Transmitted waveforms
Transmission and
recording
summary timeline: Excel HTML
Transmission bands:
- Low (8-16 kHz)
- Mid (14-22 kHz)
- High (25-50 kHz)
Deployments 1 and 2
- Probes schedule (aka
Schedule
1): Excel HTML (how 1 minute chirp
intervals in low, mid and high bands are interleaved)
- Transmitted
files (16-bit
time series, sampled at 192000 Hertz - chirps only for Schedule 1)
- LFM chirp parameters
(for each band)
- Low and mid bands:
- 50 milliseconds
duration
- linear sweep from
lower edge of band to upper edge of band (8000 to 16000 in low band;
14000
to 22000 in mid band)
- repeated every
250
milliseconds (i.e. there is a 200 millisecond gap between individual
chirps)
- High band:
- 25 milliseconds
duration
- linear sweep from
lower edge of band to upper edge of band (25000 to 50000 in low band)
- repeated every
200
milliseconds (i.e. there is a 175 millisecond gap between chirps)
- M-file to generate
these probe pulses (to be posted)
- Communications schedule
(aka Schedule 2): Excel
HTML
(how
5 minute intervals from each of the multiple transmitters operating in
low,
mid and high bands are interleaved)
- Transmitted
files (16-bit time series, sampled at 192000 Hertz)
- Lineup of
waveforms:
Excel HTML (sequence of waveforms
within
each 5 minute interval)
- LFM probes
- PSK and OFDM
(SAIC/SSC)
- PSK (APL-UW)
- M-sequence probes
- bi-polar sequence
used (to be posted)
- 4000 chips/second
- carrier frequency
is the middle of the band (12000 Hz in low band, 18000 Hz in mid band)
- M-file to
generate
these probe pulses (to be posted)
- Direct sequence
spread
spectrum (SAIC)
- PSK (APL-UW)
- MFSK (SAIC)
Deployment 3
- Probes: (for
schedule,
see: Excel HTML)
- LFM (as in
deployments
1 and 2)
- LFM (durations of
100,
150, and 200 milliseconds, pulse repetition interval of 250
milliseconds)
- Multi-user access
communications:
(for schedule of 5 minute intervals, see: Excel HTML)
(for
lineup of waveforms within each 5 minute interval, see: Excel HTML)
- Direct sequence
spread
spectrum
- Frequency hopped
frequency
shift keying (WHOI Interoperability standard)
- Frequency hopping
patterns
occupy roughly 4kHz in bandwidth
- Hopping patterns
were
tested in the lower and upper halves of our low and mid bands (four
4kHz
bands: 8-12, 12-16, 14-18, 18-22 kHz)
- Two rates were
tested
in each 4kHz band: 80 bps and 160 bps (these rates are uncoded; a 1/2
rate
convolutional code and header overhead reduce these to roughly half)