* These are used to establish the signal quality for each of the five
* frequencies and two stations.
*/
-#define SYNCNG 0x0001 /* sync below threshold or SNR */
-#define JITRNG 0x0002 /* jitter above threshold */
+#define JITRNG 0x0001 /* jitter above threshold */
+#define SYNCNG 0x0002 /* sync below threshold or SNR */
+#define DATANG 0x0004 /* data below threshold or SNR */
#define SELV 0x0100 /* WWV station select */
#define SELH 0x0200 /* WWVH station select */
*/
struct chan {
int gain; /* audio gain */
+ int errcnt; /* data bit error counter */
+ double noiamp; /* I-channel average noise amplitude */
struct sync wwv; /* wwv station */
struct sync wwvh; /* wwvh station */
};
/*
* More function prototypes
*/
-static void wwv_epoch P((struct peer *, double));
+static void wwv_epoch P((struct peer *));
static void wwv_rf P((struct peer *, double));
static void wwv_endpoc P((struct peer *, double, int));
-static double wwv_rsec P((struct peer *, double));
+static void wwv_rsec P((struct peer *, double));
static void wwv_qrz P((struct peer *, struct sync *,
double));
static void wwv_corr4 P((struct peer *, struct decvec *,
temp = P_TRACE;
#endif
if (peer->ttl != 0)
- up->fd_icom = icom_init("/dev/icom", temp);
+ up->fd_icom = icom_init("/dev/icom", B9600, temp);
#endif /* ICOM */
up->schan = 3;
wwv_qsy(peer, up->schan);
up->phase -= 1.;
} else if (up->phase < - .5) {
up->phase += 1.;
- wwv_epoch(peer, sample);
- wwv_epoch(peer, sample);
+ wwv_rf(peer, sample);
+ wwv_rf(peer, sample);
} else {
- wwv_epoch(peer, sample);
+ wwv_rf(peer, sample);
}
L_ADD(&up->timestamp, &up->tick);
}
-/*
- * wwv_epoch - main loop
- *
- * This routine establishes receiver and transmitter epoch
- * synchronization and determines the data subcarrier pulse length.
- * Receiver synchronization is determined by the minute sync pulse
- * detected in the wwv_rf() routine and the second sync pulse detected
- * in the wwv_epoch() routine. This establishes when to sample the data
- * subcarrier in-phase signal for the maximum level and noise level and
- * when to determine the pulse length. The transmitter second leads the
- * receiver second by the propagation delay, receiver delay and filter
- * delay of this program. It establishes the clock time and implements
- * the sometimes idiosyncratic conventional clock time and civil
- * calendar.
- *
- * Most communications radios use a highpass filter in the audio stages,
- * which can do nasty things to the subcarrier phase relative to the
- * sync pulses. Therefore, the data subcarrier reference phase is
- * disciplined using the hardlimited quadrature-phase signal sampled at
- * the same time as the in-phase signal. The phase tracking loop uses
- * phase adjustments of plus-minus one sample (125 us).
- */
-static void
-wwv_epoch(
- struct peer *peer, /* peer structure pointer */
- double sig /* decompanded rf signal sample */
- )
-{
- static double dpulse; /* data pulse length */
- struct refclockproc *pp;
- struct wwvunit *up;
- struct sync *sp;
- l_fp offset; /* NTP format offset */
- char tbuf[80]; /* monitor buffer */
- double dtemp, etemp;
-
- /*
- * Extract the data and sync signals.
- */
- pp = peer->procptr;
- up = (struct wwvunit *)pp->unitptr;
- wwv_rf(peer, sig);
-
- /*
- * In data mode, scan the second looking for a data pulse. In
- * probe mode, just latch the sync pulse amplitude.
- */
- if (!(up->status & MSYNC) || up->status & SFLAG) {
-
- /*
- * Sample the minute sync pulse amplitude at epoch 800
- * for both the WWV and WWVH stations. This will be used
- * later for channel mitigation.
