Thursday, September 22, 2016

I Can See Clearly Now That The Hyperspectral Goggles Are On! I Can See All Obstacles In My Waaayyyy!

I seeeee yoooouuuuu.
Human sight is an amazing thing and is among the keenest in the animal kingdom. It can see in a wide range of colors and with amazing detail. However, it is not without limitation. We do not see well in the dark, we cannot see the heat emanating from the objects around us and we only see a very limited spectrum of the light available to us.

Thankfully modern technology has given us all sorts of passive visual sensors as the tools needed to overcome these limitations and the up coming ultra-technology around the corner is set to blow them out of the water!

GURPS Ultra-Tech gives a surprisingly good range of options for passive visual sensors, at lest at the human scale, and even gives options for higher tech level version of them. But as is normal for the book, if you want something specific or a wider range of options... well you're kinda out of luck. Once again I can not stress how much of a bad idea it was to cut the custom gear angle that this book was originally supposed to have. But I degrees.... 

It also doesn't line up with some of the options in GURPS High-Tech which are points brought up in Tactical Shooting: Tomorrow by Hans-Chirstian Vortisch in Pyramid 3/55 Military Sci-Fi.

So being the crunchmeistier I am, I decided to fix this little problem.

The below rules lets you create any of the types of passive visual sensors listed in Ultra-Tech and updates how they are designed to bring them more in line with Ultra-Tech. As always, keep in mind that my numbers could be off and even if they aren't Ultra-Tech's numbers can be iffy at times. Also updating some things to how things are handled in High-Tech could also thrown of some factors so not everything designed with these rules will line up 100% with what's in the book.

Passive Visual Sensor Design System (Yeaaaay for creative names!)

Tech Level
First pick the Passive Visual Sensors Tech Level, either 9, 10, 11 or 12. The higher its Tech Level, the lighter it can be made for a given level of magnification.

Example: Let's make a next generation TL9 rifle scope.

Passive Visual Sensor Type
Next pick the type of Passive Visual Sensor you are going to use. See GURPS Ultra-Tech pg. 60-61 for the full rules for each type of Passive Visual Sensor. It should be noted that all TL9+ Passive Visual Sensors are variable-power optics that can zoom between 0 and their max magnification.

Night Vision Optics (TL9)
These use light amplification technology to increase the apparent levels of ambient light. They can also be use as a normal day light visual optic as well. Even in this mode they still gives the Night Vision Advantage at level 1 .

All other type of Passive Visual Sensors can set to be used as a Night Vision Optic if needed. Doing so doubles the duration of the power cell powering the sensor if using a Infrared Imaging Sensor, quadruples it if using a Hyperspectral Imaging Sensor and by a factor of eight if using a Passive Electromagnetic Sensor Array.

Night Vision Optics give a given level of the Night Vision Advantage based on their Actual Vision Bonus. Night Vision 7 if +0, Night Vision 8 if +1 and Night Vision 9 if +2 or higher.

Infrared Imaging Sensor (TL9)
These build up a false color imagine of the surroundings based on the levels of infrared radiation it picks up. This sensor will work even in total darkness.

Hyperspectral Imaging Sensor (TL9)
This is also known as a sensor fusion or a multi-spectral sensor unit in the real world and represents the next generation of real Passive Visual Sensors and is set to be a game changer. They work by building up a false color image though the blending of imputes of an array of different visual sensors which in turn often reveals more detail then if just using them independently. Their downside is that that they are heavier for a given level of magnification then Infrared and night vision optics, use more power and are very expensive.

Passive Electromagnetic Sensor Array (TL10)
A more advanced version of the Hyperspectral Imaging Sensor that increases the frequencies of electromagnetic radiation it can see across. This of course makes it even heavier and power hungry.

Example: Looking through the choices, a Infrared Imaging Sensor seems like the best choice for making a rifle scope at TL9.

Base Passive Visual Sensors Aim Bonus
Now pick the Base Aim Bonus you want for the sensor. Its Base Aim Bonus is simply the best bonus a given platform can give for its weight.

One thing to keep in mind is that realistically, while the sensors will get lighter as technology improves, the actual size of their lens will not (at lest not by that much) since there is a limit to how small you can make a lens and still have enough area to collect the necessary amount of light.

Example: Since this we want to mount this to a relatively normal sized rifle platform we don't want our optic to be too big so a bonus of +5 seems about right.

Base Magnification Level
Now that we know the base bonus we want, we can then figure the maximum base magnification we can get.

Base Magnification Level = 2^Ab

Ab is the Base Passive Visual Sensors aim bonus.

