How can you do an Hour along with other 5 categories when the GW60, GW52, GT31 do record data on the East Coast of Australia on occasions ? Only seem to be sailors from NSW and Qld.
This is happening randomly and at different locations.
I can not supply Garmin files until it happens to me or someone else as I have not kept them in the last 2 years.

On the track below Steve did not have a backup Garmin for you to look at but it is obvious the data is missing.

www.ka72.com/Track/t/410432

Interesting that KA will not show tracks on Map?

At 5 satellites in GPS results for the Hour 46.97 for 45.21 mins.
At 3 Satellites in GPS results for the Hour 47.10 for 50.21 mins.
Can not filter below 3 satellites in GPS results filter.

I personally also gave away my 2 Canmores as they were being phased out from 2020.

Can the Technical Committee please advice of your solution for posting to GPSTC as you will not allow Garmin file as backup and have no other back up device to show what we actually did on the session when this data when this arises.
Wearing 2 or 3 approved devices will not solve this issue.

Please do not bring up here Motion is a solution as we know the availability issues.

Please can all kept responses to the topic "Holes in GPS".

There are large gaps in the 0.2 recording and in the m/s Na appears instead of a numeric number.

Cocky2,
The two graphs below show the available satellites for 18-Dec in Newcastle and Perth. Unfortunately for those on the east coast the bad patch is mid afternoon, where as for WA it is very early in the morning, so no problem there.

When only 5 satellites are available it is always going to be a battle to get an accurate reading, when the antenna is small and sometimes on the wrong side of your body. As others have said you can give yourself the best chance by wearing the device on your shoulder or head. But there are no guarantees. The low satellite availability patch will gradually move away from midafternoon but this will take months.

Until then there is no solution for posting to TC (as we are not going to talk about the Motion). Of course if you want to record your "Hours" accurately during these periods you can use any modern Garmin which has Glonass. Most folk would also get away with posting Garmin numbers to TC, but not you as I suspect they check your posts!

Just done a Satellite check for Lake George mid February 2020
It looks good apart from a couple of low spots at breakfast time which only apply to Kato

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tbwonder said..
Cocky2,
The two graphs below show the available satellites for 18-Dec in Newcastle and Perth. Unfortunately for those on the east coast the bad patch is mid afternoon, where as for WA it is very early in the morning, so no problem there.

When only 5 satellites are available it is always going to be a battle to get an accurate reading, when the antenna is small and sometimes on the wrong side of your body. As others have said you can give yourself the best chance by wearing the device on your shoulder or head. But there are no guarantees. The low satellite availability patch will gradually move away from midafternoon but this will take months.

Until then there is no solution for posting to TC (as we are not going to talk about the Motion). Of course if you want to record your "Hours" accurately during these periods you can use any modern Garmin which has Glonass. Most folk would also get away with posting Garmin numbers to TC, but not you as I suspect they check your posts!

Andrew ,
Thanks For your opinion however
Awaiting solution from GPSTC committee.

What happens at LG has no relevance to this topic.

Probally why WA is happy with Current GPS data issues as not many sea breezes in the morning .

What do you expect them to do? Launch a few more satellites to fill in the gaps?
There is no 'AVAILABLE' device that records error data and uses the Glonass system.

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tbwonder said..
What do you expect them to do? Launch a few more satellites to fill in the gaps?
There is no 'AVAILABLE' device that records error data and uses the Glonass system.

Andrew,
please let GPSTC committee respond to the topic.

thanks

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Cocky2 said..

tbwonder said..
What do you expect them to do? Launch a few more satellites to fill in the gaps?
There is no 'AVAILABLE' device that records error data and uses the Glonass system.

Andrew,
please let GPSTC committee respond to the topic.

thanks

I don't really understand, are you suggesting that the GPSTC committee will be somehow silenced by my comments. Well I am quite flattered!

Well I'm not speaking for the advisory panel here, but my personal opinion is well reflected by Andrew's comments.
It's a great shame and big worry, but if the sats aren't there, and you don't have an approved multi GNNS device well I guess you miss out.

There are alternatives to the motion.
Peter your brother said in another thread.

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So what you are a sparky, I have been a sparky for 35 years and done electronic study at Tafe for 2 years.

He should be able to make a ublox logger or two, we'll just need a few files from it and a GW52 both worn close together on head or upper arm, to make sure it's working properly. And it can be approved.