- */
- if (up->rphase == 800 * MS) {
- sp = &up->mitig[up->achan].wwv;
- sp->synamp = sqrt(sp->amp);
- sp = &up->mitig[up->achan].wwvh;
- sp->synamp = sqrt(sp->amp);
- }
- } else {
-
- /*
- * Estimate the noise level by integrating the I-channel
- * energy at epoch 30 ms.
- */
- if (up->rphase == 30 * MS) {
- up->noiamp += (up->irig - up->noiamp) /
- (MINAVG << up->avgint);
-
- /*
- * Strobe the peak I-channel data signal at epoch 200
- * ms. Compute the SNR and adjust the 100-Hz reference
- * oscillator phase using the Q-channel data signal at
- * that epoch. Save the envelope amplitude for the probe
- * channel.
- */
- } else if (up->rphase == 200 * MS) {
- up->sigamp = up->irig;
- if (up->sigamp < 0)
- up->sigamp = 0;
- up->datsnr = wwv_snr(up->sigamp, up->noiamp);
- up->datpha = up->qrig / (MINAVG << up->avgint);
- if (up->datpha >= 0) {
- up->datapt++;
- if (up->datapt >= 80)
- up->datapt -= 80;
- } else {
- up->datapt--;
- if (up->datapt < 0)
- up->datapt += 80;
- }
-
- /*
- * The slice level is set half way between the peak
- * signal and noise levels. Strobe the negative zero
- * crossing after epoch 200 ms and record the epoch at
- * that time. This defines the length of the data pulse,
- * which will later be converted into scaled bit
- * probabilities.
- */
- } else if (up->rphase > 200 * MS) {
- dtemp = (up->sigamp + up->noiamp) / 2;
- if (up->irig < dtemp && dpulse == 0)
- dpulse = up->rphase;
- }
- }
-
- /*
- * At the end of the transmitter second, crank the clock state
- * machine. Note we have to be careful to set the transmitter
- * epoch at the same time as the receiver epoch to be sure the
- * right propagation delay is used. We don't bother the heavy
- * machinery unless the clock is set.
- */
- up->tphase++;
- if (up->epoch == up->yepoch) {
- wwv_tsec(up);
- up->tphase = 0;
-
- /*
- * Determine the current offset from the time of century
- * and the sample timestamp, but only if the SYNERR
- * alarm has not been raised in the present or previous
- * minute.
- */
- if ((up->status & INSYNC) && (up->alarm & (3 <<
- SYNERR)) == 0) {
- pp->second = up->tsec;
- pp->minute = up->decvec[MN].digit +
- up->decvec[MN + 1].digit * 10;
- pp->hour = up->decvec[HR].digit +
- up->decvec[HR + 1].digit * 10;
- pp->day = up->decvec[DA].digit + up->decvec[DA +
- 1].digit * 10 + up->decvec[DA + 2].digit *
- 100;
- pp->year = up->decvec[YR].digit +
- up->decvec[YR + 1].digit * 10;
- if (pp->year < UTCYEAR)
- pp->year += 2000;
- else
- pp->year += 1900;
-
- /*
- * We have to simulate refclock_process() here,
- * since the fudgetime gets added much earlier
- * than this.
- */
- pp->lastrec = up->timestamp;
- L_CLR(&offset);
- if (!clocktime(pp->day, pp->hour, pp->minute,
- pp->second, GMT, pp->lastrec.l_ui,
- &pp->yearstart, &offset.l_ui))
- up->errflg = CEVNT_BADTIME;
- else
- refclock_process_offset(pp, offset,
- pp->lastrec, 0.);
- }
- }
-
- /*
- * At the end of the receiver second, process the data bit and
- * update the decoding matrix probabilities.