Example: Since we want a Base Aim Bonus of +5, this means our optic is going to have a Base Magnification Level of 2^5 or 32×. 

Or if you want you can choose your Base  Passive Visual sensors Magnification level first and figure its Base Aim Bonus from that.

In that case, Aim Bonus = Log2(Ml)

Ml is the passive visual sensors magnification level.

Example: If we decided to choose the Base Magnification Level of 32× first we could figure our Base Aim Bonus taking the Log2 of its Magnification which is +5.

Visual Range
Next we figure how much we want the sensor to restrict our range of vision. This will also effect the sensors cost.

Tunnel Vision
This is typical of most telescopic scopes. A Passive Visual Sensor with this Visual Range option gives the Tunnel Vision Disadvantage when being used.

120° Restrictive Vision. 
This is typical of many modern optic goggles, it gives you more visual range then a typical scope but you still have blind spots. This gives the No Peripheral Vision Disadvantage when in use.

Full Binocular Vision
This option does not restrict a users vision at all.

Example: Since we are building a rifle targeting scope giving it the Tunnel Vision option makes the most sense.

Passive Visual Sensors Weight
Now that we know its Tech Level, the type of Passive Visual Sensor it is, its Base Magnification Level and its Visual Range we can figure the sensors weight.

Weight = (((Mlb/48)^2)×Su×Uc)/TL

Mlb is the passive visual sensors base Magnification Level.

Su is the type of passive visual sensor you are using. It is 1 for a Standard Visual Sensor, 2 for a Infrared Visual Sensor, 4 for a Hyperspectral Sensor and 8 for a PESA.

Uc is 1 for a passive visual sensors that grants Tunnel Vision, 2 if it has 120° Restricted Vision and 3 it has Full Binocular Vision.

TL is 1 if TL9, 2 if TL10, 4 if TL11 and 8 TL12.

Example: Since this a TL9 32× power Infrared Visual Sensor scope that gives Tunnel Vision it weighs ((32/48)^2×2×1)/1 or 0.97lbs which we round up to 1lbs.

A TL9 A cell will power the Passive Visual Sensor for (1/Sw)*TL hours. Note that the figures in Ultra-Tech seemed to be rounded off to the nearest power of 10. For example a B cell should only power a given sensors goggle or visor form factor for 6hrs but it is round up to 10hrs.

Sw is the Passive Visual Sensors weight.
TL is 1 at TL9, 4 at TL10, 16 at TL11 and 64 at TL12.

 For longer durations use bigger or more power cells.

Example: Since our infrared scope is TL9 and weights 0.5lbs a single C cell will power if for (1/1)*1 or 1hrs. This is a bit low so bumping up the power cell to a B cell will increase duration to 10hrs. This will add 0.05lbs to the scopes weight. 

Lens Quality
Now that figured out how much your Passive Visual Sensor weighs its time to figure how high its quality is. This will effect the sensors cost, the lower the level of magnification is for its size the cheaper it will cost to buy.

Best Quality
This lets you use the scopes full magnification and bonus but makes the scope expensive.

Excellent Quality
This halves the scopes Base Magnification and drops the Base Aim Bonus by 1.

Good Quality
This quarters the scopes Base Magnification and drops the Base Aim Bonus by 2.

Fair Quality
This drops the scopes Base Magnification by a factor of 8 and drops the Base Aim Bonus by 3.

Poor Quality
This drops the scopes Base Magnification by a factor of 16 and drops the Base Aim Bonus by 4. 

If the quality level you pick drops your Base Aim Bonus below 0, you can not take this quality level, pick the next higher quality level up. 

So this makes your Passive Visual Sensors actual Magnification Level = Mlb/Lq

Mlb is the Passive Visual sensors Base Magnification Level.

Lq is 1 if best Quality Lens, 2 if Excellent Quality, 4 if Good Quality, 8 if Fair Quality and 16 if Poor Quality.

Example: Our scope with have an actual Magnification of  32× if Best quality, 16× if Excellent Quality, 8× if Good Quality, 4× if Fair if Fair Quality or 2× if Poor Quality.

And its actual Aim Bonus = Ab-Lq

Ab is the Passive Visual Sensors Base Aim bonus.
Lq is 0 if best Quality Lens, 1 if Excellent Quality, 2 if Good Quality, 3 if Fair Quality and 4 if Poor Quality.

Example: Our scope with have an actual Aim Bonus of  +5 if Best quality, +4 if Excellent Quality, +3  if Good Quality, +2 if Fair if Fair Quality or +1 if Poor Quality.


