From: mikkelhaaheim@gmail.com   
      
   Le lundi 26 septembre 2016 01:19:13 UTC+2, Rick Pikul/Chakat Firepaw a   
   écrit :   
      
   > >> Wrong, you don't need to look at everything at all times.  This is one   
   > >> of the two constant errors pro-stealth people make.   
   > >>    
   > >> Instead you look at any given direction periodically, using a search   
   > >> pattern that makes it impossible to manage to 'sneak though' by moving   
   > >> from areas about to be scanned to ones that were just scanned.   
   > >    
   > > Remember, stealth is not about not being seen, but about not being   
   > > noticed. Looking all the time means that you have more opportunity of   
   > > spotting intermittent burns that might indicate something worth paying   
   > > attention to.   
   >    
   > OK, I take it you don't know how long the burns are for interplanetary    
   > travel.  Even using high-thrust drives, (which can be seen from Pluto),    
   > you are talking several minutes at a minimum for departure burns.   
   >    
   > Given sensor platforms which do a scan every 12 minutes, assuming just    
   > four platforms means you get looked at every three minutes.  So you will    
   > be spotted at least once or twice during your burn.   
   >    
   > Using the 'hummingbird power' of things like electric drives does mean    
   > you are harder to spot, but now your correction burns are an hour long.   
      
   I thought I had mentioned this, but you are ignoring the fact that continuous   
   thrust is not necessary. 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.   
      
   For that matter, your 12 minute scan time is FAR from realistic, assuming you   
   actually want to detect anything.   
      
   >    
   >  When you scan, the holes are not places where a ship is   
   > > not detected so much as they are occasions where the activities (burns)   
   > > of that ship do not send up flags.   
   > > Seaarch patterns are okay, but you are not going to see what is actually   
   > > happen. You are not going to see the energy spikes produced by a burn,   
   > > or the launch of an assault force of drones from an NEA or common cargo   
   > > transport.   
   > > Scans also make it much more likely that two intermittent spikes will be   
   > > interpreted as anomalies, rather then manoeuvres from a single object.   
   >    
   > A transient detected by the primary scan means that the secondaries are    
   > looking at you.  You don't dismiss anything as an anomaly at the simple    
   > detection level.   
      
   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.   
      
   >    
   > >> > A single degree field of view is MUCH more likely (still probably   
   > >> > somewhat generous),   
   > >>    
   > >> Getting a 0.8 degree field of view with a single sensor that could do   
   > >> 1.5 FOV/s was possible _TWENTY YEARS AGO_.  That gives you two whole   
   > >> sky surveys, (not a band, the full 4pi steradians), per day using   
   > >> hardware that isn't as good as the phone in your pocket.   
   > >    
   > > 1.5 FOV/s is possible with small sensors. It is not possible with the   
   > > 35m dishes required for detecting weak signals.   
   >    
   > That figure was for a 2m scope that could detect a 2.5e-17W/m^2 signal,    
   > using 1993 technology.   
      
   Perhaps. IFF the source were large enough to begin with, or if it were   
   refering to the flux density arriving at the platform.   
   Site your sources... at least by indicating which platform you are refering   
   to. I think you will find that the information does not say what you think it   
   says.   
      
   >    
   > > But that doesn't matter,   
   > > because you are forgetting that you will be dealing with a developed   
   > > community of spacefarers. Local traffic between moons is going to be on   
   > > the level of city street traffic. Traffic between adjacent planets will   
   > > be on the level of interstate traffic. Even traffic between Jupiter and   
   > > Earth will be on the level of international traffic between Europe and   
   > > the US (several flights per day... or, if you prefer, several departures   
   > > per day of ocean vessels).   
   >    
   > Do you know what an active space port means?   
   >    
   > It's a place that gets a couple dedicated sensors watching it, and just    
   > it.  All of that regular traffic is going to be tracked, (you can also    
   > expect a very strict set of rules about filing flight plans, given that    
   > every ship is a WMD).   
      
   Nonsense.    
   Perhaps in the near future era when there are only two or three active   
   spaceports. Certainly NOT in the era when spaceports are as common as modern   
   airports.   
   A Cessna with a few dozen grams of Cobalt is a potential WMD. We have enough   
   trouble tracking the cobalt, let alone all the Cessnas. We have managed so   
   far, mostly out of luck, and the fact that the people who would actually want   
   to try such a thing    
   generally don't have much access to radiologic material. Yet.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)