Artillery detection

[Seb3brv78]

To continue on some remarks pointed out in these two subjects :

Artillery use question (https://forums.lnlpublishing.com/threads/artillery-use-question.6030/)
Reconnaissance Capability (https://forums.lnlpublishing.com/threads/reconnaissance-capability.6067/)

We have in some scenarios medium and heavy artillery battalions who, historically, had amongst others a mission of counter-battery. After a little research on the web, I found out there were various means of artillery detection and target acquisition including air reconnaissance (for instance, every US field artillery battalions had L4 Pipe Cub aircrafts organically attached), flash spotting, sound ranging, and even radar particularly efficient against mortar fire (though if I understood well, it was in service rather at the end of the war).

Some of the pages I found interesting:

• http://ww2f.com/threads/counterbattery-fire-in-ww2.20142/
• https://armyhistory.org/u-s-and-german-field-artillery-in-world-war-ii-a-comparison/
• https://apps.dtic.mil/dtic/tr/fulltext/u2/a242118.pdf (master thesis about US Field artillery doctrine between WW1 and WW2)
• https://en.wikipedia.org/wiki/Artillery_sound_ranging#World_War_II

Now, I presume that having reco flights or even some kind of intel from airplanes used during airstrikes might be difficult to implement at this stage of development. However, I was wondering if being able to see the origin of a bombardment could be a way of rendering the intel available through artillery dectection.

To develop on this point, it happens during the game to see the human side units being fired (direct fire) without any enemy unit detected and displayed on the map. When it occurs, I try to determine an approximate origin of fire to order a bombardment. In my mind, making bombardment "shots" (?) visible would play the role of artillery detection in the game and allow to order counter-battery, however rough and approximate.

Going further, it could be a way to gain more balance in the game, making the AI a more challenging opponent (on the artillery side). Basically, I imagine a system of artillery detection where the longer and the more an artillery unit carries out bombardment missions from the same location, the more intel it gradually gives away: approximate origin of fire -> approximate position of the unit -> more and more precise location -> number of guns/mortars, caliber. After, there is the matter to enable the AI to exploit this intel and to give high priority to these targets.

 

[GoodGuy]

... and even radar particularly efficient against mortar fire (though if I understood well, it was in service rather at the end of the war).

The SCR-584 was used in Anzio, shortly after the Normandy landings in France and along the flight paths of the German flying bombs, as part of search/tracking systems that controlled AA guns (automatic gun laying).

A prototype was installed on Lexington in 1943, the Navy's production version on Bunker Hill and Enterprise.
Auto-track/-search had a range of 18.2 miles (ie. for auto-tracking of enemy bombers or flying bombs), Potentiometer data mode (artillery control) a range of 15.9 miles, while the regular search offered a range of 39 miles. German vehicles on the ground were picked up in Italy at a distance of around 26 km on one occasion, supposedly. The wiki article doesn't offer any source for that, though.
I knew that the US military discovered that some enemy shells/trajectories could be tracked, so I'd imagine that the info about this finding spread quickly among units/crews who were operating the very first systems.
The US stationed numbers of these systems in England, as gun-laying systems for AA guns. They were quite successful.

I do believe that the delopers had the AA gun-laying and tracking role in mind, primarily, and not a counterbattery role, though, as the British had worked on AA auto-tracking from the get-go, before they shared the magnetron technology with the US.
I'd consider the ability to locate enemy mortar/arty batteries with radar to be a byproduct. It seems that mortar detection appeared to be way easier, due to the higher angles (and respective longer flights/low velocities). Given the historical arty ranges, sound detection was probably almost as effective (for counterbatt. missions) as radar detection, regarding detection range.

Interesting appliance, though:
https://en.wikipedia.org/wiki/SCR-584_radar

Sound "ranging": This was triangulation - where the time-of-arrival difference still had to be used to compute the location/source point, basically, so I for one don't call it ranging, whereas radar operators could see the position - and even measure the distance - on the displays from where an arty shell was fired (well, more or less, one or another sec after the shell had left the barrel, which gave the operator a pretty good idea where the gun position must have been located when tracing the trajectory) without having to compute anything. The low RPM of the system probably still made tracing (back) challenging, though, hence the difficulties with tracing curved trajectories.

