Select to expand quote

jamesf said..
My team-mate is having similar issues with the Pixie. Lots of spikes (see below). His Samsung Galaxy S3, and my Experia E1 give perfect data.

Would love to hear if anyone has any hints on getting the Pixie to give clear data.

James, my Pixie gives good data as long as the display is ON, it's only when the display accidentally turns off that it all turns to that smelly organic stuff.
Well if it doesn't have a good sky view the data isn't brilliant but it's no where near as bad as what happens when the display turns off.
I suspect the S3 doesn't have this problem.

Actually I get better results with the pixie than the xperia, and the best results for both is with it on my head.
Don't bump the sail with it though because that can also turn the display off.

Select to expand quote

decrepit said..

mathew said..
Phones use a "chip antenna" that is much smaller than the patch antenna used within the GT31 - this greatly affects the reception capability of the device. With this knowledge, there is no reason at all to think a phone would have anywhere near the same accuracy. Can you clarify how you came to this conclusion ?

Mathew, a bit of wild speculation here, is it possible to have a better antenna, say on the top of your helmet, inductively coupled to the phone antenna? Would mean running a bit of wire around the body, I guess coax that would have to be well sealed?

Guys don't throw those old GTs away, there may be a use for their antennas.

Short answer is no - a passive coupling would result in too much signal loss.

Normally antenna cabling needs to be taken into account in any type of antenna design (radio, wifi, GPS, etc). Chip antennas work in phones because they are located within a few cm of the electronics - they move the cabling losses problem, to a small-antenna losses problem.

It goes without saying that a chip antenna needs to packaged in the device in such a way, as to help offset any further losses. For example, in a phone the antenna is usually place a the "top".

Also for a passive coupling, any gain achieved with the bigger antenna, then needs to pass-through another rather-poor coupling.


.... an active (powered) coupling would be suitable. But then making the unit water tight is another matter.

Thanks Mathew, I reflected a bit after posting and suspected that would be the case.

My GPS got flooded and is Fuctus! and looking at getting the Garmin watch GPS - which Garmin watch is suitable/should I be looking at???

The trouble with watches, you tend to wear them on your wrist. This can produce some funny results during gybes. Apart from that I can't help you, except I have a feeling there aren't any approved watches, but I could be wrong.

Select to expand quote

Roo said..
Well this will put the cat amongst the pigeons, but what gps units are acceptable for the Team Challenge. If the unit is allowed on GPS3S then by default it is allowed on the GPSTC? If you can post your speeds there and linked to here then that's OK?

As the GT31 is now at its end of life and no longer available what alternatives are available in each country. In the USA the only way to get into posting is to buy a phone and GPSLogit app, no GW52 are available.

Remember the GPSTC is all about participation and getting people involved, no sheep-stations at stake! Do we want more people involved, I reckon yes. If that is the case do we accept the new tech like phone apps but just put in brackets afterwards (GPSLogit) like we do for (Doppler) or (Trackpoint).

so is there a list of approved units?

When uploading tracks to the gps speedsurfing site you can choose from the following ones. At least the Garmin Forerunner 920XT got approved this year and is in that list. The Fenix3, Forerunner 230, 235 and 630 might work too, but have not been tested yet. But I assume they are as good or better as the other listed Forerunners.

Select to expand quote

Hooksey said..

so is there a list of approved units?

If you go to "Rules" on the site you'll come across this.

Select to expand quote

The following GPS's are considered valid for the purposes of the challenge (most preferable at the top, least preferable at the bottom):

NAVI GT-35 (uses 0.2 sec recording intervals which is approved for this Challenge)
NAVI GT-31 (uses 1 sec recording intervals)
NAVI GT-11 (uses 1 sec recording intervals)
Garmin Foretrex Series
Garmin Gecko Series
Garmin Edge (1 second setting)
Garmin Legend Cx (1 second setting),

It's a bit out of date, the Canmore or GW52 isn't on it yet, but both are approved.

I see the Garmin Forerunner 10 15 25 watches look great and what I am after but do they suit the GPS team challenge rules? Will need Technical advisors approval as below from the GPS team Challenge site

Special Note:

Technical Advisers for the challenge will be as follows: Roo (NAVi GPS) Sailquik (General) and Slowboat (General). The following GPS's are considered valid for the purposes of the challenge (most preferable at the top, least preferable at the bottom): NAVI GT-35 (uses 0.2 sec recording intervals which is approved for this Challenge) NAVI GT-31 (uses 1 sec recording intervals) NAVI GT-11 (uses 1 sec recording intervals) Garmin Foretrex Series Garmin Gecko Series Garmin Edge (1 second setting) Garmin Legend Cx (1 second setting), Other GPS units can be approved by the technical advisers of the challenge. All software should be set to "Doppler if available" for all categories

Technical advisers/GPSTC organisers - please make a judgment one way or the other on the GPSLogit app. Even if you have to specify certain phones are OK / not OK.