- */
- up->rphase++;
- if (up->epoch == up->repoch) {
- dtemp = wwv_data(up, dpulse);
- etemp = wwv_rsec(peer, dtemp);
- if (up->status & MSYNC && !(up->status & DSYNC)) {
- sprintf(tbuf,
- "wwv3 %2d %04x %5.0f %5.0f %5.0f %5.1f %5.0f %5.0f",
- up->rsec, up->status, up->epomax,
- up->sigamp, up->datpha, up->datsnr, dtemp,
- etemp);
- if (pp->sloppyclockflag & CLK_FLAG4)
- record_clock_stats(&peer->srcadr, tbuf);
-#ifdef DEBUG
- if (debug)
- printf("%s\n", tbuf);
-#endif /* DEBUG */
- }
- wwv_gain(peer);
- up->rphase = dpulse = 0;
- }
-}
-
-
/*
* wwv_rf - process signals and demodulate to baseband
*
static double bpf[9]; /* 1000/1200-Hz bpf delay line */
double syncx; /* bpf output */
static double mf[41]; /* 1000/1200-Hz mf delay line */
- double mfsync = 0; /* mf output */
+ double mfsync; /* mf output */
static int iptr; /* data channel pointer */
static double ibuf[DATSIZ]; /* data I channel delay line */
* multiplying the filtered signal by 100-Hz sine and cosine
* signals, respectively. The data signals are demodulated by
* 170-ms synchronous matched filters to produce the amplitude
- * and phase signals used by the decoder.
+ * and phase signals used by the decoder. Note the correction
+ * due to the propagation delay is necessary for seamless
+ * handover between WWV and WWVH.
*/
- i = up->datapt;
+ i = up->datapt - up->pdelay % 80;
+ if (i < 0)
+ i += 80;
up->datapt = (up->datapt + IN100) % 80;
dtemp = sintab[i] * data / DATSIZ * DGAIN;
up->irig -= ibuf[iptr];
up->watch = up->status = 0;
/*
- * If the second sync amplitude sinks beneath
- * the waves or if it times out, dim the sync
+ * If the second sync times out, dim the sync
* lamp and raises an alarm.
*/
up->swatch++;
- if (up->epomax < STHR || up->swatch > HSPEC) {
+ if (up->swatch > HSPEC) {
up->status &= ~SSYNC;
up->alarm |= 1 << SYNERR;
up->swatch = 0;
mfsync += (mf[2] = mf[1]) * -5.681959e-02;
mfsync += (mf[1] = mf[0]) * -4.833363e-02;
mf[0] = syncx;
+ } else {
+ mfsync = 0;
}
/*
up->epomax = epomax;
epomax = 0;
}
- dtemp = (epobuf[up->epoch] += (mfsync -
- epobuf[up->epoch]) / (MINAVG << up->avgint));
+ dtemp = (epobuf[up->epoch] += (mfsync - epobuf[up->epoch]) /
+ (MINAVG << up->avgint));
if (dtemp > epomax) {
epomax = dtemp;
- epopos = up->epoch - 5 * MS;
+ epopos = up->epoch - up->pdelay - 5 * MS;
if (epopos < 0)
epopos += SECOND;
}
+ if (up->status & MSYNC)
+ wwv_epoch(peer);
}
* If in minute sync, just count the runs up and
* down.
*/
- if (sp->select & (SYNCNG | JITRNG)) {
+ if (sp->select & (DATANG | SYNCNG | JITRNG)) {
if (sp->count > 0)
sp->count--;
} else {
break;
}
sprintf(tbuf,
- "wwv8 %2d %04x %5.0f %s %d %5.0f %5.1f %7ld %7ld %7ld",
- up->rsec, up->status, up->epomax, sp->ident,
- sp->count, sp->sigmax, snr, sp->pos,
- sp->jitter, MOD(sp->pos - up->nepoch -
- SYNSIZ, MINUTE));
+ "wwv8 %-3s %d %5.0f %5.1f %7ld %7ld %7ld",
+ sp->ident, sp->count, sp->sigmax, snr,
+ sp->pos, sp->jitter, MOD(sp->pos -
+ up->nepoch - SYNSIZ, MINUTE));
if (pp->sloppyclockflag & CLK_FLAG4)
record_clock_stats(&peer->srcadr, tbuf);
#ifdef DEBUG
up->status |= SSYNC;
up->swatch = 0;
up->repoch = tepoch;
- up->yepoch = up->repoch - up->pdelay;
+ up->yepoch = up->repoch;
if (up->yepoch < 0)
up->yepoch += SECOND;
}
}
+/*
+ * wwv_epoch - main loop
+ *
+ * This routine establishes receiver and transmitter epoch
+ * synchronization and determines the data subcarrier pulse length.
