From: mikkelhaaheim@gmail.com   
      
   Le jeudi 27 octobre 2016 04:06:46 UTC+2, Rick Pikul/Chakat Firepaw a écrit :   
      
   > For departure burns, they really do need to be continuous.  You only have    
   > those few minutes to do the burn.  If you spread it out you miss your    
   > window.   
      
   They REALLY don't. The burn rate gets factored in to the launch window. You   
   only really have a concern if you are rather low in a gravity well, and the   
   pulse rate is not sufficient to overcome "gravity drag".   
      
   >    
   > Correction burns using high-thrust drives could dodge between scans, but    
   > at the price of either needing to have a nice hot reactor that has to    
   > stay on for the whole time or a chemical rocket and a very limited delatV    
   > budget.  Low thrust drives and you still have hours of thrusting no    
   > matter how you break it up.   
      
   Again, it is not a matter of "dodging" between scans. It is a matter of   
   limiting detectable emissions during scans.   
   Low thrust drives will probably be running days, weeks, or months... overall.   
      
   >    
   > > Even assuming a 6° FOV, you will   
   > > only be looking in the direction of a target for 12 seconds out of that   
   > > 12 minutes, or 48 seconds for your 4 platforms. If the target makes 5 1   
   > > minute burns / hour, you will have well below 10% chance of detecting   
   > > the burn, even assuming the burn was at ful thrust in the direction of   
   > > one of the platforms.   
   >    
   > I think you should check your math:  Making five 1 minute burns in a hour    
   > has an 8.3% chance of being spotted by a single instantaneous look during    
   > that hour.   
      
   And EVERY scan cycle will have that same 8.3% chance of detection. That 8.3%   
   chance is 17% below my 10% chance estimate (to be clear, that is 17% of 10%),   
   which, in my opinion, is well below that 10%.   
   As it turns out, though, your figures were based on faulty information. The   
   base figure you used was off by a factor of 12.   
      
      
   >    
   > > For that matter, your 12 minute scan time is FAR from realistic,   
   > > assuming you actually want to detect anything.   
   >    
   > And we're back to your ludicrously low emissions figures.   
      
   In your opinion.    
   But, no. Your 12 minute scan time was based on faulty information. At best, it   
   would actually work out to be 144 minutes. That figure does not take into   
   account the further error regarding the required exposure time.   
      
      
   > > If you don't dismiss anything as an anomaly, you re going to be spending   
   > > all your time chasing ghosts. You are helping your target, because you   
   > > no longer have the resources left to analyse their actions.   
   >    
   > There will be at least one secondary for every primary, unless you think    
   > that there are going to be false positives every couple of 'frames' then    
   > there is no swamping of the systems.   
      
   Depends how you are defining "false positives". But, yes, if I recall   
   correctly (I will double check the information), given the number of pixels   
   involved, there ARE inherent false positive signals occuring at least every   
   couple seconds. Of course, this    
   does not take into account all the little bits of dust and debris in space...   
   many of which tend to come off of your own platform.   
      
      
   > Already done, it's from a discussion on this very newsgroup almost 20    
   > years ago by someone who actually works, (or at least worked, I don't    
   > know if he has retired since then), with this kind of stuff.   
      
   I don't have the time to go through all the old posts. NAME THE PLATFORM.   
      
      
   > I'm not talking space port as in "deGrasse Tyson Station" I'm talking    
   > about space port as in "Saturn".   
      
   Then even more ships are going to slip by undetected.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)