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Hand Held GPS

Printed From: The Fishing Website
Category: General Forums
Forum Name: The Boat Shed
Forum Description: Discuss all things boating.
URL: https://www.fishing.net.nz/forum/forum_posts.asp?TID=5267
Printed Date: 10 Jun 2026 at 7:17pm


Topic: Hand Held GPS
Posted By: KeriBOI
Subject: Hand Held GPS
Date Posted: 28 Jun 2004 at 6:35pm
Im after a HH GPS for my work and thought boaties would be a good start. I dont know if they will be accurate enough though.

Can I get a HH GPS that will be able to mark say a golf hole, and I can come back a week later and find the same golf hole? or is this imposible :)

Thanks
Dane
ps, no Redfinger. NSGC hasnt lost its golf holes due to wetness :)

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Before you judge a man, walk a mile in his shoes; after that, who cares?! He's a mile away and you've got his shoes!



Replies:
Posted By: groper
Date Posted: 28 Jun 2004 at 6:46pm
as far as im aware a hand held gps is not quite that accurate and will be within 2 metres of mark.... and you can come back to a mark at any time (1 day - 1 year)
not sure if the top end of the market is more accurate im only talking about the $300 to $600 range

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I LIKE TURTLES ...........


Posted By: 1000PA
Date Posted: 28 Jun 2004 at 7:22pm

Hi there Keri Boi, I use a "Garmin Plus II" in my 4x4, whilst hunting, and in the boat. I have an additional antenna and 12v connector for power. The unit is portable with its own batteries and antenna and it gives me good data when I want it.

Golf hole is a bit close as there is usually about 2m as said in discrepancy. In 2000 the Americans (Bill Clinton) removed the deliberate error readings and we all got instant improvement. However they kept the right to re-introduce those errors in the event of war! Thus at present we have at times a widening of the specific target for the GPS to track for, its only up to 15m however.

I used mine just yesterday to note a uncharted route in the Coromandels for a hunting trip so we could come out at the same spot yet from another approach angle, and the boys were sure pleased to come out by the 4x4 with the dogs and pig.

There's bigger and better GPS out there but the bucks sure increase with ability. The present day range has a lot of maps, both marine and topographical, and is smaller thus more able to be hidden in clothing till needed.

Ross



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Fishing-4-all-NZ


Posted By: Bender
Date Posted: 28 Jun 2004 at 7:25pm

Suggest you talk to the guys at ENL (Electronic Navigation) - they have some quite new, very high-end Magellan portable units which are the schizz.

 



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Nobody has ever come up with a great idea after a second bottle of water.




Posted By: Woody
Date Posted: 28 Jun 2004 at 8:14pm

Hi Keri Boi,

A mate a Meridian HH. Likes it heaps. You can get road maps for it.

Why the golf course question??

1. Do you plan to put radar guidance in your golf ball to win the hole in one competition ???    Great idea if you are.

2. A lot of Golf courses move the location of the holes around the green.

As above the accuracy is only 2 metres, and can depend on how many satellites you are plugged into.



Posted By: KeriBOI
Date Posted: 28 Jun 2004 at 8:48pm
Just for work as I am one who under number 2 moves the location of the hole on a weekly basis :)

Dane

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Before you judge a man, walk a mile in his shoes; after that, who cares?! He's a mile away and you've got his shoes!


Posted By: obald
Date Posted: 28 Jun 2004 at 9:55pm

The accuracy of GPS fixes is a very complex subject and is given by the formula 'Accuracy = UERE X HDOP' where UERE is the User Equivalent Range Error and HDOP is the Horizontal Dilution Of Position.

UERE is a summation of various things like ionospheric delay, atmospheric delay, user clock error, stellite postion error, something called space pertubations (wobbly satellite orbits) and a few other things and all add up to 19.1m for 95% of the time with SA (Selective availability) turned off (that's Clinton's little prezzie to us all on 01/05/00) and about 62.5m with SA on. HDOP is to do with the geometry of the satellites the receiver is using to get a fix. Ideally the boat (or person) is in the middle of a triangle with one satellite directly overhead and three others on the horizon separated by 120 degree angles . This gives a HDOP of 1. Anything other than this gives a HDOP of > 1 and thus accuracy goes down. Most GPS receivers fail to process a fix if the HDOP is too high (above 2.5 or so I think). All the above is relevant if you are just using the satellites and not using DGPS. DGPS receivers which hook into the better GPS sets are fiercely expensive and are not relevant to  Handheld discussions.

The way I understand it, getting 2m accuracy out of an off the shelf GPS is not physically possible. The yellow Trimble things you see surveyors walking round the streets with in backpacks are accurate down to centimetres I think but don't really fit into the 'off the shelf' recreational category and have to be using some sort of land station (access to which is probably leased from Trimble at $X per month where X is a very large number) to cut out some of the inaccuracies that are inherent in all GPS fixes.

PS I'm sure C2C could usefully contribute here



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Random musings on all sorts of things http://obaldnz.blogspot.com/" rel="nofollow - http://obaldnz.blogspot.com/





Posted By: Coast to Coast
Date Posted: 28 Jun 2004 at 10:32pm

Thank you Obald. You are right. The real world accuracy is 4-8m where we have tested against an exact charted position. Differential will be around 2-3m or a little better. WAAS which is a satellite based differential system is slightly better still but not available here. The surveyors method usually involves a system where the positions are captured and then corrected back in the office off a supplied set of errors compared to time.

The way I used to play golf an accuracy of 4-8m would have been a big improvement......



