Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!clyde.concordia.ca!nstn.ns.ca!news.cs.indiana.edu!know!samsung!rex!wuarchive!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!cbnews!cbnews!military From: edremy@elaine33.stanford.edu (eric remy) Newsgroups: sci.military Subject: Re: How to See in the Dark: Three ways Message-ID: <1991Feb6.031604.20823@cbnews.att.com> Date: 6 Feb 91 03:16:04 GMT References: <1991Feb5.041807.5114@cbnews.att.com> Sender: military@cbnews.att.com (William B. Thacker) Organization: Stanford University - AIR Lines: 46 Approved: military@att.att.com From: edremy@elaine33.stanford.edu (eric remy) In article <1991Feb5.041807.5114@cbnews.att.com> ee5391aa%triton.unm.edu@ariel.unm.edu (Duke McMullan n5gax) writes: > >Last: passive infrared imagers. I've never seen one of these or read detail- >ed info, so perhaps someone else can fill in the gaping holes. Passive thermal sights are one of the best things to come down the road in a long time. All modern US tanks are equipped with one; (M1, M1A1, and M60A3 with TTS (Tank Thermal Sight.)) my experience is with the 60A3 TTS. Effectiveness: Very. Since they work from the heat given off by objects, anything warm blooded or powered machinery are picked up no matter what time of the day. Other objects (rocks, trees) are warmed by the sun, and so late in the day and just before dawn are indeed the two worst times, however, you can still see reasonably well. Under ideal conditions, I've picked up rabbits and foxes at distances of >1 kilometer. Thermal sights have the additional advantage that they see through most forms of camoflage and smoke. The image can be degraded by rain, snow, or certain types of smoke such as white phosphorous. Picking up people is no problem: close enough and you can tell what they're wearing, skin color, etc. Air vents and such wouldn't be a problem if they were giving off heat of some kind. I'm not certain exactly how they're cooled. The TTS in a 60 has a small refrigerator which makes a horrible racket, but I don't really know what the cooling fluid is. They do have to be chilled to cryogenic temps to work well. Cost: I'm not really sure here. My instructor on the TOW missile told me that the thermal sight for a TOW runs about $50,000. I've never been given a price on the TTS: be assured that it's in the tens of thousands. It's also worth every penny. It makes night fighting a realistic possibility, increases chances of finding a target at any time of the day, and is generally the neatest toy on the tank... Hope this helps. -- ------------------------------------------------------------------------- Eric R. edremy@d31ha2.Stanford.EDU Deparment of Chemistry "Any desired property can be calculated from the Schrodinger equation of the system. The solution is left as an exercise for the reader." JIR, 3rd ed.