Tactical Visibility and Detection Using Observation

[swaghauler]

Originally Posted by CDAT

The man sized I can not say, 1000 meters there sounds about right to me (maybe to far to be honest with any camo). As for vehicles it was a crew effort, driver and Loader normally with no magnification, gunner with the X3 power, and tank commander sometimes with bino's, some times with the Mk. I Eye. If we did not spot them (not ID, but spot) them by about 2500-3000 we were dead, as in they would kill us. We were expected to engage them by that range if not a bit further. Max effective range (ballistic computer stopped working) was 4000 meters, but it was almost imposable to ID them at that range. Now all of this is terrain dependent if there is woods much shorter ranges, but I spent most of my time in Tanks in the desert so not much terrain for an armored vehicle to hide in. One other thing to remember tanks work in platoons and each tank had it sector to search so you are not searching 360 degrees, more like 100-120 (with overlap). When one of the guys with out magnification would see something that did not look right they would call it out and then one of the guys with magnification would take a second look at it. So what I am getting at is I would say that the 2500-3000 meters is the base line for spotting a vehicle in the open.

I wasn't going to exceed the Twilight imposed maximum range of 3000 meters on the Encounter Ranges Chart but you do make a good argument.
I guess the best way to do it would be to introduce a new Encounter Range.

Very Open Range: this encompasses such terrain as the American Plains, The deserts of Iraq, The African Serengeti and large bodies of open water. Range is 1D10 X 500 meters. This encounter range extends to the horizon.

I have made adjustments to my previous rules posts to reflect this new maximum encounter range.

[swaghauler]

Sometimes it is necessary to know the range to an object or person during play. I use the following rules to determine the range of an object using Stadiametric Rangefinders, Laser Rangefinders, or even the "MK1 Eyeball."

Stadiametric Rangefinders: These rangefinders use either vertical or horizontal lines to determine the range of an object of "Known Size." These rangefinders are "target specific," being designed for either vehicles or people. In the vast majority of Stadiametric Rangefinders, the user either "sandwiches the target" between two horizontal lines or "chokes the target" between two vertical lines to determine the range. A few (especially scopes) will use precisely sized circles, mildots, or "hashmarks"/chevrons for range estimation.
When using a Stadiametric Rangefinder, the player determines his Observation Skill roll by using The Chance of Vehicle Detection Chart (even for people). This represents the fact that Stadiametric Rangefinders become progressively more inaccurate as range increases. The following conditions will also impact the character's chance of successfully ranging the object in question:
-Using a Stadiametric Rangefinder of the wrong "target type" (ie using a rangefinder configured for a vehicle to range a man and vice versa): 1 Level more Difficult.
-Light fog/snow/smoke or heavy rain: 1 Level more Difficult.
-Heavy fog/smoke or snow: 2 Levels more Difficult.
-Target movement: 1 Level more Difficult per speed level (1 at safe speed, 2 at 2 x safe speed, 3 at 3 x safe speed).

Laser Rangefinders: Using a hand-held Laser Rangefinder is an Easy (2xSkill) task of Observation, REGARDLESS OF RANGE, so long as the Laser Rangefinder has the range to reach the target.
The effectiveness of Laser Rangefinders can be affected by the following conditions;
-Laser Rangefinders are blocked by White Phosphorous OR Dual Spectrum Smoke. They are also blocked by the aerosol from the Shorta Countermeasures system.
-Heavy snow or rain can reduce the Skill Roll to Routine (1.5xSkill).
-Laser Absorbing Paint will cause a penalty of 1 point to the skill roll (a roll of 14 becomes 15).

