Horizontal Coriolis Force: Calculation

To manually calculate horizontal Coriolis deflection, we only need to know the latitude of our position and how long our bullet will be in flight:

(.00007292 rad/s * cos(latitude°)) * (Time of flight) * 1000 = Horizontal deflection in MRADs

 

positive outputs = right deflection                   negative outputs = left deflection

Data collection

Time of flight can be derived in an online ballistics program, or found in the ATragMX under the “MC” button in the top right of the screen. 

Map latitude in Arma 3 does not always correlate with real word locations, this information sometimes not being specified and auto-populating with default Arma values. Assigned map latitude can be determined by connecting a DAGR to an ATragMX and checking the populated “lat” value under the “Target” column. (((or checking a MicroDAGR???)))

Equation limitations

This equation will serve well under most conditions and the small degree of inherent error will not impede operations in target rich environments even in hand with poor atmospheric conditions.

In high value target environments, or when the effects of a single shot must be guaranteed, it should be noted that atmospherics are not considered in the equation, and under extreme examples this additional variable can create relevant error when compounded with other unknowns. As air resistance increases (typically due to lower temperatures and altitudes, or higher pressures and humidities), our bullet loses its inherited rotational velocity more quickly (see Horizontal Coriolis: Introduction). This increases the horizontal deflection accumulated over time, up to around .05 MRADs at 1000m in unfavorable conditions.

When atmospherics are unfavorable, horizontal Coriolis holds need to increase.