|
PRED-RF Results (RF Agility)
RF
Agility Prediction can now be combined with PRI prediction
capabilities giving your system the ability to counter both PRI and
RF agile threats. In order for an ECM system to create
in-bound false targets versus an RF agile threat it is necessary
that both the radio frequency of the incoming radar pulse and its
time of arrival be predicted.
The
PRED series can be used with a VCO to enable an ECM system to create
up-range and cover-pulse technique greatly increasing your
capabilities against RF agile threats. A digital word indicating the
frequency of the next pulse is issued halfway through the PRI - this
allows both down-range and up-range false targets to be generated.
Specialized techniques may also be used with DRFM's to obtain an RF
agility capability.
The RF
prediction channel is designed to integrate with the PRED PRI
predictor. The combination of PRI and RF agility prediction
gives the jammer the ability to produce precise point targets in
both the time and frequency domains. In a typical system
architecture, the RF prediction channel complements the remaining
PRI prediction channels for a well rounded ECM capability.
Click here for larger
image
Click here for larger image
A
parameter critical to the ability to successfully predict many
modulated RF patterns is the ability to correctly predict the time
of arrival of the pulse. This is solved using the PRED PRI
prediction. With accurate PRI prediction, the predicted RF
values closely match the actual RF observed despite the fact that
sinusoidally modulated RF measurements appear to be random due to
the nature of their generation (e.g. spin tuned magnetron).
One way
of showing the effectiveness of the PRED RF Agility prediction is to
make a histogram of the RF predictions. This shows the
distribution of the predictions with respect to the input DFD error.
The following charts show the prediction distribution for 0, 1.5 and
3 MHz of DFD error. In these examples the DFD resolution is 1
MHz. In this
example the signal is a sinusoidal RF with:
As
expected, as the input error increases so does the prediction error
- very little extra error is added by the prediction.
DFD Error = 0 (ideal case) - PRED adds only 1 LSB of error
DFD Error = 1.5 MHz - PRED adds about 1 LSB error above DFD error
DFD Error = 3 MHz - PRED adds about 3 LSB errors above DFD error
|