Here's the basic idea, but there are several alternatives, I'm more than happy to help





Here's another one. This is more complicated as it still has the serial to USB converter so I can configure the GPS. Once that's been done, all that's needed is the BBN880, battery, on/off switch and the logomatic. All those change over switches and converter can be done away with. Doesn't get much easier than than that.

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decrepit said..
Well I'm not speaking for the advisory panel here, but my personal opinion is well reflected by Andrew's comments.
It's a great shame and big worry, but if the sats aren't there, and you don't have an approved multi GNNS device well I guess you miss out.

There are alternatives to the motion.
Peter your brother said in another thread.

So what you are a sparky, I have been a sparky for 35 years and done electronic study at Tafe for 2 years.

He should be able to make a ublox logger or two, we'll just need a few files from it and a GW52 both worn close together on head or upper arm, to make sure it's working properly. And it can be approved.

Here's the basic idea, but there are several alternatives, I'm more than happy to help

Mike,
So what you are saying if it does not affect you in WA you do not care about GPSTC being a fair competition.

Maybe if WA team that drives 4 hrs to Albany to then find when they upload their Numbers are not as good as data missing we may see more interest?

Really disappointing to read your thoughts.

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Cocky2 said..
Mike,
So what you are saying if it does not affect you in WA you do not care about GPSTC being a fair competition.

Maybe if WA team that drives 4 hrs to Albany to then find when they upload their Numbers are not as good as data missing we may see more interest?

Really disappointing to read your thoughts.

Wow Pete, that is some inference.
Yes you are probably right, if we started missing out on sats here, I'd knock up a few more loggers, for my team.
For your info, 99% of the advisory panel are on the East Coast.
I'm just stating facts, we can't magically manufacture a solution to this problem.

As Sailquick has pointed out, the Canmore doesn't report any sat info, so that sat numbers aren't filtered for, that's the only reason it gives a result, which is highly compromised.

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decrepit said..

Cocky2 said..
Mike,
So what you are saying if it does not affect you in WA you do not care about GPSTC being a fair competition.

Maybe if WA team that drives 4 hrs to Albany to then find when they upload their Numbers are not as good as data missing we may see more interest?

Really disappointing to read your thoughts.

Wow Pete, that is some inference.
Yes you are probably right, if we started missing out on sats here, I'd knock up a few more loggers, for my team.
For your info, 99% of the advisory panel are on the East Coast.
I'm just stating facts, we can't magically manufacture a solution to this problem.

As Sailquick has pointed out, the Canmore doesn't report any sat info, so that sat numbers aren't filtered for, that's the only reason it gives a result, which is highly compromised.

Mike it is Ian .
My understanding is that the technical advisory committee has no members in NSW or Qld where the data is failing?

Sorry Ian, getting old and stupid, I always seem to mix you two up.

No you have members in both places, 2 in Queensland I think and at least one in NSW

OK Ian, here is a response from the GPSTC team, among whom this has been discussed at length.

Apart from making yourself aware of when the danger period at your location are likely to be, and trying to work with that....

We have a number of reports that the GT-31's are either not affected by the low satellite periods, or are very much less affected. Again, it will depend on the way in which they are worn for best reception and that is in the control of the individual sailor.

We also have reports that GW-52 (and even the GW-60) worn on the upper arm or helmet have less issues with low sat availability than the GW-60's worn on the wrist. Again, this aspect is within the control of the sailor. If anyone else has personal experience either way we would like to hear from them directly by email: info@gpsteamchallenge.com.au

For users of the GW-52 and GW-60, be aware that the device is designed to stop recording Doppler data when the satellite fix gets below 5. This is actually a very good design attribute and one of the very good reasons why this device is approved for competition. Extensive testng during the development of the GW series showed that there is a significant drop in accuracy below 5 satellites.

But positional information continues to be recorded (again with lower accuracy) as long as the GPS has a fix (usually requires 4 satellites). This means that there is a possibility to get reasonably accurate distance data. It may also be acceptable for something like the 1 hr but it would obviously have to be looked at on a case by case basis.

So if anyone finds themselves in a position where they have gaps in their Doppler data, they are advised to contact the GPSTC Admin team to discuss what they may be able to post. This very much a situation where it is essential to ask permission first, rather than beg forgiveness after, as the latter will not be granted.