So many questions.

[V8Ian]

Last year during a Birdsville and Corner Country trip I simultaneously used a Navman My Escape and an entry model Tom Tom, they couldn't agree with each other and neither could agree with the Hema paper map (1:1,100,000?).
This year I will be driving from Boulia to Alice, I have purchased a Hema's Great Desert Tracks Simpson Desert sheet (1:1,100,000). I am considering purchasing this map in digital form.

Q 1. I have a Samsung Galaxy 7" tablet and a Sony Experia Z1 phone, both with a GPS on/off option. Is this a proper GPS or does it rely on the mobile network?

Q 2. Is the Hema digital map able to be downloaded to the above devices and/or the two GPS devices and used as a moving map?

Q 3. All of the above devices have Bluetooth, so if the map is loaded to one device, can it be viewed on the other devices per Bluetooth?

Q 4. If I download the file to my netbook, is it accessable, via Bluetooth, by the Navman/Tom Tom.

TIA, Ian.

[Saitch]

Ian
My brother has downloaded the Hema gear on to his Ipad but he's in NZ at the moment so I can't help you there. If the tablet is using the same GPS as some Iphones such as Android, then the accuracy will be around the 100m to 150m mark, maybe worse in hilly &/or thick canopy areas. I'm currently doing a job west of Warwick (Brrr Coldsville) & have ascertained the above accuracy using Google maps on my phone & knowing precisely were I am in relation to the cadastral boundaries i.e. +/- 100mm
Steve

[FeatherWeightDriver]

Tablet / phone accuracy on gps in perfect conditions should be around the 10-15m mark

[Saitch]

Tablet / phone accuracy on gps in perfect conditions should be around the 10-15m mark
They'd have to be perfect conditions then as I was using my Android & the property owner was using his phone, which I have no idea what it was but was pretty flash, & they were both about 100m + out in location in a 600 acre open paddock & as mentioned, I had the benefit of knowing exactly where I was in relation to the Cadastre.
Steve

[Tombie]

What datum was each unit using?

[Saitch]

Good question but you'd think they were using GDA94.......YES but would they & how do you find out?

[Tombie]

WGS84 is what they should be on :)

Somewhere in the GPS setting (I'm unfamiliar with those units) should be the option to select the Ellipsoid model..

[Tombie]

That is of course if you're not using UTM

[V8Ian]

Can you answer any of my questions Tombie? Seems you have knowledge of the subject.

[slug_burner]

Last year during a Birdsville and Corner Country trip I simultaneously used a Navman My Escape and an entry model Tom Tom, they couldn't agree with each other and neither could agree with the Hema paper map (1:1,100,000?).
This year I will be driving from Boulia to Alice, I have purchased a Hema's Great Desert Tracks Simpson Desert sheet (1:1,100,000). I am considering purchasing this map in digital form.

Q 1. I have a Samsung Galaxy 7" tablet and a Sony Experia Z1 phone, both with a GPS on/off option. Is this a proper GPS or does it rely on the mobile network?

Q 2. Is the Hema digital map able to be downloaded to the above devices and/or the two GPS devices and used as a moving map?

Q 3. All of the above devices have Bluetooth, so if the map is loaded to one device, can it be viewed on the other devices per Bluetooth?

Q 4. If I download the file to my netbook, is it accessable, via Bluetooth, by the Navman/Tom Tom.

TIA, Ian.

Just had a look at the spec sheet for the Samsung and it states gps and GLONASS so yes it has GPS.

HEMA have an app that will run on the operating system of your tablet, Android, HEMA Explorer $49.99 it comes with maps for off line use.

Don't know about your Bluetooth questions, my initial gut feel answer is "unlikely".

Suggest you get onto HEMA and ask them a few questions.

Someone more knowledgeable might come along and answer your other questions.

[sam_d]

This won't help with you more technical questions but I did Boulia to Alice a few weeks back - it's not a challenging track with many turn offs to get lost on.

