Local particle effects from mods

[super-truite]

I am looking at the content of this mod:

The code to describe the particle emmiters looks like this :
 

Class_name = "CStaticExplosions"

//Modified by TemplarGFX

RenderID=-1        //-1 to explode everywhere

//Explosions
[Emitter]
    P=0.27
    Object="LuaScripts\WorldObjects\Emitters\DummyGroundExpl_0.txt"
    WaterObject="LuaScripts\WorldObjects\TemplarGFX\templar_no_water.txt"
    Alt=0
    Range=800,8000
[end]

Is there some doc about the different values ? 
I guess that Object/WaterObject are links to files that describe the particle effect tiles and associated sound effects for ground and water surfaces.
P seems to be some kind of probability to trigger the effect, but what is a the time period and area? Is it the probability to trigger it in one second? minute ? per km² ? on the whole map ?

Alt must be the altitude of the effect (could it accept some range ?). 
I do not understand what renderID and Range are?

My wanted use cases:
- local area of the map with dense artillery strikes without having to spawn a lot of artillery + attack area MCUs
- movie-like Flak  without having to spawn a lot of AA guns
The main reason is to get more control of the visual aspect and also for optimization.