TTY information lines within Ps

An example of the TTY information lines:

Navg:3,  FIR:1.10 usec (259 Taps), Edge:0.100, Win: Tukey,
BW:0.889 MHz, NEBW: 0.980 MHz, DC-Gain: Unknown 
 
Freq:59.966 MHz, Pwr:-12.76 dBm, PkBrstPwr(PriRx: -7.12 dBm,
SecRx: -7.10 dBm), RxLoss:1.627 dB, fltMtch:0.215 dB,
brstEg:0.05896 nJ, fltBrstEg:0.04054 nJ, AFC:28.22% [1822] (Locked)
Ps TTY information lines
Information line Description
Navg The number of burst sample spectra that are averaged together prior to plotting. Larger amounts of averaging increase the ability to see subtle spectral components, but the display updates more slowly.
FIR Indicates the length of the impulse response of the passband FIR filter, and hence, the duration of the burst pulse sample window. The length is reported both as a number of taps, and as a time duration in microseconds. If using an idealized matched filter this value should be the burst pulse length.

See TTY information lines in Pb.
Edge Fractional percentage of edge points being used within the windowing function
Win Name of the windowing function in use
BW The 3 dB bandwidth of the passband filter. This is the complete width of the passband from the lower frequency edge to upper frequency edge. Note that the filters center frequency is fixed at the radars intermediate frequency, as chosen in the Mb setup command.
NEBW Noise Equivalent Bandwidth (NEBW9 is the bandwidth of the rectangular window which would have the same amount of power pass through as the current filter. If the windowing function selected is rectangular, then the NEBW and BW values should match.
DC-Gain

The filter's response to DC (zero frequency) input.

The value is a negative number in decibels, or the word ZERO if the filter has a true zero at DC. The filters DC gain should be kept at a minimum so that fixed offsets in the A/D converters do not propagate into the synthesized I and Q values.
PkBrstPwr The maximum power in a burst pulse. If burst pulse is configured to be taken from Ch. 5 of the IFDR, then PriRx and SecRx display the same value (Ch. 5). If burst pulse is configured to be taken separately for H and V polarizations, PriRx and SecRx display the burst power values of Ch. 1 and Ch. 2, respectively. Ch. 1 is typically used for H polarization, and Ch. 2 for V polarization.
rxLoss

The filter loss is a measure of how much information (or energy loss) is discarded by the filter. See Computing filter loss.
fltMtch This value is displayed for debugging purposes and does not have any direct physical meaning.
brstEg The energy of the full burst sample window.
fltBrstEg The energy of the filtered burst.
AFC

The level and status of the AFC voltage at the IFDR module. The number is the present output level in D-Units ranging from 100 to +100. The shorter % symbol is used since percentage units correspond in a natural way to the D- Units.

An additional number in square brackets are printed to the right of the AFC level to show the encoded bit pattern which corresponds to that level. This appears when RVP10 detects a special digital format. That is, when the back panel phase-out lines have been configured for AFC, or when any of the following are not true: a) the low and high numeric AFC span is -32768 ... +32767, b) the uplink is enabled, c) the uplink format is binary, and d) pinmap protocol is OFF. Binary format is printed in base-10, BCD format is printed in Hex, and 8B4D format is printed with the low 16-bits (four BCD digits) in Hex and the upper bits in base-10.

The AFC modes shown to the right of the numerical value(s), and can take the following states:

  • (Disabled)

    Indicates that neither AFC nor MFC are enabled. The output voltage remains fixed at 0% (center of its range).

  • (Manual)

    Manual Frequency Control (MFC) is overriding AFC. The U and D commands can be used to slew the voltage up and down.

If any of the following states appears, it implies that AFC is enabled and that MFC is disabled:

  • (NoBurst)

    The energy in the burst is below the minimum energy threshold for a valid pulse. The AFC loop remains idle.

  • (Wait)

    The burst pulse has become valid just recently, but the AFC loop is idle until the transmitter stabilizes.

  • (Track)

    The burst pulse is valid, and the AFC loop is tracking in order to bring the burst frequency within the inner hysteresis limits.

  • (Locked)

    The burst pulse is valid and the AFC loop is locked. The burst frequency is now within the outer hysteresis limits and has previously been within the inner limits while tracking. This is the stable operational mode in which data acquisition should take place.

PkBrstPwr, rxLoss, fltMtch, brstEg, and fltBrstEg are displayed if the overall burst power exceeds the minimum valid burst threshold set in the Mb command. (It would not be possible to compute these values when the burst waveform is missing.) These values are computed from the current channel, indicated in the IF field of the information line (for example: IF: Ch. 1).