I used The Alice Springs to Boulia: Series 2, Track 3 of the Outback Traveller's Track Guide (like this one:Alice Springs TO Boulia Series 2 Track 3 BY Greg Walker Paperback 2007 097580023X | eBay (http://www.ebay.com.au/itm/321442034809'ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649)) :)

[V8Ian]

I don't anticipate getting lost, but it is handy to know where one is in case of emergency

[slug_burner]

With respect to GPS accuracy I think that the GPS receiver will have better accuracy than the map details used to show you where you are. This is particularly the case with maps of outback areas where maps are not highly developed and the databases to overlay the roads and waterways contain rough low renolution data.

I think if you took the coordinates from the GPS receivers you would find that they would be well within 100 m and more likely down to 10 m, coordinate system and reference points all being equal.

[Saitch]

[QUOTE=Tombie;2177070]WGS84 is what they should be on :)

QUOTE]
I beg to differ. If theses items are sold in Oz why "should they be" on an American format? GDA, Geocentric Datum of Australia would be a far better system and any decent GPS will give a option!
Steve

[V8Ian]

This won't help with you more technical questions but I did Boulia to Alice a few weeks back - it's not a challenging track with many turn offs to get lost on.

I used The Alice Springs to Boulia: Series 2, Track 3 of the Outback Traveller's Track Guide (like this one:Alice Springs TO Boulia Series 2 Track 3 BY Greg Walker Paperback 2007 097580023X | eBay (http://www.ebay.com.au/itm/321442034809'ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649)) :)
Sam, would it be unreasonable to expect an average speed of 80kph?

[Tombie]

[QUOTE=Tombie;2177070]WGS84 is what they should be on :)

QUOTE]
I beg to differ. If theses items are sold in Oz why "should they be" on an American format? GDA, Geocentric Datum of Australia would be a far better system and any decent GPS will give a option!
Steve


Because many maps are in WGS84... :D

[Tombie]

[QUOTE=Tombie;2177070]WGS84 is what they should be on :)

QUOTE]
I beg to differ. If theses items are sold in Oz why "should they be" on an American format? GDA, Geocentric Datum of Australia would be a far better system and any decent GPS will give a option!
Steve


And the difference ~100mtrs

Sound familiar :)

Let me add to that:
WGS84 and GDA94 are the same (Hema use these)

These replaced older AGD66 and AGD84 which reference out by ~200mt

[Tombie]

Can you answer any of my questions Tombie? Seems you have knowledge of the subject.


Fire away...

[sam_d]

Sam, would it be unreasonable to expect an average speed of 80kph?

I would say an average of 80kph is more than achievable. I did a relaxing drive from Boulia to Tobermoray which took about 4 hours. I took it easy that day and had my camp set up by mid day at Tobermoray Station.

The following day I did Tobermoray to The Gemtree without doing any hard driving either.

The NT side of the Plenty/Donohue is rougher than the Queensland side at the moment but it's certainly nothing that'll slow you down by any great amount. There are a few very short rough patches that you have to slow down for but nothing that'll really hold you up.

I hope this helps!

[V8Ian]

Last year during a Birdsville and Corner Country trip I simultaneously used a Navman My Escape and an entry model Tom Tom, they couldn't agree with each other and neither could agree with the Hema paper map (1:1,100,000?).
This year I will be driving from Boulia to Alice, I have purchased a Hema's Great Desert Tracks Simpson Desert sheet (1:1,100,000). I am considering purchasing this map in digital form.

Q 1. I have a Samsung Galaxy 7" tablet and a Sony Experia Z1 phone, both with a GPS on/off option. Is this a proper GPS or does it rely on the mobile network?

Q 2. Is the Hema digital map able to be downloaded to the above devices and/or the two GPS devices and used as a moving map?

Q 3. All of the above devices have Bluetooth, so if the map is loaded to one device, can it be viewed on the other devices per Bluetooth?

Q 4. If I download the file to my netbook, is it accessable, via Bluetooth, by the Navman/Tom Tom.

TIA, Ian.


Fire away...