Now, I presume that having reco flights or even some kind of intel from airplanes used during airstrikes might be difficult to implement at this stage of development. However, I was wondering if being able to see the origin of a bombardment could be a way of rendering the intel available through artillery dectection.

Nice idea.
For instance, the German Army introduced their light metering units 1915, after having experimented with the technology in artillery sections called "measuring plan troops" (actually employed as divisional asset + responsible for measuring and creating arty grids). They created 101 light metering units, the number rose to 160 until the end of the war.
Sound measuring units were introduced in 1916, 110 units were created. They also eperimented with a few combined units, where they combined these 2 methods for counterbattery missions.
The Germans maintained such units all through WWII. And there were all sorts of scout planes.
So, yes, the ability was there.

To develop on this point, it happens during the game to see the human side units being fired (direct fire) without any enemy unit detected and displayed on the map. When it occurs, I try to determine an approximate origin of fire to order a bombardment. In my mind, making bombardment "shots" (?) visible would play the role of artillery detection in the game and allow to order counter-battery, however rough and approximate.
Going further, it could be a way to gain more balance in the game, making the AI a more challenging opponent (on the artillery side). Basically, I imagine a system of artillery detection where the longer and the more an artillery unit carries out bombardment missions from the same location, the more intel it gradually gives away: approximate origin of fire -> approximate position of the unit -> more and more precise location -> number of guns/mortars, caliber. After, there is the matter to enable the AI to exploit this intel and to give high priority to these targets.

Very interesting idea.

Visible bombardment shots: You mean tracers. There are tracers in the game already, for direct fire (friendlies and enemies) and for your own arty. The tracers of your own arty pieces are completely rendered, you can watch them going from your unit to the bombardment location (well, last time I checked, at least).
The question is, do we want to see enemy arty tracers?
This would basically remove the fog of war from all enemy arty pieces, eventually.

I'd rather have a number of locally attached (and checked for historical accuracy) say detection platoons, which can trace enemy arty shots within a certain range and the unit has to be stationary (say dug in), to simulate the time for setting up the microphones, laying wires, etc. etc.
IIRC, the German sound detection systems had max ranges of ~15 km, I'd have to check for the exact ranges. After continous losses from counterbattery fire during 1941/1942, the Russians then often moved their arty pieces - where the main models had somewhat higher ranges than their German counterparts - to points slightly (or even completely) outside German artillery and detection ranges. They could then still reach the MBL on fixed fronts, but not the hinterland. Since their 120-mm mortars had relatively high ranges (6 km) they could still provide bombardment support for frontline units.
The mortars could not be detected by German light metering units and the sound detectability of mortars was significantly lower than the detectab. of artillery guns. The range and the accuracy of these Russian mortars made the Germans copy the mortars and produce large batches of them (~ 8,461 , 1943 until the end of the war).

Not every unit had sound measuring capabilities, though, at least in the German army.
Artillery Observer Bns/elements used to be the only units holding such detection troops.

In order to change this, and to cater for situations where arty pieces could not be detected visually (by plane, fast obs elements on the ground, etc) because there was less smoke/no flash - means especially to counter the Russian 120-mm mortars - the Germans started to establish "sound measuring troops" for all (that was the plan, at least) infantry gun coys in 1942. These guys belonged to the infantry branch, they were not artillerymen - unlike their big "brothers" employed in sound measuring batteries of artillery Observation Bns. The branches in such Observation Bns:
HQ, measurement battery (most likely for the creation of grids, drawing of terrain layouts, creation of detailed/revised map material), sound detection battery, light metering battery and the weather platoon.