+ * Receiver synchronization is determined by the minute sync pulse
+ * detected in the wwv_rf() routine and the second sync pulse detected
+ * in the wwv_epoch() routine. This establishes when to sample the data
+ * subcarrier in-phase signal for the maximum level and noise level and
+ * when to determine the pulse length. The transmitter second leads the
+ * receiver second by the propagation delay, receiver delay and filter
+ * delay of this program. It establishes the clock time and implements
+ * the sometimes idiosyncratic conventional clock time and civil
+ * calendar.
+ *
+ * Most communications radios use a highpass filter in the audio stages,
+ * which can do nasty things to the subcarrier phase relative to the
+ * sync pulses. Therefore, the data subcarrier reference phase is
+ * disciplined using the hardlimited quadrature-phase signal sampled at
+ * the same time as the in-phase signal. The phase tracking loop uses
+ * phase adjustments of plus-minus one sample (125 us).
+ */
+static void
+wwv_epoch(
+ struct peer *peer /* peer structure pointer */
+ )
+{
+ static double dpulse; /* data pulse length */
+ struct refclockproc *pp;
+ struct wwvunit *up;
+ struct chan *cp;
+ struct sync *sp;
+ l_fp offset; /* NTP format offset */
+ double dtemp;
+
+ pp = peer->procptr;
+ up = (struct wwvunit *)pp->unitptr;
+
+ /*
+ * Sample the minute sync pulse amplitude at epoch 800 for both
+ * the WWV and WWVH stations. This will be used later for
+ * channel mitigation.
+ */
+ cp = &up->mitig[up->achan];
+ if (up->rphase == 800 * MS) {
+ sp = &cp->wwv;
+ sp->synamp = sqrt(sp->amp);
+ sp = &cp->wwvh;
+ sp->synamp = sqrt(sp->amp);
+ }
+
+ if (up->rsec == 0) {
+ up->sigamp = up->datsnr = 0;
+ } else {
+
+ /*
+ * Estimate the noise level by integrating the I-channel
+ * energy at epoch 30 ms.
+ */
+ if (up->rphase == 30 * MS) {
+ if (!(up->status & SFLAG))
+ up->noiamp += (up->irig - up->noiamp) /
+ (MINAVG << up->avgint);
+ else
+ cp->noiamp += (sqrt(up->irig *
+ up->irig + up->qrig * up->qrig) -
+ cp->noiamp) / 8;
+
+ /*
+ * Strobe the peak I-channel data signal at epoch 200
+ * ms. Compute the SNR and adjust the 100-Hz reference
+ * oscillator phase using the Q-channel data signal at
+ * that epoch. Save the envelope amplitude for the probe
+ * channel.
+ */
+ } else if (up->rphase == 200 * MS) {
+ if (!(up->status & SFLAG)) {
+ up->sigamp = up->irig;
+ if (up->sigamp < 0)
+ up->sigamp = 0;
+ up->datsnr = wwv_snr(up->sigamp,
+ up->noiamp);
+ up->datpha = up->qrig / (MINAVG <<
+ up->avgint);
+ if (up->datpha >= 0) {
+ up->datapt++;
+ if (up->datapt >= 80)
+ up->datapt -= 80;
+ } else {
+ up->datapt--;
+ if (up->datapt < 0)
+ up->datapt += 80;
+ }
+ } else {
+ up->sigamp = sqrt(up->irig * up->irig +
+ up->qrig * up->qrig);
+ up->datsnr = wwv_snr(up->sigamp,
+ cp->noiamp);
+ }
+
+ /*
+ * The slice level is set half way between the peak
+ * signal and noise levels. Strobe the negative zero
+ * crossing after epoch 200 ms and record the epoch at
+ * that time. This defines the length of the data pulse,
+ * which will later be converted into scaled bit
+ * probabilities.