At the moment any time somebody records a decent session with the phone, they are told their speeds are doubtful. Peoples PBs are being called into question, which is unfair. We need a decision to be made.

Thanks,
James

We have been testing and considering approval of the GPS-Logit app for quite a while. A few weeks ago we we almost sure we could approve it within some limitations. Unfortunately, the more testing we do, the worse the situation looks.

At this stage it is Not Approved for use on GPS-TC posting.

There are just too many problems we have encountered.

We were considering trying to approve certain phone models but the more we look into it, the worse that idea looks as well.

My opinion is that it is now unlikely that GPS-Logit will be approved for posting on GPS-TC anytime soon.

Note: the Logit app is still a very useful tool for getting instant feedback of speeds and results while sailing and is recommended for that use. Just don't always rely on the info it gives you.

Select to expand quote

AusMoz said..

I see the Garmin Forerunner 10 15 25 watches look great and what I am after but do they suit the GPS team challenge rules? Will need Technical advisors approval as below from the GPS team Challenge site

Special Note:

Technical Advisers for the challenge will be as follows: Roo (NAVi GPS) Sailquik (General) and Slowboat (General). The following GPS's are considered valid for the purposes of the challenge (most preferable at the top, least preferable at the bottom): NAVI GT-35 (uses 0.2 sec recording intervals which is approved for this Challenge) NAVI GT-31 (uses 1 sec recording intervals) NAVI GT-11 (uses 1 sec recording intervals) Garmin Foretrex Series Garmin Gecko Series Garmin Edge (1 second setting) Garmin Legend Cx (1 second setting), Other GPS units can be approved by the technical advisers of the challenge. All software should be set to "Doppler if available" for all categories

Current approved GPS devices also include the Canmore G-Porter 102 and the GW-52.

The GT-31 or GW-52 should be used by anyone in the top rankings or posting for team scores. The Canmore is acceptable provided the tracks are scrutinised carefully for errors. If there is any doubt, team captains should have them checked by someone qualified to do so.

None of the other GPS should be used by those in the top 50 rankings, or for posting score that count for the team rankings competition as they either do not produce Doppler derived speed data, or the data and speeds are not able to be verified to an acceptable level.

GPS-Logit is not currently approved for posting on GPS-TC

Select to expand quote

sailquik said..

...
At this stage it is Not Approved for use on GPS-TC posting.
....

Thanks Andrew. I will pass on to my team.

Select to expand quote

jamesf said..
Technical advisers/GPSTC organisers - please make a judgment one way or the other on the GPSLogit app. Even if you have to specify certain phones are OK / not OK.

At the moment any time somebody records a decent session with the phone, they are told their speeds are doubtful. Peoples PBs are being called into question, which is unfair. We need a decision to be made.

Thanks,
James

Byron's track is perfectly valid and he did a 27.184 alpha. I just ran the track through GPSResults and adjusted the filters to make sure. It's got no spikes and is clean. I set the acceleration filter to 2.0 m/s, default is 5.0m/s, and compared trackpoint and doppler to check for anomalies. In trackpoint is gives 27.214 and doppler gives 27.184. Roo

Select to expand quote

sailquik said..

AusMoz said..

I see the Garmin Forerunner 10 15 25 watches look great and what I am after but do they suit the GPS team challenge rules? Will need Technical advisors approval as below from the GPS team Challenge site

Special Note:

Technical Advisers for the challenge will be as follows: Roo (NAVi GPS) Sailquik (General) and Slowboat (General). The following GPS's are considered valid for the purposes of the challenge (most preferable at the top, least preferable at the bottom): NAVI GT-35 (uses 0.2 sec recording intervals which is approved for this Challenge) NAVI GT-31 (uses 1 sec recording intervals) NAVI GT-11 (uses 1 sec recording intervals) Garmin Foretrex Series Garmin Gecko Series Garmin Edge (1 second setting) Garmin Legend Cx (1 second setting), Other GPS units can be approved by the technical advisers of the challenge. All software should be set to "Doppler if available" for all categories

Current approved GPS devices also include the Canmore G-Porter 102 and the GW-52.