Until the end of the war, the Germans created 160 sound detection troops (for the inf gun coys).
3 types were to be created:
a) Flachland (for flat terrain) (22 men: 1 officer, 3 NCOs, 18 men)
b) motorisiert (motorized) (20 men: 1 officer, 3 NCOs, 16 men)
c) Gebirge (mountain) (22 men: 1, 3, 18)

15 units had been established by February 1, 1943. Between late 1942 and late 1943 around 38 units were established, trained and attached to field units. A number of these units were then also attached to Panzergrenadier Divisions, to Volksgrenadier divisions, to Waffen SS units, Mountain Jäger-Divisions (Ski-Jäger-Division) and even to a Gr. Wf. Battalion (Gr. Wf. Bn 18), means also to units that didn't even have inf guns attached, but mortars or SPGs. Obviously, some of these troops also assisted Panzer-Artillery units (SPGs) in Panzergrenadier divisions and arty pieces in Jäger-Regiments.
The units sent to be attached to SS units in 1944 and 1945 were all Army troops who were then forced to become SS troops, basically.

 

[Lobsterr]

https://en.wikipedia.org/wiki/Artillery_sound_ranging
https://en.wikipedia.org/wiki/Flash_spotting
https://en.wikipedia.org/wiki/Counter-battery_fire

 

[Seb3brv78]

Visible bombardment shots: You mean tracers. There are tracers in the game already, for direct fire (friendlies and enemies) and for your own arty. The tracers of your own arty pieces are completely rendered, you can watch them going from your unit to the bombardment location (well, last time I checked, at least).

Yes, that's what I meant thank you!

The question is, do we want to see enemy arty tracers?
This would basically remove the fog of war from all enemy arty pieces, eventually.

I'd rather have a number of locally attached (and checked for historical accuracy) say detection platoons, which can trace enemy arty shots within a certain range and the unit has to be stationary (say dug in), to simulate the time for setting up the microphones, laying wires, etc. etc.
IIRC, the German sound detection systems had max ranges of ~15 km, I'd have to check for the exact ranges.

Eventually, yes, if they stayed in the same place long enough. In my idea, the opposite would also eventually be true for our own arty units being visible to the enemy AI.

However, I believe they are various parameters that could hamper a total efficiency of artillery detection, thus preventing the fog of war to be completely lifted. Some research should be carried out to study more precisely these parameters, but as far as I could read, it looks like they would include: a limited range (as you said), the nature of the terrain, the relief itself (unsure), the weather, the time of the day (as night time is necessary for flash spotting). I found some literature about the subject, I will try to go into it a little more throughly.

I would like to add some personal remarks/observations on the hypothetical development of such capacities in the game:

1. I'd rather adopt a solution where artillery detection would be invisibly integrated in the game: it would be available through the presence on map of certain units, say artillery battalions or gun companies (on the German side for instance). The forward units on the battlefield, as soon as they are dug in (or deployed, perhaps), would serve as anchors for invisible "forward observers", and the detection range would start from these units. But it's possible that your solution of visible detection units could be more viable; I found out that the British had detection units, but apparently attached only at the higher echelon of the AGRA (Army Group Royal Artillery).
2. If the detection range should be limited, it is my belief that aerial observation should better be left out of artillery detection capacities.
3. The only way to conserve a proper balance between the human player and the AI is that the latter can use and act on the intel provided by artillery detection, otherwise it's worthless.

 

[GoodGuy]

Yes, that's what I meant thank you!
.

1. If the detection range should be limited, it is my belief that aerial observation should better be left out of artillery detection capacities.
2. The only way to conserve a proper balance between the human player and the AI is that the latter can use and act on the intel provided by artillery detection, otherwise it's worthless.

If you render detection units, then you give the enemy the opportunity to say overrun/destroy such units. For instance, 15-20 km weren't that much for fast recon Bns or tank groups that exploited/penetrated enemy flanks. If friendly intel didn't catch up on such events, detection/arty units could be in deep trouble. This would create a whole new series of tactical/strategical opportunities for the player. If you reduce the detection pool of the enemy, then you can gain an advantage. The same goes for rendering supply columns. Even in modern times, with GPS and modern comm. channels, separated trail convoy elements get ambushed/captured (eg. in Iraq, 2003, 507th Maintenance Coy taking several wrong turns near Nasiriyah, which led them into the city, as the map display/info of the area was not detailed enough to bypass the city - which was the actual order, let alone to navigate through the city).