+ */
+ } else if (up->rphase > 200 * MS) {
+ dtemp = (up->sigamp + up->noiamp) / 2;
+ if (up->irig < dtemp && dpulse == 0)
+ dpulse = up->rphase;
+ }
+ }
+
+ /*
+ * At the end of the transmitter second, crank the clock state
+ * machine. Note we have to be careful to set the transmitter
+ * epoch at the same time as the receiver epoch to be sure the
+ * right propagation delay is used. We don't bother the heavy
+ * machinery unless the clock is set.
+ */
+ up->tphase++;
+ if (up->epoch == up->yepoch) {
+ wwv_tsec(up);
+ up->tphase = 0;
+
+ /*
+ * Determine the current offset from the time of century
+ * and the sample timestamp, but only if the SYNERR
+ * alarm has not been raised in the present or previous
+ * minute.
+ */
+ if (!(up->status & SFLAG) && up->status & INSYNC &&
+ (up->alarm & (3 << SYNERR)) == 0) {
+ pp->second = up->tsec;
+ pp->minute = up->decvec[MN].digit +
+ up->decvec[MN + 1].digit * 10;
+ pp->hour = up->decvec[HR].digit +
+ up->decvec[HR + 1].digit * 10;
+ pp->day = up->decvec[DA].digit + up->decvec[DA +
+ 1].digit * 10 + up->decvec[DA + 2].digit *
+ 100;
+ pp->year = up->decvec[YR].digit +
+ up->decvec[YR + 1].digit * 10;
+ if (pp->year < UTCYEAR)
+ pp->year += 2000;
+ else
+ pp->year += 1900;
+
+ /*
+ * We have to simulate refclock_process() here,
+ * since the fudgetime gets added much earlier
+ * than this.
+ */
+ pp->lastrec = up->timestamp;
+ L_CLR(&offset);
+ if (!clocktime(pp->day, pp->hour, pp->minute,
+ pp->second, GMT, pp->lastrec.l_ui,
+ &pp->yearstart, &offset.l_ui))
+ up->errflg = CEVNT_BADTIME;
+ else
+ refclock_process_offset(pp, offset,
+ pp->lastrec, 0.);
+ }
+ }
+
+ /*
+ * At the end of the receiver second, process the data bit and
+ * update the decoding matrix probabilities.
+ */
+ up->rphase++;
+ if (up->epoch == up->repoch) {
+ wwv_rsec(peer, dpulse);
+ wwv_gain(peer);
+ up->rphase = dpulse = 0;
+ }
+}
+
+
/*
* wwv_rsec - process receiver second
*
* transmitter carrier for a few seconds around the leap to avoid icky
* details of transmission format during the leap.
*/
-static double
+static void
wwv_rsec(
struct peer *peer, /* peer structure pointer */
- double bit /* bit probability */
+ double dpulse
)
{
static int iniflg; /* initialization flag */
struct wwvunit *up;
struct chan *cp;
struct sync *sp, *rp;
+ double bit; /* bit likelihood */
char tbuf[80]; /* monitor buffer */
- double rval; /* likelihood value */
int sw, arg, nsec;
pp = peer->procptr;
* seconds state machine.
*/
nsec = up->rsec + 1;
+ bit = wwv_data(up, dpulse);
bitvec[up->rsec] += (bit - bitvec[up->rsec]) / TCONST;
- rval = bitvec[up->rsec];
sw = progx[up->rsec].sw;
arg = progx[up->rsec].arg;
switch (sw) {
break;
/*
- * Compute the max and min of both the sync and data pulses for
- * use later in channel mitigation. The WWV/H format contains
- * data pulses in second 59 (position identifier) and second 1
- * (not used), and a sync pulse in second 0. At the end of
- * second 58, QSY to the probe channel, which rotates over all
- * WWV/H frequencies. At the end of second 59, latch the sync
- * noise and data peak. At the end of second 0, latch the sync
- * peak and data noise. At the end of second 1, latch and
- * average the sync noise and data peak. Finally, QSY back to
- * the data channel.
