Several major vessel systems output EM radiation at detectable levels. MIE (impulse) engines output significant amounts of EM across UV, IR and magnetic bands, for example.

Each emitting system has an EM Output profile which determines how much EM is output at a given power or operating level, across all five EM bands.

Response Profiles

Emitting systems may not have a linear response profile. EM output may be lower at reduced power/output levels but rise much more quickly after a certain power/output level. This simulates the operating characteristics of different systems. Impulse engines, for example, will tend to produce significantly more EM output above a certain power level – an effect referred to as “cavitation”.

Lower, upper and maximum levels are defined along the system’s power/output level, creating response profiles defined by the values between levels. The amount of EM output by the system at a selected power/output level is defined for each band and calculated from the relevant response profile.

Defining EM Output Profiles

Two datapoints are required to define an EM Output Profile.

Power/Output Level Stages

Minimum, lower, upper and maximum power/output levels are defined. This defines the X-axis of the response profile. These are common to all EM output bands.

Between one and three response profile stages can be included, depending on when output changes are required.

If a simple linear response profile is required, only the minimum and maximum values need to be defined.

Two-stage or three-stage response profiles can be created by defining combinations of lower, upper and maximum as needed. If a level is not required (for example, a two-stage response profile that does not include the lower level) it can be defined as zero and the system will ignore it.

Format

Response profiles are stored as JSON

min:

lower:

upper:

max:

numBands:

EM Output per Band

The amount of EM output at each defined stage must be specified for each EM band. If a stage is defined as zero, no EM output is needed. This defines the Y-axis of the response profile.

Format

Each EM band has its own output profile.

emX : {

            min:

            lower:

            upper:

            max:

       }

EM Emitted

For systems other than the main engines, the amount of EM emitted is saved back to the EM Output Profile JSON. The current EM output of all non-engine systems is added together by the emEmissions module and supplied to the Impulse Navigation module, where it is added to the EM output of the engines to give the vessel’s total EM output.

Format

emEmitted: {

                 em1:

                 em2:

                 em3:

                 em4:

                 em5:

            }