Thanks Toombie, you good for coffee on the way home? :p

[Saitch]

[quote=Saitch;2177132]


Because many maps are in WGS84... :D
Hema maps are on GDA94 so, if using an Hema app, I would want to be using the corresponding format. Just me being pernickety again.
Steve

[FeatherWeightDriver]

They'd have to be perfect conditions then as I was using my Android & the property owner was using his phone, which I have no idea what it was but was pretty flash, & they were both about 100m + out in location in a 600 acre open paddock & as mentioned, I had the benefit of knowing exactly where I was in relation to the Cadastre.
Steve

Hmm maybe something else is going on then.

Stationary in an open field even a "poor" GPS should be able to get a fix better than 100m

[Tombie]

Most gps will give a DOP on the Satellite data page.
Looking at it will also let you see the relative position of the "birds".
What you want is a good feed from multiple birds sitting midway between the horizon and straight up (note you can not influence this).

Birds low to the horizon or directly overhead induce greater error in the triangulation.

[JDNSW]

Hmm maybe something else is going on then.

Stationary in an open field even a "poor" GPS should be able to get a fix better than 100m.

Might be something to do with the datum as Toombie has suggested.

I strongly suspect that for much of the published maps of Australia (whether digital or paper) and even after the speroid and datum are correct, the basic information is often not within 100m. And your identification of features, especially cadastral features, could easily have errors of this sort of order. For example, fences are not necessarily on property boundaries, and roads etc may have been realigned since the map was updated.

John

[FeatherWeightDriver]

Agreed (and clarified in my earlier post).

2 possible issues:


the accuracy of the GPS
the accuracy of the maps

[Saitch]

Most gps will give a DOP on the Satellite data page.
Looking at it will also let you see the relative position of the "birds".
What you want is a good feed from multiple birds sitting midway between the horizon and straight up (note you can not influence this).

Birds low to the horizon or directly overhead induce greater error in the triangulation.
Agreed & with a non dedicated GPS such as An IPad I don't know whether The positions are able to be viewed. Not on my Iphone anyway.
Steve

[Saitch]

I strongly suspect that for much of the published maps of Australia (whether digital or paper) and even after the speroid and datum are correct, the basic information is often not within 100m. And your identification of features, especially cadastral features, could easily have errors of this sort of order. For example, fences are not necessarily on property boundaries, and roads etc may have been realigned since the map was updated.

John
John, I was pretty sure where I was as I'd located, by survey, 4 pegs & 4 recovery marks placed in the early 90's & even with a scale factor applied, the phone position would still be poor.
Steve

[FeatherWeightDriver]

Agreed & with a non dedicated GPS such as An IPad I don't know whether The positions are able to be viewed. Not on my Iphone anyway.
Steve

I'm pretty sure IPhone's don't make detailed GPS data available. What you get is what you get.

Android devices, on the other hand, allow full access so you can see what satellites you are seeing, signal quality etc.

This is what I get sitting in my house... please don't tell anyone where I live ;)

https://www.aulro.com/afvb/images/imported/2014/07/1122.jpghttps://www.aulro.com/afvb/images/imported/2014/07/1123.jpg

[Tombie]

Thanks Tombie, you good for coffee on the way home? :p

No worries mate... Coffee, chat... Welcome to drop in... :cool:

[JamesB71]

We regularly do geocaching with the iphone GPS and it always gets us within 5 metres or so.

[V8Ian]

No worries mate... Coffee, chat... Welcome to drop in... :cool:

I'll PM you a day or two before mate, the itinerary lacks structure timewise.

[donh54]

Just my two bobs' worth, but when I was in the Army, the nav training for newbies always started with the observation that you NEVER rely on man-made features marked on maps. Houses burn down, roads get re-aligned, etc. Mountains, on the other hand, don't tend to move much, and nor do rivers, lakes etc (allowing for seasonal flows, tides, etc). Other observation was that, in the event of becoming geographically embarrassed, the map is right, the compass is right, YOU are wrong!
That was a while ago (when I was in the Infantry, Centurion was a rank, not a tank!)