The GT-31 or GW-52 should be used by anyone in the top rankings or posting for team scores. The Canmore is acceptable provided the tracks are scrutinised carefully for errors. If there is any doubt, team captains should have them checked by someone qualified to do so.

None of the other GPS should be used by those in the top 50 rankings, or for posting score that count for the team rankings competition as they either do not produce Doppler derived speed data, or the data and speeds are not able to be verified to an acceptable level.

GPS-Logit is not currently approved for posting on GPS-TC

Thanks Sailquik!

Just ordered my Canmore!

I don't think the top 50 have to worry about me! - its more for the team and to challenge myself!

AusMoz

Select to expand quote

Roo said..
>>>>
Byron's track is perfectly valid and he did a 27.184 alpha. I just ran the track through GPSResults and adjusted the filters to make sure. It's got no spikes and is clean. I set the acceleration filter to 2.0 m/s, default is 5.0m/s, and compared trackpoint and doppler to check for anomalies. In trackpoint is gives 27.214 and doppler gives 27.184. Roo

Well that really is a bugger!!!!!
Big commiserations Byron, sorry if any confusion we've caused has led to a big disappointment.

GPSLogit is currently approved for use on GPS Speedsailing. From what I understand you can post your results from there to the GPSTC. Does it make sense to have 2 sets of rules, especially when the sites are connected? It's a bit like having one sheep station for black sheep (I'm sure I'm on that one) and one for white sheep.

Roo

AusMoz Just used a Canmore yesterday next to my Navi. Could barely tell the difference on Google earth. In fact at speed the tracks overlapped (barely cm diff). It was only at walking speed that I could I tell that both tracks were loaded. On GPSAR the average of the top 5 2second and top 5 10second bests was only 1/100 knot different. The worst individual speed diff was 0.04 knot.. I had both receivers beside each other in the aquapack.

Only problem is small screen and km/hr display(and technically lack of sat data). Canmore have the same chip and software in the gp-101 which has a 2.25X bigger screen , replaceable phone type battery (used to come with spare as well, not sure if still does since last year update when they changed from Skytrak gps chip with NMEA output to Sirf chip with FIT file output same as GPorter) but worse waterproofing but that should not matter in aquapak.

Select to expand quote

yoyo said..
AusMoz Just used a Canmore yesterday next to my Navi. Could barely tell the difference on Google earth. In fact at speed the tracks overlapped (barely cm diff). It was only at walking speed that I could I tell that both tracks were loaded. On GPSAR the average of the top 5 2second and top 5 10second bests was only 1/100 knot different. The worst individual speed diff was 0.04 knot.. I had both receivers beside each other in the aquapack.

Only problem is small screen and km/hr display(and technically lack of sat data). Canmore have the same chip and software in the gp-101 which has a 2.25X bigger screen , replaceable phone type battery (used to come with spare as well, not sure if still does since last year update when they changed from Skytrak gps chip with NMEA output to Sirf chip with FIT file output same as GPorter) but worse waterproofing but that should not matter in aquapak.

Yes. The Canmores have shown themselves to be consistent and reliable and they are a known factor. There is no variable hardware and not much the can go wrong in the user interface. They are also cheap, so I recon they are a very good alternative, along with the GW-52, until the next generation of 10+hz Ublox based GPS come along at a reasonable price.

Select to expand quote

sailquik said..

yoyo said..
AusMoz Just used a Canmore yesterday next to my Navi. Could barely tell the difference on Google earth. In fact at speed the tracks overlapped (barely cm diff). It was only at walking speed that I could I tell that both tracks were loaded. On GPSAR the average of the top 5 2second and top 5 10second bests was only 1/100 knot different. The worst individual speed diff was 0.04 knot.. I had both receivers beside each other in the aquapack.

Only problem is small screen and km/hr display(and technically lack of sat data). Canmore have the same chip and software in the gp-101 which has a 2.25X bigger screen , replaceable phone type battery (used to come with spare as well, not sure if still does since last year update when they changed from Skytrak gps chip with NMEA output to Sirf chip with FIT file output same as GPorter) but worse waterproofing but that should not matter in aquapak.

Yes. The Canmores have shown themselves to be consistent and reliable and they are a known factor. There is no variable hardware and not much the can go wrong in the user interface. They are also cheap, so I recon they are a very good alternative, along with the GW-52, until the next generation of 10+hz Ublox based GPS come along at a reasonable price.

Will be buying a Garmin Watch as well and will compare them. Not sure which watch yet still looking through them all.

