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is blazer 12 ok??


Guest K2

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Guest Gliderguy

es, and an additional error of anywhere from 33 to 60 ft from when your unit shows 0.00 distance to goal, you could possibly have as much as 120 ft of error. You could minimize the first 60 ft of error if you keep up with that 3rd decimal place you would have an idea how much further north and west the box should be if you always rounded down when entering the coordinates (roughly 6 feet per thousandth of a minute...)

 

a newer unit might regularly get you within 15 feet or better under good conditions. A really new unit with WAAS should always get you within 10 feet. (assuming you have a good lock on one of the two WAAS satellites.)

 

In summary, you could do fine with the blazer, but you might have to do a little mental mathematics to help overcome its limitations.

 

[This message has been edited by Gliderguy (edited 21 August 2001).]

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Guest Hounddog

Sorry Guys

 

But your statement on GPS accuracy is largely incorrect. If you go to the Magellan website for instance and scan the accuracy specifications for all models you will see the the figure does not vary from model to model. I used a GPS300 for years and found it excellent for accuracy (post SE turn off).

The fact that I was only working with 2 decimal points, was not a hinderance at all.

When I upgraded to a MAP330 I found that the accuracy was exactly the same only now I tended to want to get closer to the location only to find it was way out anyway. I always find it quicker if I ignore figures within 10 metres. Just my personal experience anyway. But check the Magellan site for yourself and you'll see I am correct there.

 

If you really want fine accuracy, try converting figures to UTM. UTM is even finer than three decimals and all GPS units inluding the cheap ones can use this. Then you'll really see how much they wave around.

 

In short, cheap of dear, all GPS units have the same accuracy.

 

Cheers.

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Guest no limit hunter

that statement "all gps units have the same accuracy" is the most obsurd statement i have ever heard. NOT ALL GPS UNITS HAVE THE SAME ACCURACY , the two you mentioned however did, but just becuase that was true of the only ones you have worked with doesnt make it true for all others. The reason your readings jumped around once it was inside the 10 meter bubble was becuase you were, according to the gps unit, at the specified location, even if you were not standing right on top of it. Now if you compare your unit to the newer gps units that have WAAS corrections, you would see that they would be able to put you within a 3 meter circle of the actual location. As you can see its about 3 times more accurate. Proffesional surveyors have gps units that get them within centimeters, which is insane, but so is the cost. Now I dont claim to be a gps wiz but as a geographer and gps user I couldnt let this one slide without a remark.

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Guest AZMark

Having also used both, 3 decimal digits is much better! Although both may fall out of mfg, spec, you will usually do much better than spec if you have good access to the sats. They have to quote a bit of a worse case anyhow.

 

Lets not forget, we rely on those who place to be correct also. Give it a shot, have someone place a cache with a 2 and a 3 digit reciever, then try to recover with a 2 and and 3 digit reciever.

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Guest Hounddog

quote:
Originally posted by no limit hunter:

that statement "all gps units have the same accuracy" is the most obsurd statement i have ever heard. NOT ALL GPS UNITS HAVE THE SAME ACCURACY , the two you mentioned however did, but just becuase that was true of the only ones you have worked with doesnt make it true for all others. The reason your readings jumped around once it was inside the 10 meter bubble was becuase you were, according to the gps unit, at the specified location, even if you were not standing right on top of it. Now if you compare your unit to the newer gps units that have WAAS corrections, you would see that they would be able to put you within a 3 meter circle of the actual location. As you can see its about 3 times more accurate. Proffesional surveyors have gps units that get them within centimeters, which is insane, but so is the cost. Now I dont claim to be a gps wiz but as a geographer and gps user I couldnt let this one slide without a remark.


 

Some people believe in Santa Claus and some in the Loch Ness Monster and still others in this phantom GPS that can actually take reliable readings down to a few centimetres. Hmmmmm but where is this mysterious beast, this wonder GPS. The truth is there is no such thing. At least not available outside of military/space use. The WAAS method may work if you are in the U.S. but in other parts of the world it's plus or minus the same accuracy and this is quoted on ALL models available. Like I said, go to the various web sites and make comparisons. The system used is the same, so the accuracy is the same.

I think most people want to beleive that there GPS is much better because maybe they were fortunate enough to have more money for a more expensive one than others. But the truth is the guy with the base e-trex has just as much accuracy as the guy with the Map330.

 

BTW Cartographers and surveyers have never used GPS equipment to make maps or take elevation readings. They still use the same system thay have used for years certainly long before the GPS came into being.

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nel units are less accurate than 12 channel parallel.

 

Unit that have Differential or WAAS correction will be more accurate than 12 channel parallel units.

 

To get more accurate then this then you have to get access to the coded second frequency that is reserve for military and surveying use.

 

To get more accurate than this you need to take the second frequency in combination with a local fixed receiver to do a very localize DGPS correction.

 

But when it comes down to it an eTrex basic or Magellan 315 is just as accurate as a mega bucks Street Pilot III.

 

Later

mcb

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Guest AmeliaPhoto

I think many of you in this discussion are confusing accuracy with precision.

 

A "two-digit" unit could be dead-on ACCURATE, but the precision could still make it unacceptable.

 

In my experience, the number and placement of the birds affects accuracy MUCH more than the make/model of unit. Precision is a different story, of course....

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Guest Gliderguy

An aquaintance of mine does geological work in South America. They do have "portable" GPS units that give them sub-centemeter accuracy. They use these units to actually track movement along fault lines. Part (probably most) of the accuracy of these units comes from them being statically placed for fairly long periods of time (days), but this "surveyor's grade" GPS is way more accurate than those available to the general public. Knowing this, and knowing that several vendors are very secretive about some of the proprietary software they use in their units, I find it unlikely that a blanket statement to the effect of "all gps units have the same accuracy or precision" can be true. Also having said this, I would bet that for manufacturing expediency, most Magellans within a certain price range would use exactly the same GPS engine. Most Garmins of a certain price range would likewise use the same engine (but maybe not the same chip that Magellan uses!) I think the Accuracy of any manufacturer will be similar up and down their product line because of this. Obviously the precision of 2 vs 3 decimal places is different by definition.

 

"It will work fine, but you will be working under two disadvantages in accuracy:"

 

Yes, this quote in my first post to this thread should use the word precision rather than accuracy.

 

[This message has been edited by Gliderguy (edited 30 August 2001).]

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Hey guys I learn alot from your replys, I decided to buy a Magellen 330X found one with cd,cables and unit for $269.00,If anyone is looking for a new unit go to pricescan.com they find the best price for you.I can't wait to join the fun. Thanks for all your help.

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I have a Blazer 12 I used on 11 finds and it works just fine. It may only have 2 decimal accuracy but it will point you towards the cache and once you pass by the direction switches so you know you went too far. It just reads .00 miles the whole time... I am going to buy a 330 also but only to get better precision for posting caches I plant...

 

quote:
Originally posted by K2:

Hey guys I learn alot from your replys, I decided to buy a Magellen 330X found one with cd,cables and unit for $269.00,If anyone is looking for a new unit go to pricescan.com they find the best price for you.I can't wait to join the fun. Thanks for all your help.


 

 

[This message has been edited by joeld (edited 30 December 2001).]

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