Hydrophone Use

[CapnScurvy]

Last week, a gamer asked in my Optical Targeting Correction thread:

I installed this mod and it seems to have broken the hydrophones in my Gato. Essentially, my hydrophone operator hears things that nobody else can; he calls out hydrophone contacts but when I go to listen for myself, all I can hear is the soothing sound of empty sea.

I gave him an answer referring to the stock game as the problem. Either the sound files are missing or some other issue that doesn't relate to OTC. While this is true in some cases, I've done some in-depth tests to see just what's happening with the passive hydrophones and your ability to hear some target engine sounds and not others. It's not related to OTC, nor is the issue initially related to any mod. Although, any mod adding single or patrol missions (campaign missions) to the game could be causing the problem. I've spent well over 20 hours testing the hydrophone, its capabilities, its short comings, and have found the following.

The targets actual speed compared to its maximum rated speed is what allows the target "hyd" sound file to be heard. Simply put, if the target's speed is less than half the rated maximum speed for the ship......you won't hear a thing through the passive hydrophone. Turning the sonar dial all you want, you'll not hear the target. Even though your Sonarman called out the detection and displayed the results on the message text board. Having the target traveling at least half the maximum speed (or greater) allows for the target to be heard through the passive hydrophone use.

Unfortunately there isn't anything that can be done to change this within the parameters of the Sensors.sim file.



Above is the RFB 2.0 Sensor.sim file found in the "Data/Library/USSubParts/" folders. There are 4 entries for the different hydrophones types RFB uses. The hydrophone that's highlighted is the "ball" type found on the S Class type boats. The others are similar, except for the MaxSensorHeight parameter and the MaxRange. The RPMDetLevel my cursur is pointing to, I thought, has something to do with detection. The short version.....this parameter doesn't change a blessed thing! I had it with negative numbers; positive numbers from fractions to 100.....and nothing changes. If a target ship is traveling below 50% of its maximum rated speed found in the target ships .sim file.....you'll not hear it through the hydrophones.



Believe me, I tried several different things. Nothing changed the outcome. Except for raising the cruising speed of the target ship, or decreasing the specific ships max_speed parameter in the above file.....your hydrophone pickup of sounds will be nonexistent.

Just thought you folks that write missions should know.