It was all much simpler when we all just had GTs and was a much more even playing field.
I still think the old GTs were best pitty we can't all just use the same device.
My old Gt-31 is dying but so am forced to use something else.

Wow didn't mean to cause so much trouble.
My GT31 didn't go flat it died so only one left.
It is disappointing that you have a validated alpha and yet you are saying its not allowed. People are posting all the time and you don't know what they are using.
I bought a phone because that's what every one was doing from the posts and it works. my problem I need to put plastic on the front of the phone to stop it being operated accidently.
so my options are get a canmore which is cheap and works but is in km/h and you cannot read the screen and yes most importantly I would be in the same vote when I do a good score again, as it will be scrutinised.
Buy a GW-52 costs $300 and is not currently working correctly with alphas Dylan has been working hard changing things to make it work????? so how is this any different or accurate for alphas.
so now not sure what to do no obvious options.

regarding GT11/31's

If batteries are the issue then specialized battery shops have them or can get them in.

From GPSSS


www.gps-speedsurfing.com/default.aspx?mnu=item&item=App

GPSLogit

For speedfreaks that already own a Android phone a good alternative could be the App GPS Logit, https://play.google.com/store/apps/details?id=com.mfuchs.gpslogit , this App is available at Google Play Store and developed by Manfred Fuchs, and is a good alternative for first-time and fun-speedsurfers. The App produces doppler speeds, at the same quality level of the old GT-11 .

The App records Dopplerspeeds from the GPS-chipsets that are implemented in all recent smartphones, so the accuracy is comparable to a GT11, the only missing item is the Dopplerspeed-error (SDOP) that only the GT31/GW52 or ublox-based units (Thingee) support.

So for record purposes it is not suited, however, for fun rankings it is way better than e.g. positional data from standard units. The SBP-file could be posted directly from the smartphone to GP3S or processed by GPSResults.

Select to expand quote

byronmc said..

so my options are get a canmore which is cheap and works but is in km/h and you cannot read the screen

I thought I recalled GPSSS had fully moved to km/h and while checking (they haven't) I noticed an advertisement for iFin boasting about an open water max speed.
<div>
"
Incredible V-Max for Ben Van Der Steen in open sea in Tarifa : 44.79 knots with the iFins Nano 34 ... "
www.gps-speedsurfing.com/default.aspx?mnu=user&val=170


Impressive speed although it looks a little bit smooth.

Had me wondering if any progress has been made defining open water for speed sailing purposes? How about a fetch of at least ~ 2 NM over deep water.

Select to expand quote

elmo said..
From GPSSS


www.gps-speedsurfing.com/default.aspx?mnu=item&item=App

GPSLogit

For speedfreaks that already own a Android phone a good alternative could be the App GPS Logit, https://play.google.com/store/apps/details?id=com.mfuchs.gpslogit , this App is available at Google Play Store and developed by Manfred Fuchs, and is a good alternative for first-time and fun-speedsurfers. The App produces doppler speeds, at the same quality level of the old GT-11 .

The App records Dopplerspeeds from the GPS-chipsets that are implemented in all recent smartphones, so the accuracy is comparable to a GT11, the only missing item is the Dopplerspeed-error (SDOP) that only the GT31/GW52 or ublox-based units (Thingee) support.

So for record purposes it is not suited, however, for fun rankings it is way better than e.g. positional data from standard units. The SBP-file could be posted directly from the smartphone to GP3S or processed by GPSResults.

This is effectively the same stance taken by GPS - TC as advised by Sailquick, i.e. Roo, we don't have 2 sets of rules to contend with between GPS - TC and GP3S.

Select to expand quote

Ian K said..

I noticed an advertisement for iFin boasting about an open water max speed.
<div>
"
Incredible V-Max for Ben Van Der Steen in open sea in Tarifa : 44.79 knots with the iFins Nano 34 ... "
www.gps-speedsurfing.com/default.aspx?mnu=user&val=170


Impressive speed although it looks a little bit smooth.

Had me wondering if any progress has been made defining open water for speed sailing purposes? How about a fetch of at least ~ 2 NM over deep water.

The description 'Open Water' for speedsailing is a joke! Everyone thinks of it as something different, and every definition you look up is different as well, but they all talk about water that is well away from any land barrier. 99% of the speedsailing that people claim is 'open water' is beside some sort of land barrier or other structure that keeps the water relatively smooth.

There will never bee ant record definition for 'Open Water' because it is nonsensical.