"Improvised Ranging Devices:" These devices allow you to measure an object of known size with a device that has a known or measurable "reference line." You then put your "Improvised Ranging Device's" reference line over the target you wish to range. Simple Geometry then allows you to determine the range. Examples of "Improvised Ranging Devices" include but are not limited to Lensatic Compasses with sighting systems that have crosshairs, Scopes without rangefinders, Artillery/Mortar Reference Stakes, Plumbobs, and even Sextants used in navigation. Any device with at least a known vertical reference line can be used. The chance of properly ranging a target using this method is the same as trying to IDENTIFY A TARGET off of the Observation Chart (you may substitute Forward Observer/Fire Direction for Observation). You must use the appropriate chart (vehicle-sized or man-sized) as well. All of the conditions that apply for Stadiametric Ranging Apply here with one exception, YOU CANNOT USE THIS METHOD ON A MOVING TARGET.

The "MK1 Eyeball" Method of Ranging: It is possible for experienced observers to estimate range right off the top of their head. The Character MUST roll on the appropriate Target Detection Chart and ALL of the Conditions for Stadiametric Ranging apply. The Base Skill chance for this task is TWO LEVELS GREATER THAN THE DETECTION CHANCE IF USING OBSERVATION. Players may use Forward Observer/Fire Direction in lieu of their Observation Skill. Using Forward Observer/Fire Direction is ONLY ONE LEVEL MORE DIFFICULT THAN THE DETECTION CHANCE.

Why Range a Target?
Ranging a target gives the following bonuses/effects in my game:
1. A bonus of 1 on all Small Arms and Heavy Weapon's To hit rolls (a 15 becomes a 14). IF THE WEAPON IN QUESTION HAS AN OPTIC OR A SIGHT WITH RANGING ADJUSTMENTS ON IT (H&K drum sights, AK ladder sight)
2. Reduces the initial skill difficulty of Indirect Fire (Difficult becomes Average).
3. Gives the EXACT RANGE to a target (otherwise, the target may be 1D10 meters closer (1-5) OR further (6-10) PER RANGE BAND AFTER SHORT RANGE than the players think the target really is. This can drastically affect ambushes and firefights.
4. Allows the character to determine that a target is within the range of a given heavy weapon, IED, or other devices with a limited range during play.

WallShadow, I hope these added rules will help you out. As always, use what you will and ignore the rest.

Swag.

[WallShadow]

Originally Posted by swaghauler

SNIP--
WallShadow, I hope these added rules will help you out. As always, use what you will and ignore the rest.
--Swag.

Uh, yeah, sure, thanks. (WOW!!!!!)

BTW, I'm not sure if I missed it but were Ranging stakes (alternately, "when they get abreast of the burned-out Cadillac") mentioned for static defense situation?

[swaghauler]

Originally Posted by WallShadow

Uh, yeah, sure, thanks. (WOW!!!!!)

BTW, I'm not sure if I missed it but were Ranging stakes (alternately, "when they get abreast of the burned-out Cadillac") mentioned for static defense situation?

Ranging stakes are an "Improvised Ranging Device" under these rules. I have added them to the rules above.

In a "Static Defense," a good unit will "Pre-Register" every terrain feature within their sector of fire. The Deflection (horizontal location in mills) and Quadrant (vertical location in mills) of every object will be recorded for very accurate fire. EVERY DEFENDER will have access to the EXACT RANGE of every object in their field of fire. There will be "Short Orders" (pre-determined/arranged fire missions) for the artillery in place. It will take only about 5 to 10 seconds to give out a "Short Order," Compared to 30 seconds for a normal fire mission.
I allow AT LEAST ONE Difficulty level easier (and sometimes TWO LEVELS easier) for all first round artillery fire because of this (both direct and indirect fire). All heavy weapons and tripod mounted MGs will have the ranging bonuses above.
In addition, any terrain feature that provides protection to attackers from the defender's fields of fire (particularly direct fire) is likely to be "booby-trapped" with mines, barbed wire, punji sticks, or even wild animals like poisonous snakes in ditches and pits.

When you consider all of the above are just the most basic precautions a defender may take; You can imagine how "tough a nut to crack" a place like Krakow (that makes munitions and land mines) would be.

[swaghauler]

Here are my Observation Tables for Range AND Lighting Conditions. Take a look and let me know what you think. Please note that I use a different set of skill modifiers and I will list them for you. My lighting conditions are as follows;

Daylight: Self explanatory.