Cost = $250×Sw×Lq×Su.

Sw is the Passive Visual Sensors weight.

Lq is 1 if Best Quality lens, 0.8 if Excellent Quality, 0.6 if Good Quality, 0.4 if Fair Quality and 0.2 if Poor Quality.

Su is 1 if Night Vision Optics or Infrared Imaging Sensor or 8 if Hyperspectral Imaging Sensor or Passive Electromagnetic Sensor Array.

Example: Since our scope is a Infrared Imaging Sensor and weighs 1lbs it cost $250×1×1×1 or $250 if Best Quality, $200 if Excellent Quality, $150 if Good Quality, $100 if Fair Quality or $50 if poor Quality.

Optional Rule: Lens Diameter
If you want a little extra detail then the diameter of a lens should be at lest 7mm ×the Passive Visual Sensors Base Magnification (not it's actual one). It is possible to make smaller lens but you start to run into resolution problems and issues with night vision. This does not go down with with TL! While we are not able to make perfect lenses yet and there *IS* some room for improvement... it's not by much and we're talking fractional differences at most.

Example: Since our scopes Base Magnification is 32× this means its lens needs to have a diameter of at lest 32×7 or 224mms.

Optional Rule: Form Factor
Ultra-Tech pg. 60 has some good guidelines for what extra gear you should add and Visual Range options you should choose based on the type sensor you want. Below I will give some extra notes on some of the options that might need further clarification with these rules as well as add a new option.

Goggles, Visor, Video Glasses or Video Contacts
These should be built with the Binocular Visual Range option.

Targeting Scopes
These are used for giving the best magnification possible for long distance shooting. They used the Tunnel Vision Visual Range option.

Optional Rules: Sensor Turrets and Periscopes
Some things seems a bit off with the weight of Sensor turret and Sensor Periscope.  The hold a 10× Hyperspectral Imaging Sensor and a 10 mile range Ladar which should weigh less then 3lbs combined and cost less then $20,000 yet the turret weights 70lbs and costs $300,000 and the periscope weighs 150lbs and costs $350,000!

Needless to say, these figures seem more then a little off to me. Keep in mind that these figures don't take into account the possibility that the Combination Gadget rules weren't used which would make these figures even more wonky. So as a fix I propose that turrets weigh and cost 1.2 × more then the combined weight and cost of the sensors used in the turret and that periscopes weighs and cost (1+(0.1×how many yards tall the periscope is)) times more.If you want it to be both a turret and a periscope multiply the weight and cost by both.

Example: If we wanted to make my 1lbs scope a sensor turret it would now weight 1.2lbs and cost (assuming a Best Quality lens) $300. If it was a 5 yard periscope it would now weigh 1.5lbs and cost $375. If it was both a turret and a 5 yard periscope it would weigh 1.9lbs and cost $450. 

Warping it up
All you have left to do is think up any equipment modifiers and or perks/quirks you might want to add, write up the stat line and think up any flavored fluff text you might want to add.

Example: To add some flavor to this scope let's say it's a military grade scope made to last and there for counts as rugged and made by a company called Hugues Optics. 

Hugues Optics Oracle XL-5 224mm Infrared Imaging Scope (TL9)
The Hugues Optics Oracle XL-5 224mm series of infrared imaging scopes are built to military specs and designed to last (counts as rugged). They are available in  32× (+5) power for $500, 16× (+4) power for $400, 8× (+3) power for $300, 4× (+2) for $200 and 2× (+1) for $100.

The unit weights 1.25lbs and is powered by  a B cell for 10hrs. DR 8 HP 4 HT 12.


  1. Good stuff as usual; reminds me I need to get back to reading on NVG stuff in general and finishing my NVG article in specific! I'll have to come back by this in the future whenever I shift focus to Tib Sun era equipment, as that is definitely a TL9+ setting.

    1. He's a post that Anthony from the forums on the limitations of night vision that you might find useful

      His other light base articles are good reads as well.

      In general I agree with him that GURPS is a little too generous with the levels of night vision it grants NVG's but I left things RAW in my post just because it's already information dense enough as it is.

    2. Cheers! I will give that a read at some point before getting back on the project. These kinds of equipment I figure would be well on the less interesting side of things like more guns and body armor to most players, especially considering I'm writing to a specific era's device. I just need to illustrate my article on the M17 gas mask (yeah, really...) and I've been working on-and-off for one on the ALICE field kit system for a while now as well that needs to get out into the light - both of those are going to be *super* niche, I think!