At WGPSSRC, we are working on differentiating between artificial and man made courses and 'natural speed courses'. Ie: The French and African canals are artificial, as would West Kirby marine lake be etc. Natural speed courses would be places like Southend UK, The Brace, Netherlans, Tarifa, Sandy Point, Lake George, etc.

The latest 10 second speed WGPSSRC ratified in a natural speed course is by Han Kreisel at 50.04 knots at The Brace, Netherlands.

GPS-SS is not a competition in the same way as GPS-TC. They put more emphasis on 'fun rankings'.

The GPS-Logit app is a wonderful bit of software and if everything goes perfectly well we have found that it 'sometimes'' give comparable results to GT-31 and GW-52. But we have seen enough wonky results in all the testing to be very wary of allowing it for the TC. The issues are almost all to do with the great variety of Phone and hardware, not to mention all the various software the phone run to conserve power etc. If some phones switch off during a session, when they come to life again they have shown some really bad results. Screens switching of and on can do this. There are other problems as well.

I short while back we thought we could test some popular models and makes some recommendations, but the great variety and regular changing models seems to make this a fruitless exercise.

For fun and information, the app is fantastic. So far we have found in use that the phones are just not reliable enough for a competition..

Select to expand quote

sailquik said..

Ian K said..

I noticed an advertisement for iFin boasting about an open water max speed.
<div>
"
Incredible V-Max for Ben Van Der Steen in open sea in Tarifa : 44.79 knots with the iFins Nano 34 ... "
www.gps-speedsurfing.com/default.aspx?mnu=user&val=170


Impressive speed although it looks a little bit smooth.

Had me wondering if any progress has been made defining open water for speed sailing purposes? How about a fetch of at least ~ 2 NM over deep water.

The description 'Open Water' for speedsailing is a joke! Everyone thinks of it as something different, and every definition you look up is different as well, but they all talk about water that is well away from any land barrier. 99% of the speedsailing that people claim is 'open water' is beside some sort of land barrier or other structure that keeps the water relatively smooth.

There will never bee ant record definition for 'Open Water' because it is nonsensical.

At WGPSSRC, we are working on differentiating between artificial and man made courses and 'natural speed courses'. Ie: The French and African canals are artificial, as would West Kirby marine lake be etc. Natural speed courses would be places like Southend UK, The Brace, Netherlans, Tarifa, Sandy Point, Lake George, etc.

The latest 10 second speed WGPSSRC ratified in a natural speed course is by Han Kreisel at 50.04 knots at The Brace, Netherlands.

Yes it's a joke at present because there is no definition. But I don't think we should say there will never be an "Open water" because it's nonsensical. There are many variations on "flat water" which could also be interpreted as a non-sensical, non-level playing field.

I agree natural and artificial is a sensible differentiation. The aim of an open water definition would be to come up with an easily specifiable minimum level of roughness that is close to as rough as it gets (from a speed sailing perspective).


Bretschneider nomogram (Bretschneider, 1970)


If a 2 NM fetch was chosen we can see from the Bretchneider nomogram the waves will be 2 feet with a period of about 2 1/2 seconds at 22 knots. It doesn't get much rougher than that for a speed sailor. Waves get higher but the period drops going to the top rh corner of the Nomogram. Swings and roundabouts, the playing field is levelling out. Well at least as level as it is for the flat water venues?

But look at the advantages!

Deep water fetches of 2NM are everywhere. All our coastal seabreezes come in over such a fetch. Botany Bay, Port Phillip Bay have sufficient fetch. ( Even Lake Illawarra if you head out west beyond the sandbar.)

Many sailors might also find that the optimum wind for pbs in open water is between 20 and 25 knots. You could be in the pb zone 2 to 3 times a week rather than once a year.

Select to expand quote

Ian K said..

If a 2 NM fetch was chosen we can see from the Bretchneider nomogram the waves will be 2 feet with a period of about 2 1/2 seconds at 22 knots. It doesn't get much rougher than that for a speed sailor. Waves get higher but the period drops going to the top rh corner of the Nomogram. Swings and roundabouts, the playing field is levelling out. Well at least as level as it is for the flat water venues?

But look at the advantages!

Deep water fetches of 2NM are everywhere. All our coastal seabreezes come in over such a fetch. Botany Bay, Port Phillip Bay have sufficient fetch. ( Even Lake Illawarra if you head out west beyond the sandbar.)

2 NM fetch wont work - Lake George probably comes close to a 2NM fetch, yet the chop can be less than 6 inches.

.... water depth matters more.