Dusk/Dawn: The period of time DIRECTLY AFTER the sun has set (when the sky is still light but the shadows are deepening) and BEFORE the Sun has risen in the sky (but that sky is still very light). This could also be a very well lit city street, like the main business strip of a large city.

Full Moon: The Moon is high and bright in the sky. Also could be a normal Western city street or US small town main street.

Half Moon: A half Moon with stars to boot. Could also be a full Moon in overcast conditions.

Partial Moon: Either a quarter Moon or an overcast half moon. Could also be a Post-Exchange city street using torch/lamp light.

Starlight: Bright stars with a new Moon. Candlelight style interior lighting.

Overcast: No visible stars. Could also be starlight through an overhead cover such as woods or a hole in a roof.

Here are my tables....

Chance Of Detecting A Man-Sized Object By Range & Light Level:

Difficulty Level:..........Daylight:... Dusk/Dawn:... Full Moon:... 1/2 Moon:... Partial:.... Starlight:.... Overcast:
Impossible (Skillx0.1): .... 1000m........ 700m............. 500m........... 300m...........200m........ 100m............. 50m
Formidable (Skillx0.25): ... 700m ........ 500m ............ 300m .......... 200m ........ 100m ......... 50m ............ 25m
Difficult (Skillx0.5): ......... 500m ........ 300m ............ 200m .......... 100m ......... 50m .......... 25m ............ 10m
Average (Skill): .............. 300m ........ 200m ............ 100m ........... 50m .......... 25m .......... 10m ............. 5m
Routine (Skillx1.5): .......... 200m ....... 100m .............. 50m ........... 25m .......... 10m ........... 5m ............. 2m
Easy (Skillx2): ................ 100m ........ 50m ............... 25m ........... 10m ........... 5m ........... 2m .............. 1m

Chance Of Detecting A Vehicle By Range & Light Level:

Difficulty Level: ...........Daylight: .... Dusk/Dawn: .... Full Moon: .... 1/2 Moon: .... Partial: .... Starlight: .... Overcast:
Impossible (Skillx0.1): ..... 5000m ......... 3000m .............. 2000m ........... 1500m ....... 1000m ......... 700m ........... 400m
Formidable (Skilx0.25): .... 3000m ......... 2000m .............. 1500m ........... 1000m ........ 700m ........... 400m .......... 200m
Difficult (Skillx0.5): .......... 2000m ......... 1500m .............. 1000m ........... 700m ......... 400m ........... 200m .......... 100m
Average (Skill): ............... 1500m ......... 1000m ............... 700m ............ 400m ......... 200m ........... 100m ........... 50m
Routine (Skillx1.5): ........... 1000m ........ 700m ................. 400m ............ 200m ......... 100m ............ 50m ............ 25m
Easy (Skillx2): .................. 700m ......... 400m ................. 200m ............ 100m ........... 50m ............ 25m ............ 10m


These are my initial ranges based on light level. Please feel free to comment.

As always, use what you will and ignore the rest.

Swag.

[swaghauler]

I know that the normal method of doing night vision is to just give it a range and you simply cannot see farther than this limit. I'm interested in treating NV Goggles somewhat more transparently. My thought is to give various Generations of NV Goggles "bonus shifts" on the Observation and Spotting Table based on lighting conditions. My idea would be to list the light levels that you can use the NV Goggles in and what improvements in detection they give while worn. Otherwise, how would they affect the player's skills while in use? Here are some stats for the various generations of night vision intensifiers:

Generation I NV (IR Illuminator needed): This the Russian standard until the late 80's (and the T72/T80).

