Andy,
I should point out that the High and Low latitude simulations are about the
worse one can expect in terms of signal distortion. The timing delays and
signal spread are what you might see during a magnetic / ionospheric storm. As
you know, the polar paths are usually the worse.
There are so many variations between the quite ionosphere and severely
disturbed that testing lots of different combinations with the simulator would
be very time consuming. I went the 'severe' route to save time and show what
modes would be useful under the worse conditions.
The mid-latitude disturbance is much less severe than polar paths and the
simulator shows how the majority of digital modes survive with lower signal
spread and shorter path delays. Some modes start showing decode problems with
only a slight (agitation) of the refracting layer and it's interesting to
watch.
I'm going to add a few modes for NVIS and hopefully shed some light on what
works. Multi-path timing delays between the direct path and sky wave are said
to be as high as 20ms with NVIS. My guess is that some modes will not print at
all with timing issue of that magnitude.
Tony, K2MO
___
Ionospheric Path Simulations for Amateur Radio Digital Modes
All SNR figures measured through 3KHz band pass filter.
Sensitivity Test - Direct Path
(no ionospheric disturbance)
Minimum SNR for 100% decode
Jason Turbo (Fast)..-25db
Contestia 500/32-15db
DominoEX-4 ..-15db
FEC-31...-15db
THROBX-4..-15db
MFSK16...-14db
THOR11...-14db
RTTYM**...-13db
Contestia 500/16-13db
CW 20 WPM...-13db***
THOR16...-12db
Olivia 500/16 . -12db
MFSK31*-12db
Olivia 500/8.-10db
PSK31 -10db
DominoEX-11...-8db
MT63 1K-8db
Olivia 500/4.. -8db
PSK63..-7db
Feld Hell-7db
RTTY 45-5db
* MFSK 31.25 baud. MMVARI Software.
** Intermittent decode problem with RTTYM regardless of SNR
*** Subjective - speed dictates SNR
__
Sensitivity Test - Direct Path -12db SNR
(no ionospheric disturbance)
Percentage of decode for modes with SNR threshold above -12db
Olivia 500/8 ...90%
Olivia 500/490%
DominoEX 1190%
PSK3190%
PSK6320%
Feld Hellreadable
MT63 1K...no copy
RTTY 45 baud..no copy
___
Sensitivity Test - Direct Path
(no ionospheric disturbance)
Percentage of decode for modes with SNR threshold above -15db
MFSK16...95%
Contestia 500/32.95%
Olivia 500/16...90%
Thor11..80%
RTTYM..80%
Contestia 500/16...50%
DominoEX 11bd50%
Olivia 500/8.. 50%
MFSK3150%
PSK3150%
Feld Hell..No Copy
MT63...No Copy
Olivia 500/4No Copy
PSK63No Copy
RTTY 45..No Copy
THOR16..No Copy
___
High-Latitude Moderate Disturbance - 3ms path delay - frequency spread 10Hz -
SNR -8db)
Contestia 500/16100%
CW 20 WPM...100%
MFSK16..100%
MFSK31**...100%
Olivia 500/16...100%
Olivia 500/8..100%
RTTYM 500/32.100%
Olivia 500/490%
Feld Hell. ...90%*
ThrobX-470%
DominoEX 4bd..No Copy
DominoEX 11bdNo Copy
FEC-31No Copy
PSK31.No Copy
Jason Turbo (fast)No Copy
PSK63.No Copy
RTTY45No Copy
THOR-11.No Copy
THOR-16.No Copy
MT63No Copy
*diffuse print - readable
** MFSK 31.25 baud MMVARI Software.
___
High-Latitude Disturbed - 7ms path delay - frequency spread 30Hz - SNR -3db )
Contestia 500/16...100%
CW 20 WPM..100%
Olivia 500/16..100%
Olivia 500/8.100%
Olivia 500/4..95%
RTTYM..95%**
MFSK31.. 90%
MFSK16...75%