+ * Probe channel stuff
+ *
+ * The WWV/H format contains data pulses in second 59 (position
+ * identifier) and second 1 (not used), and the minute sync
+ * pulse in second 0. At the end of second 58, we QSYed to the
+ * probe channel, which rotates over all WWV/H frequencies. At
+ * the end of second 59, we latched the sync noise and tested
+ * for data bit error. At the end of second 0, we now latch the
+ * sync peak.
*/
case SYNC2: /* 0 */
cp = &up->mitig[up->achan];
sp->synmax = sp->synamp;
break;
+ /*
+ * At the end of second 1, latch and average the sync noise and
+ * test for data bit error. Set SYNCNG if the sync pulse
+ * amplitude and SNR are not above thresholds. Set DATANG if
+ * data error occured on both second 59 and second 1. Finally,
+ * QSY back to the data channel.
+ */
case SYNC3: /* 1 */
cp = &up->mitig[up->achan];
+ if (up->sigamp < DTHR || up->datsnr < DSNR)
+ cp->errcnt++;
sp = &cp->wwv;
sp->synmin = (sp->synmin + sp->synamp) / 2;
sp->synsnr = wwv_snr(sp->synmax, sp->synmin);
- sp->select &= ~SYNCNG;
+ sp->select &= ~(DATANG | SYNCNG);
if (sp->synmax < QTHR || sp->synsnr < QSNR)
sp->select |= SYNCNG;
+ if (cp->errcnt > 1)
+ sp->select |= DATANG;
rp = &cp->wwvh;
rp->synmin = (rp->synmin + rp->synamp) / 2;
rp->synsnr = wwv_snr(rp->synmax, rp->synmin);
- rp->select &= ~SYNCNG;
+ rp->select &= ~(DATANG | SYNCNG);
if (rp->synmax < QTHR || rp->synsnr < QSNR)
rp->select |= SYNCNG;
+ if (cp->errcnt > 1)
+ rp->select |= DATANG;
- if (up->status & MSYNC) {
- sprintf(tbuf,
- "agc %d sync %3s %04x %d %.0f/%.1f/%ld %3s %04x %d %.0f/%.1f/%ld",
- up->gain, sp->ident, sp->select, sp->count,
- sp->synmax, sp->synsnr, sp->jitter,
- rp->ident, rp->select, rp->count,
- rp->synmax,rp->synsnr, rp->jitter);
- if (pp->sloppyclockflag & CLK_FLAG4)
- record_clock_stats(&peer->srcadr, tbuf);
+ cp->errcnt = 0;
+ sprintf(tbuf,
+ "wwv5 %d %s %04x %d %.0f/%.1f/%ld %s %04x %d %.0f/%.1f/%ld",
+ up->gain, sp->ident, sp->select, sp->count,
+ sp->synmax, sp->synsnr, sp->jitter, rp->ident,
+ rp->select, rp->count, rp->synmax,rp->synsnr,
+ rp->jitter);
+ if (pp->sloppyclockflag & CLK_FLAG4)
+ record_clock_stats(&peer->srcadr, tbuf);
#ifdef DEBUG
- if (debug)
- printf("wwv5 %s\n", tbuf);
+ if (debug)
+ printf("%s\n", tbuf);
#endif /* DEBUG */
- up->status &= ~SFLAG;
- wwv_newchan(peer);
- }
+ up->status &= ~SFLAG;
+ wwv_newchan(peer);
break;
/*
/*
* Miscellaneous bits. If above the positive threshold, declare
* 1; if below the negative threshold, declare 0; otherwise
- * raise the SYMERR alarm. At the end of minute 58, QSY to the
+ * raise the SYMERR alarm. At the end of second 58, QSY to the
* probe channel.
