.9) Surface duct effect persists at deeper depth

[lumiere]

Sorry if I was mistaken/there was sonar model change, but it seems to me that sonar surface duct effect persists at deeper depth.

Previsously when spotter and target depth is both at <50m/165ft , there is surface duct effect and direct pass detection range is extended up to 15nm, while in other cases it reduces to 10nm: this is the green sphere shown directly around the sub.

Attached table is my sonar detection test result which I tested back in CMO v1.04. Left row shows spotter depth, top columm is target depth. Please note that at theorical max detection range is 15nm when both are at 131ft, others 10nm.

Then you test attached my "sensortesting" test scenario. Red sub (Victor III at 15kt) will come close to Blue sub, and when Red is detected range between two unit (=detection range) is shown. You can configure unit1 (Blue) and unit2 (Red) speed/depth by code shown at Blue Briefing.

I'm too lazy to make the same table, but got the following results:

Blue: 131ft
Red 131ft = 14.6nm
Red 167ft = 14.0nm
Red 250ft = 14.3nm

Blue: 167ft
Red 131ft = 14.6nm
Red 167ft = 14.5nm
Red 250ft = 14.6nm

Theorical max detection range are all 15nm, indicating that surface duct persists at deeper depth.
Thanks.

[Dimitris]

Thanks, good catch!

Tweaked this so that the benefit of surface ducting begins (very slightly) at 50m depth and increases in percentage as the sensor and/or the target nears the surface. The maximum benefit (1.5x of nominal direct-path range) happens only when both the sensor and the target are on the surface.

[lumiere]

Apologies for late reply but played Build 1307.11 and effect works fine. Thanks always for treaking.