Confusion About Active Sensors

[bringit133 (OP)]

I have a pretty good understanding of how active sensors work.  However there is one little thing that I am confused about.  I am creating a small fighter detection sensor for my sensor ship with the following stats.

Active Sensor Strength: 2400   Sensitivity Modifier: 180%
Sensor Size: 50 HS    Sensor HTK: 1
Resolution: 2    Maximum Range vs 100 ton object (or larger): 610,940,000 km
Range vs 1000 ton object: 61,094,000,000 km
Range vs 250 ton object: 3,818,375,000 km

The part I am confused about is the 100 ton or larger max range.  Since it says max range for 100 ton or larger does this mean that the stats for the 250 and 1000 ton ranges are incorrect since they are larger than 100t, and that their max range is really 600m? Or are the stats for 250 and 1000 correct and there is something I am forgetting?

[Ashery]

As far as I know, you are correct in that the max range for anything larger than a hundred tons is 610mil.

[DFDelta]

All the ranges shown there seem realistic to me.  You can see ships/fighters from further out if they are bigger.

100 ton = 610 million km
250 ton = 3. 818 million km
1000 ton = 61. 094 million km

Tough I have no idea if this distance is raising gradually (each ton counts) or in fixed steps (every 100 tons).

[sloanjh]

I have a pretty good understanding of how active sensors work.  However there is one little thing that I am confused about.  I am creating a small fighter detection sensor for my sensor ship with the following stats.

Active Sensor Strength: 2400   Sensitivity Modifier: 180%
Sensor Size: 50 HS    Sensor HTK: 1
Resolution: 2    Maximum Range vs 100 ton object (or larger): 610,940,000 km
Range vs 1000 ton object: 61,094,000,000 km
Range vs 250 ton object: 3,818,375,000 km

The part I am confused about is the 100 ton or larger max range.  Since it says max range for 100 ton or larger does this mean that the stats for the 250 and 1000 ton ranges are incorrect since they are larger than 100t, and that their max range is really 600m? Or are the stats for 250 and 1000 correct and there is something I am forgetting?

This is a bug.  I logged a detailed analysis in the bugs thread a few months ago - feel free to log a "me too" though because Steve probably forgot about it.  Basically, he forgot to look for the special case where the "smaller" (than resolution) sizes are actually bigger than the resolution shown.  The multiplier for targets smaller than resolution is min(1, (size/res)^2) - he left out the "min" function.  The top line is correct, the other lines should be the same range as the top line.  The same bug shows up for resolution 1 sensors - the smaller missile sizes are generally incorrect.

One more thing:  my opinion is that you should NEVER build a res-2 sensor.  You only give yourself a sqrt(2)x factor in additional range, but knock your anti-missile range down by (a crippling) 4x, which means you can't use the mounting ship as an AMM escort without adding another res-1 sensor.  It's cheaper (in mass) to build a single res-1 sensor that's 1.5x as big - that way you get yourself a dual-role escort.

John

[bringit133 (OP)]

Thanks sloanjh for clearing this up.  I wasn't really making that sensor for my ship, I was just using it as an example.  But I think that I will take your advice and throw this up on the bugs list.

[Steve Walmsley]

This is a bug.  I logged a detailed analysis in the bugs thread a few months ago - feel free to log a "me too" though because Steve probably forgot about it.  Basically, he forgot to look for the special case where the "smaller" (than resolution) sizes are actually bigger than the resolution shown.  The multiplier for targets smaller than resolution is min(1, (size/res)^2) - he left out the "min" function.  The top line is correct, the other lines should be the same range as the top line.  The same bug shows up for resolution 1 sensors - the smaller missile sizes are generally incorrect.

I have corrected the bug with regard to resolution 2+ sensors for v5.54 (and Newtonian). As far as I can tell, the missile sizes for the resolution 1 are correct. The size 6 missile is 30% of resolution 1, the size 8 is 40% and the size 12 is 60%. The 'minimum size' for sensor detection though is 0.33 HS, so the ranges should be 10.89%, 16% and 36% of the range of a 50 ton (1 HS) object

Steve

[sloanjh]

I have corrected the bug with regard to resolution 2+ sensors for v5.54 (and Newtonian). As far as I can tell, the missile sizes for the resolution 1 are correct. The size 6 missile is 30% of resolution 1, the size 8 is 40% and the size 12 is 60%. The 'minimum size' for sensor detection though is 0.33 HS, so the ranges should be 10.89%, 16% and 36% of the range of a 50 ton (1 HS) object

Thanks Steve.  On missiles, I suspect I didn't make myself clear.  The bug is that the range for a size 6 missile is not 10.89% of the resolution 1 range - IIRC they can be (significantly) larger.  If you're seeing 10.89% for size 6, then you've probably already fixed the missile bug previously....

John

[blue emu]

One more thing:  my opinion is that you should NEVER build a res-2 sensor.  You only give yourself a sqrt(2)x factor in additional range, but knock your anti-missile range down by (a crippling) 4x, which means you can't use the mounting ship as an AMM escort without adding another res-1 sensor.  It's cheaper (in mass) to build a single res-1 sensor that's 1.5x as big - that way you get yourself a dual-role escort.

John

In the 50 HS res-2 example given, Bringit133 would still be detecting res-1 targets at 15 m-km, and size-1 (to size-6) missiles at 1.5 m-km... so the specific example he gave will still serve fairly well as a DP AFTR/AM sensor. In general, though, you are correct in that a larger res-1 sensor is preferable to two seperate AM and AFTR sensors.