Posted By: HELLFISH
Date Posted: 29 Jun 2004 at 12:19am

Keri Boi,

Most, if not all Handheld GPS units now offer WAAS which is Wide Area Augmentation System The only problem is, that this service is not based off of Satellite Feedback, it is based off of ground units much like Cellular Phone towers. This service while it sounds great and works great is currently only available in the United States Market. NZ does not have it so your GPS unit will not initialize from it.

New Zealand has a decent GPS Satellite coverage. I am thinking between 3 and 6 Satellites in constallation if memory serves me correctly. The American Government does own the Satellites and they have the International Legal Right to scramble the signals globally "which they do" every time they make a stategic military strike. So what?

All you'll need is in a Garmin Etrex GPS. If you want more bells an whistles you just have to pay more. My Garmin GPS tells you it's margin of error. Most of the time it is around 2-3M. When I have marked a waypoint and gone back, it has been between 3 and 4m off. As the Americans say "Close Enough For Government Work."

My only complaint is that all Handheld GPS units suck down the batteries. Might as well have a unit that only uses 2 batteries instead of the usual four for the same time duration of power.

The only other GPS that was attractive to me was the Silva which had a dead nuts Compass on it that was not Signal Dependant. The catch was that 2 of the three I tested at different stores were defective out of the box. Meaning they would not interface with the statellites and Initialize.

Cheers

HF

 



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I reckon thys hir litel fishin hole jaust aint wut it yuzta bae...


Posted By: Coast to Coast
Date Posted: 29 Jun 2004 at 12:40am
Almost right Hellfish. WAAS uses ground stations to collect the corrections which are processed at a central station then fed back to the GPS via satellite. Its possible to see the appropriate satellite come up on the screen on GPS so equipped.


Posted By: Lethal
Date Posted: 29 Jun 2004 at 1:18am

what do you reckon... is it worth trying to catch a guided missile before it hits its target and pinching the sensitive gps guiding device out of it so we can have better gps marks??????? 

                                           



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Thanks for everything you did for us Eric. may you rest in peace, You were one of the real legends of NZ recreational fishing


Posted By: Coast to Coast
Date Posted: 29 Jun 2004 at 1:30am
Doesn't change the fact Lethal that a better sounder would improve results and most people can't anchor their boat accurately anyway. Which is good for those like you in the 10% and the rest of us that aspire to be.


Posted By: HELLFISH
Date Posted: 29 Jun 2004 at 4:27am

I like the Tomahawk Cruize Missile.

Any chance you could send that thing to Osama Bin Laden?



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I reckon thys hir litel fishin hole jaust aint wut it yuzta bae...


Posted By: Naki
Date Posted: 08 Jul 2004 at 8:42am

Hi.

I see Cheaper Autos have cheap Handheld GPS's for $160.00. Anyone know anything about them. Look cheap & nasty.

I have a Magellan Sportrak and  love it, but it was 3 times the price of the above one. You get what you pay for.



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President of the "Pontoon Owners Club".
I started off with nothing and now I still have most of it left!!!


Posted By: Nsane
Date Posted: 24 Jan 2005 at 8:24pm
Im looking at buying a Handheld GPS overseas..  would they work in NZ?


Posted By: Coast to Coast
Date Posted: 24 Jan 2005 at 8:57pm
Unfortunately almost certainly yes. You'll be on your own though if there's problems.... What are you looking at? Some of the local prices now are so good its barely worth the effort to import.


Posted By: Nsane
Date Posted: 27 Jan 2005 at 3:42am

Im unfamiliar with gps brands.  anything that is portable and proced reasonably.



Posted By: empty
Date Posted: 27 Jan 2005 at 8:08am
ive got a garmin 38 ,a bit old and primative but doew the job on the water

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what happened to the pissing man?


Posted By: Coast to Coast
Date Posted: 27 Jan 2005 at 9:39am
nsane, go Garmin or Magellan. They rule the world of handhelds. Need more information on end use to suggest the model.


Posted By: Nsane
Date Posted: 27 Jan 2005 at 7:11pm
c2c: be using it just to mark fishing spots.  would prefer if you can download or upload gps coordinates as well


Posted By: DiGGeR
Date Posted: 28 Jan 2005 at 8:32am
I have the old Garmin GPS 12. Can't get them anymore, but it is a wicked little unit, I use it for hunting and get under some pretty narly tree cover and still get sattelite locks. As for using it on the boat, haven't had any issues, just that it goes through the batteries, hence why I am installing a cigarette plug in the boat. You could probably pick one up near new off trademe for around $200.

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"What Rock?"


Posted By: Naki
Date Posted: 28 Jan 2005 at 9:42am

Nsane.

I have a Magellan Sportrack and am please with it. The previous model I had was a Magellan 315.

The Sportrack is waterproof, runs on 2 AA batteries that last about 24 hours.

 



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President of the "Pontoon Owners Club".
I started off with nothing and now I still have most of it left!!!


Posted By: Nsane
Date Posted: 28 Jan 2005 at 5:28pm
for the price of $250? can I get a decent handheld gps?


Posted By: scullapint
Date Posted: 28 Jan 2005 at 7:07pm
SupaCheep Autos have cheep nasty gps. Feels very plastic but has a screen with arrows hiway etc as with my magellan 315. Have no idea how it would stand up to practical use. Retail on special was "SFA"..sweet Fa##$K all. -just an option.


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Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time fishing as taking care of the lawn.


Posted By: Nsane
Date Posted: 29 Jan 2005 at 2:09pm

i went to a local tackle shop and they recommended garmin geko 201/etrex/gps72 and magellan 100/200..  need help on the pros and cons on these models.. 




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