Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!ames!dftsrv!amarna.gsfc.nasa.gov!xrtnt From: xrtnt@amarna.gsfc.nasa.gov (Nigel Tzeng) Newsgroups: comp.sys.amiga.games Subject: Re: Harpoon...ASW Message-ID: <4045@dftsrv.gsfc.nasa.gov> Date: 29 Nov 90 19:38:22 GMT References: <1990Nov29.085633.20243@agate.berkeley.edu> Sender: news@dftsrv.gsfc.nasa.gov Reply-To: xrtnt@amarna.gsfc.nasa.gov Organization: NASA Goddard Space Flight Center - Greenbelt, MD, USA Lines: 92 News-Software: VAX/VMS VNEWS 1.3-4 In article <1990Nov29.085633.20243@agate.berkeley.edu>, felixh@headcrash.Berkeley.EDU (Felix Hack) writes... ^ ^ The Harpoon computer game's sonar model may be compared to the boardgame ^and to reality. Clearly we want it to be realistic, but the programmers ^are probably only interested in emulating the boardgame and hoping that ^system takes care of reality. Understandable. One assumes that Larry Bond knows what he is doing and for the most part I would tend to say he does ;-). Much more than I anyway. ;-) ^ While the computer game has the detection probabilities from the board- ^game built in, it's not possible to check whether all the sonar modifiers ^are done the same way (i.e. correctly). There's not even a uniform set ^of mods; take a look at the Harpoon ASW Forms Module for revisions to ^the sonar modifiers (higher speed to cavitate, for one thing). ^ Regarding changing depth to break track, changing depth shouldn't work ^against CZ detections. The scale of CZ is concentric circles of width of ^order 5 miles at ranges of order 30 miles and multiples thereof. The ^diagrams are grossly off true scale since they show depths of 1000 feet ^as large as something like 5 miles horizontally. I thought it might be so. The objective isn't to break the contact but to wreck the target solution. The standoff torps have limited detection and range once in the water so it might land far enough away not to find me. Twas not to be. I also noticed that the MK48 never seems to go into active mode (in regard to speed). At 40 knots it isn't going to catch anything in a stern chase. It does manage though but the display (when I select it as the active group) seems to read that it is cruising all the way to impact. I noticed once that on the recieving end I had some ship moving at flank speed away from a torp (say a couple miles away) which was hit maybe 30 sec later. I had figured the torp beaten since the difference in speed was very low and the range reasonable large. At best it shouldn't have hit until quite a few minutes later. ^ The RSR model seems reasonable. I have no access to data on real sonar ^performance vs hostile subs, but then who does? If you're trying to track ^enemy subs and you fail to detect them, you don't know it. Anyway, from ^all I've read and from playing lots of RSR I can't complain. ^ In the computer game the LA creeps at 5 knots, the improved LA at 10. ^While the former speed earns a quieting and sonar improvement bonus, the ^improved LA's speed does not earn a creep bonus in the boardgame. The ^improved LA is merely quieter and gets a -10% detection mod. The same ^seems to hold for the Trafalgar; it too creeps at 10 knots on the ^computer and gets -10% for its shrouded propulsor. Does the game (I didn't look at the data files in that detail) actually know about the mods between ships within the classes? I recall noticing that the ROF for the Tico was low enough not to look like the VLS launches. If I recall correctly (and that's an iffy proposition at best ;-) the Trafalgar has the 7 blade prop and not the propulsor. Would you infer that it wouldn't get the 10% bonus? ^ An LA at 0 knots still makes noise, since it has to operate machinery ^to keep the reactor cooled. This isn't much though. I've read that ^the boat is not any noisier cruising at a few knots than at full stop. ^I guess flow noise is low at first, and of course there's no cavitation ^at slow speeds. Hmmm..I understand that it will make noise. The question is whether this value is much above ambient. If it isn't you'll need some real awesome signal processing gear to filter out noise from signal at that level. There was a decent article in the Proceedings a few years back about the diminshing returns on passive sonar technology as noise levels go below ambient. Detection ranges in that case is not dependent on how sensitive your instrument but how good your computer is at filtering out background. Either way the range goes way down and they were concerned that in that event the solitary US sub will face multiple quiet Soviet subs at close range. It may tag the first guy only to be sunk by the companions. We certainly can't trade one for one. I've gone to 19 knots as in general they detect me at 5 knots anyway. It minimizes the time to when I can shoot back and I can still hear him. This is kind of silly but in the game it works a bit better than creeping...at least against subs with standoff weapons. About the only time I win those encounters is to pick him up and send a Nimrod after him but I consider that cheating on my part ;-). ^ I've heard rumors that the boardgame's ASW will be revised. I sure ^hope the computer game follows suit. This'll be good...I know quite a few avid board gamers but we've never been able to get into Harpoon. The computer version is fairly popular among the crowd though. ^ ^ Felix NT -------------------------------------------------------------------------------- // | Nigel Tzeng - STX Inc - NASA/GSFC COBE Project \X/ | xrtnt@amarna.gsfc.nasa.gov | Amiga | Standard Disclaimer Applies: The opinions expressed are my own.