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DACS App Note

Using Model Builder Software Modules (#24)

What do we mean by a "radio environment"?

This is still sometimes a source of confusion for some of our first-time customers. The most succinct definition is; "When an operator is equipped with a headset/mic and a control panel in a trainer, his ASTi virtual radio environment will, in all material respects, duplicate the effects that he would experience in a real life situation with no modeling required from the host simulation computer."

But doesn't that imply that even if there were no host simulation computer the operator would still be able to experience an authentic radio communication?

Yes. Although in practice he would probably need an input device like our Hand Held Terminal to control the parameters (squelch, volume, frequency etc.) of his radios if there were no host simulator with radio control panels in it.

Who would he be able to talk to?

Anyone on the DIS network that was in his virtual universe (Exercise ID etc.) who was transmitting on his frequency and who was in range.

So what do I need to do to let my simulator pick up external radio traffic when I connect my simulator to a DIS network?

Nothing. No more than you do when you switch on a real radio.


ASTi's DACs is a processing platform which calculates and generates the parameters of a defined radio environment as it would be perceived by the operator at the headset (i.e. at the audio interface). The DACS simulation capability includes modeling of:

Propagation effects: loss based on frequency, noise based on frequency, jamming noise, terrain occulting.

Modulation mode effects: AM/FM mode differentiation (e.g. signal mixing in AM mode, and 'pick the strongest signal' in FM mode), digital communications.

Radio parameters: transmission bandwidth, antenna gain, kTB noise, maximum AGC, line-of-sight or over the horizon propagation, radio internal noise, transmit power, VOX, PTT, definable filter bandwidths, squelch, volume.

Communications device types modeled: AM, wide-FM, narrow-FM, digital communications, crypto communications, SINGCARS type 3 and type 4 radio models, intercom communications, transmitter, receiver, transceiver, VOR beacon, NDB beacon, DME beacon, TACAN beacon, CW Beacon, Co-located VOR/DME, Co-located VOR/TACAN, Marker tones, pulse streams (definable PRI and PW, Dwell, Random Dwell, Stagger, pulse sequence, pulse step), full or half-duplex.

Audio compression modes: 8 bit mu-law, CECOM CVSD, CCTT CVSD.

Other Features: Full record/playback capability, DIS network support, multi-operator/radio/platform exercise support, the software includes hooks so that nearly all of the features noted above are externally controllable (i.e. controlled based on data from an actual comms panel or host computer).