*/
case MSC20: /* 55 */
up->misc &= ~arg;
else
up->alarm |= 1 << SYMERR;
- if (up->status & MSYNC) {
- up->schan = (up->schan + 1) % NCHAN;
- wwv_qsy(peer, up->schan);
- up->status |= SFLAG;
- }
+ up->schan = (up->schan + 1) % NCHAN;
+ wwv_qsy(peer, up->schan);
+ up->status |= SFLAG;
break;
/*
- * The endgame. If all nine clock digits are valid and the
- * SYNERR alarm is not raised in the current or previous second,
- * the clock is set set or validated. If at least one digit is
- * set, which by design must be the minute units digit, the
- * clock state machine begins to count the minutes. If the
- * SECWARN bit is set on the last minute of 30 June or 31
- * December, the LEPSEC bit is set. At the end of the minute in
- * which LEPSEC is set the transmitter and receiver insert an
- * extra second (60) in the timescale and the minute sync skips
- * a second. We only get to test this wrinkle at intervals of
- * about 18 months, so your mileage may vary.
+ * The endgames
+ *
+ * Second 59 contains the first data pulse of the probe
+ * sequence. Check it for validity and establish the noise floor
+ * for the minute sync SNR.
*/
case MIN1: /* 59 */
cp = &up->mitig[up->achan];
+ if (up->sigamp < DTHR || up->datsnr < DSNR)
+ cp->errcnt++;
sp = &cp->wwv;
sp->synmin = sp->synamp;
sp = &cp->wwvh;
sp->synmin = sp->synamp;
+
+ /*
+ * If SECWARN is set on the last minute of 30 June or 31
+ * December, LEPSEC bit is set. At the end of the minute
+ * in which LEPSEC is set the transmitter and receiver
+ * insert an extra second (60) in the timescale and the
+ * minute sync skips a second. We only get to test this
+ * wrinkle at intervals of about 18 months, the actual
+ * mileage may vary.
+ */
if (up->tsec == 60) {
up->status &= ~LEPSEC;
break;
}
/* fall through */
+ /*
+ * If all nine clock digits are valid and the SYNERR alarm is
+ * not raised in the current or previous second, the clock is
+ * set or validated. If at least one digit is set, which by
+ * design must be the minute units digit, the clock state
+ * machine begins to count the minutes.
+ */
case MIN2: /* 59/60 */
up->minset = ((current_time - peer->update) + 30) / 60;
if (up->digcnt > 0)
if (up->minset > PANIC)
up->status = 0;
up->alarm = (up->alarm & ~0x8888) << 1;
- up->errcnt = up->digcnt = nsec = 0;
up->nepoch = (up->mphase + SYNSIZ) % MINUTE;
+ up->errcnt = up->digcnt = nsec = 0;
break;
}
+ if (!(up->status & DSYNC)) {
+ sprintf(tbuf,
+ "wwv3 %2d %04x %5.0f %5.0f %5.0f %5.1f %5.0f %5.0f",
+ up->rsec, up->status, up->epomax, up->sigamp,
+ up->datpha, up->datsnr, bit, bitvec[up->rsec]);
+ if (pp->sloppyclockflag & CLK_FLAG4)
+ record_clock_stats(&peer->srcadr, tbuf);
+#ifdef DEBUG
+ if (debug)
+ printf("%s\n", tbuf);
+#endif /* DEBUG */
+ }
up->rsec = up->tsec = nsec;
- return (rval);
+ return;
}
/*
* If the data amplitude or SNR are below threshold or if the
- * pulse length is less than 170 ms, declare an erasure. Don't
- * count the errors if not in minute sync or if in probeing
- * mode.
+ * pulse length is less than 170 ms, declare an erasure.
*/
- if (!(up->status & MSYNC) || up->status & SFLAG)
- return (0);
if (up->sigamp < DTHR || up->datsnr < DSNR || dpulse < DATSIZ) {
up->status |= DGATE;
up->errcnt++;
}
if (vp->digit != mldigit)
up->alarm |= 1 << DECERR;
- if (up->status & MSYNC && !(up->status & INSYNC)) {
+ if (!(up->status & INSYNC)) {
sprintf(tbuf,
"wwv4 %2d %04x %5.0f %2d %d %d %d %d %5.0f %5.1f",
up->rsec, up->status, up->epomax, vp->radix,
/*
* This is a little tricky. Due to the way things are measured,
- * either or both the signal or noise amplitude could negative
- * or equal to zero. The intent is that, if the signal is
- * negative or zero, the SNR must always be zero. This can
- * happen with the subcarrier SNR before the phase has been
- * aligned. On the other hand, in the likelihood function the
- * "noise" is the next maximum down from the peak and this could
- * be negative. However, in this case the SNR is truly
- * stupendous, so cap at MAXSNR dB.
