[KaleunMarco]

Originally Posted by Sniper297

Don't have 1.5, so don't have OpMonsun, so no Brit destroyers or Underzee Boots. I recall reading somewhere that on some of these supermods they disabled the visual range ring, I would guess that's what you have there - no visual range ring, outer is radar, second largest with the wedge cut out astern is the standard passive (hydrophone, something ending with a P), the semi circle is the standard active. The one shaped like a 1/3rd slice of pie is possibly another type of active sonar, no idea how they pulled that trick off.

The "NULL" means it's not used at all, ever. What the D and C stand for I have no clue, so take a look at the SNS file for this A&B class and see if one of those is active. Toward the end of WWII the US was experimenting with a new type of sonar called FM, which was a separate system for detecting mines. I've also read a few references to the Japanese playing with MAD (Magnetic Anomaly Detector) but only in aircraft. So wild guess it's a different kind of active sonar, don't know what else it could be with that shape. Again, keep in mind the visible rings only show the average, the max range of whatever system you see the rings for is actually a little bigger depending on the AI crew - which there's no way of knowing.

i should have posted the .SNS values with the graphic. what can i say....
listed below are the Sensor definitions for the DD-A&B for the time period of the graphic, which is Jan-Feb 1943. i removed the other definitions in an effort to keep some control over the length of this post. as you can see, there are four related definitions, so it possible that visual is included even though it is mostly-dark at the time of contact.
[Sensor 1]
NodeName=O01
LinkName=Escort_Visual
StartDate=19380101
EndDate=19451231

[Sensor 3]
NodeName=H01
LinkName=Type128P
StartDate=19420601
EndDate=19430601

[Sensor 6]
NodeName=N01
LinkName=Type128A
StartDate=19410601
EndDate=19440101

[Sensor 9]
NodeName=R01
LinkName=Type286
StartDate=19410301
EndDate=19430301


i wonder where are the Visual and Radar definitions stored?