Resolution (Lines per mm): 20 to 25
Signal-to-Noise Ration (the higher the better): 8 to 10
Tube Life (hours of operation): 1500 hrs

a 75m maximum range of normal visual recognition is commonly listed. I would say that driving, shooting, or operating hand tools would be TWO LEVELS more difficult. Riding a motorcycle, reading and flying are impossible to do.
Chances of Detection:
Daylight: NO
Dusk/Dawn: NO
Full Moon: treat as Dusk/Dawn
Half Moon: treat as Full Moon
Partial Moonlight: treat as Half Moonlight
Starlight: treat as Partial Moonlight
Overcast: treat as Starlight

Generation II NV: This is the Russian standard from the mid 80's until the late 90's. It is also a Police Standard until the late 90's.

Resolution (lines per mm): 40 to 45
Signal-to-Noise Ratio (higher is better): 16 to 20
Tube Life (hours of operation): 5,000 hrs

A 200m maximum range of normal visual recognition is commonly listed. I would say that driving, shooting, or normal operation of tools is ONE LEVEL more difficult. Riding a motorcycle or reading would be TWO LEVELS more difficult. Flying would be THREE LEVELS more difficult.
Chances of Detection:
Daylight: NO
Dusk/Dawn: NO
Full Moon: treat as Dusk/Dawn
Half Moon: treat as Full Moon
Partial Moonlight: treat as Half Moon
Starlight: treat as Partial Moon BUT requires IR illuminator
Overcast: treat as Starlight BUT requires IR illuminator

Generation II+ NV: These are "reconditioned" GEN II NV Goggles fitted with GEN III tubes but still using the GEN II imager. Pioneered by Russia but commonly used by American Hog hunters in the late 90's.

Resolution (lines per mm): 45 to 54
Signal-to-Noise Ratio (higher is better): 16 to 22
Tube Life (hrs of operation): 10,000 hrs

A 300m maximum range of normal visual recognition is commonly listed. Driving and shooting are ONE LEVEL more difficult. Flying and reading are TWO LEVELS more difficult.
Chances of Detection:
Daylight: NO
Dusk/Dawn: NO
Full Moon: treat as Daylight
Half Moon: treat as Dusk/Dawn
Partial Moonlight: treat as Full Moon
Starlight: treat as Half Moon
Overcast: treat as Partial Moon

Generation III NV (including 90's Autogated GEN III): The most common form of Western night vision from the late 80's until the mid to late 90's. Russia caught up to the US with GEN III night vision on the T90 in the late 90's. Autogated night vision would be a Western/NATO exclusive during the Twilight War.

Resolution (lines per mm): 64 to 72
Signal-to-Noise Ratio (higher is better): 20 to 24
Tube Life (hrs of operation): 10,000 hrs (Autogated is 5,000 hrs)

A 350m range of normal vision is often quoted for GEN III NV. Driving, reading, and shooting all suffer a penalty of 1 on the skill roll (a 14 becomes a 15). Flying is ONE LEVEL more difficult due to the lack of depth perception.
Chances of Detection:
Daylight: NO
Dusk/Dawn: NO (GEN III Autogated is YES as Daylight)
Full Moon: treat as Daylight
Half Moon: treat as Dusk/Dawn
Partial Moon: treat as Full Moon
Starlight: treat as Half Moon
Overcast: treat as Partial Moon

Generation III+ NV Autogated: These 21st Century goggles have a few improvements over traditional GEN III goggles. It uses a white on white technology (as opposed to the green hue more commonly seen) for improved contrast as well as REAL visual depth perception (for flying). There are no penalties when using these NV goggles.

Resolution (lines per mm): 76+
Signal-to-Noise Ratio (higher is better): 24 to 30
Tube Life (hrs of operation): 10,000 hrs

a detection range of 500m is commonly listed for these. As stated above, there are no skill penalties associated with these goggles.
Chances of Detection:
Daylight: NO
Dusk/Dawn: treat as Daylight
Full Moon: treat as Daylight
Half Moon: treat as Dusk/Dawn
Partial Moon: treat as Full Moon
Starlight: treat as Half Moon
Overcast: treat as Partial Moonlight

Generation IV NV: I have no definitive info on the Fusion sights other than they combine thermal and starlight into one device.

Let me know if this is a good start to night vision. CDAT, Army Sgt, I know you have more experience here. your opinions would be appreciated.