+ * either or both the signal or noise amplitude can be negative
+ * or zero. The intent is that, if the signal is negative or
+ * zero, the SNR must always be zero. This can happen with the
+ * subcarrier SNR before the phase has been aligned. On the
+ * other hand, in the likelihood function the "noise" is the
+ * next maximum down from the peak and this could be negative.
+ * However, in this case the SNR is truly stupendous, so we
+ * simply cap at MAXSNR dB.
*/
if (signal <= 0) {
rval = 0;
* each of five frequencies. While the radio is tuned to the working
* data channel (frequency and station) for most of the minute, during
* seconds 59, 0 and 1 the radio is tuned to a probe channel, in order
- * to pick up minute sync pulses. The search for WWV and WWVH stations
- * operates simultaneously, with WWV on 1000 Hz and WWVH on 1200 Hz. The
- * probe channel rotates for each minute over the five frequencies
- * picking up the minute pulse peak and other data. At the end of each
- * rotation, this routine mitigates over all channels and chooses the
- * best frequency and station.
+ * to pick up minute sync and data pulses. The search for WWV and WWVH
+ * stations operates simultaneously, with WWV on 1000 Hz and WWVH on
+ * 1200 Hz. The probe channel rotates for each minute over the five
+ * frequencies. At the end of each rotation, this routine mitigates over
+ * all channels and chooses the best frequency and station.
*/
static void
wwv_newchan(
up = (struct wwvunit *)pp->unitptr;
/*
- * Reset the filter selector and station pointer to avoid
- * fooling around should we lose this game.
+ * Reset the matched filter selector and station pointer to
+ * avoid fooling around should we lose this game.
*/
up->sptr = 0;
up->status &= ~(SELV | SELH);
/*
* Search all five station pairs looking for the station with
- * the best metric, here defined by the compare counter.
+ * the maximum compare counter. Ties go to the highest frequency
+ * and then to WWV.
*/
j = 0;
sp = (struct sync *)0;
}
/*
- * If we find a station, continue to track it. If not, track the
- * one going now.
+ * If we find a station, continue to track it. If not, X marks
+ * the spot and we wait for better ions.
*/
if (rank > 0) {
up->dchan = j;
/*
* wwv_qsy - Tune ICOM receiver
*
- * This routine saves the current AGC for the current channel, switches
- * to a new channel and restores the AGC for that channel. If a tunable
- * receiver is not available, just fake it.
+ * This routine saves the AGC for the current channel, switches to a new
+ * channel and restores the AGC for that channel. If a tunable receiver
+ * is not available, just fake it.
*/
static void
wwv_qsy(
* dut DUT sign and magnitude in deciseconds
* lset minutes since last clock update
* agc audio gain (0-255)
- * stn station identifier (station and frequency)
+ * iden station identifier (station and frequency)
* comp minute sync compare counter
* errs bit errors in last minute\v * freq frequency offset (PPM)\v * avgt averaging time (s)\v */
static int
*/
synchar = (up->status & INSYNC) ? ' ' : '?';
qual = 0;
- if (up->alarm & (3 << (DECERR)))
+ if (up->alarm & (3 << DECERR))
qual |= 0x1;
- if (up->alarm & (3 << (SYMERR)))
+ if (up->alarm & (3 << SYMERR))
qual |= 0x2;
- if (up->alarm & (3 << (MODERR)))
+ if (up->alarm & (3 << MODERR))
qual |= 0x4;
- if (up->alarm & (3 << (SYNERR)))
+ if (up->alarm & (3 << SYNERR))
qual |= 0x8;
year = up->decvec[7].digit + up->decvec[7].digit * 10;
if (year < UTCYEAR)
projects / thirdparty / ntp.git / commitdiff
