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trad_guy
Mountain climber
Bend, Oregon, USA
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Aug 16, 2011 - 07:50pm PT
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golsen has mocked the 4.1 GPS accuracy claimed by the USGS.
"The images compare the accuracy of GPS with and without selective availability (SA). Each plot shows the positional scatter of 6.5 hours of data (0730 to 1400 UTC) taken at one of the Continuously Operating Reference Stations (CORS) operated by the U.S. Coast Guard at Hartsville, Tennessee. On May 2, 2000, SA was no longer present. The plots show that SA causes 95% of the points to fall within a radius of 44.2m. Without SA, 95% of the points fall within a radius of 4.1m."
Perhaps the GPS units used for this test were not handheld units?
None the less, tracks made by my handhelds over th past several years have plotted exactly on my USGS Quads in Oregon. Junction waypoints have plotted exactly on the center of these road/trail crossings on my topos.
Millions of Geocachers can't be wrong finding the caches hidden in odd places.
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golsen
Social climber
kennewick, wa
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Aug 16, 2011 - 08:52pm PT
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trad_guy,
it just sounded pretty exacting. I did find a couple caches with mine (just for the hell of it), but most recently, mine has not been all that accurate.
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trad_guy
Mountain climber
Bend, Oregon, USA
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Aug 16, 2011 - 10:03pm PT
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golsen-
Thanks!
There was a great jump in connection speed and location accuracy about two years ago, with the advent of new chip and antenna technology from Garmin.
Treat yourself to a new Garmin eTrex Venture hc (very low price at Best Buy)as described above, and it will be more fun to use in the backcountry. You will have computer connectivity (to My Topo's Terrain Navigator and Garmin's Map Source 1:24,000 Topo CD for your part of the USA).
Google map, compass, GPS for 11 free PDF pages on how to use them together.
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trad_guy
Mountain climber
Bend, Oregon, USA
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Aug 17, 2011 - 11:56am PT
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Hello RokJox-
Sorry to say, you are wrong in your understanding of the US Department of Defense Global Positioning System.
This DOD system of ground administered satellites is used to control the geographic positioning of all of our military might, with pin point accuracy. The GPS system is made available for civilian use, accurate to a fraction of an inch.
All current Garmin hand-held GPS receiver Models are equally accurate in the field (to a few meters) and are little affected by terrain and foliage cover.
Garmin and other manufacturers have good tutorials. You can Google DOD GPS basics.
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Reilly
Mountain climber
The Other Monrovia- CA
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Aug 17, 2011 - 12:08pm PT
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Garmin and other manufacturers have good tutorials
Boy, I didn't find any for Garmin. They've promo videos touting how great
their stuff is but step by step tutorials must have escaped my search.
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trad_guy
Mountain climber
Bend, Oregon, USA
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Aug 17, 2011 - 12:28pm PT
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Reilly-
Sorry, I have not looked recently. I know you can download/read their model manuals.
You can try this: Google the three words- map compass gps -for six PDF pages on how to use them together.
Also try the USGS site.
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trad_guy
Mountain climber
Bend, Oregon, USA
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Aug 17, 2011 - 12:35pm PT
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Here is why-
Google- Yuppie 911 devices can take the 'search' out of search and rescue
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bergbryce
Mountain climber
South Lake Tahoe, CA
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Aug 26, 2011 - 06:17pm PT
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FYI... I scored a Garmin Oregon 450 today at rei for $250.
I was planning on getting an eTrex but the Oregon was on sale for like $20 more than the cost of the eTrex. I think it was a pretty good deal.
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rockermike
Trad climber
Berkeley
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Aug 27, 2011 - 12:04am PT
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and if you are going to carry a GPS, take the time to learn how the thing works. I have friends who carry one in their pocket, but besides marking the location of their high camp they don't have a clue how to use the thing.
set the GPS up to show UTM coordinates, and print out your maps with a kilometer grid overlay. Then you can pinpoint your location at any time in a minute or two, no matter what the time of day/ night or weather. Its kind of like cheating.
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Reilly
Mountain climber
The Other Monrovia- CA
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Jan 11, 2012 - 01:07pm PT
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I have the Garmin 62 ST and it does have all the bells and whistles, most of
which are nonsense. But it is highly accurate, virtually waterproof, and
almost readable in the sun. It does eat batteries rapidly and the user
interface sucks big time. Yes, I would recommend this to a friend who wants
to take the time to learn to use it fully. Then they could teach me how.
But the good news is I haven't gotten lost since I bought it!
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Dos XX
Trad climber
Los Angeles, CA
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Jan 11, 2012 - 01:42pm PT
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I use a Garmin 62st in my work, mainly to save money on surveying costs. The "waypoint averaging" feature allows me to measure locations at sub-meter accuracy (most of the time), which is A-OK for rough earth-moving projects. But for recreation use there have to be a lot of perfectly good GPS alternatives that cost WAY less than a Garmin 62. Some folks may be attracted by the built-in topo map feature of the 62st, but I find the built-in topo map to be pretty lame.
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Reilly
Mountain climber
The Other Monrovia- CA
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Jan 11, 2012 - 02:21pm PT
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I find the built-in topo map to be pretty lame.
Man, you got that right! It seems like half the trails I go on the thing
says I'm on a road!
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Sierra Ledge Rat
Social climber
Retired to Appalachia
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Jan 11, 2012 - 04:12pm PT
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Claiming you use a compass to navigate around just tells me you don't get out much. You need an altimeter, too.
I don't know if JLP is an ass, an idiot, or both. What is perfectly clear is that his navigation skills are piss.
I've never used an altimeter or a GPS for navigation in the past 45 years. I get around just fine. In fact, I have even spent days navigating by just using a watch and sun angles.
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Toker Villain
Big Wall climber
Toquerville, Utah
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Jan 11, 2012 - 04:26pm PT
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I just leave a trail of brass casings.
Pretty easy to follow back.
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Banquo
climber
Morgan Hill, CA (Mo' Hill)
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Jan 19, 2012 - 10:14am PT
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I have had 3 or four GPS units over the years/ The first one, a Garmin GPS 38, would take sometimes an hour to hook up and burned through four AA batteries in about that time. I've had a Garmin Forerunner 201 since they first came out and it was great for running and storing a track but not much use for navigation. The 201 is fairly slow, loses signal easily and has a dinosaur serial interface.
For mountain trips, I like to use a map and compass but there are times when GPS would be nice. All I really want is coordinates and altitude. In the mountains, altitude is most useful. Most of all, it should be small, cheap and not cluttered up with bells and whistles.
I recently bought a "Mini GPS" PG03. It is certainly small at 2" by 2.5" and cheap at $40 from Amazon. So far, I think it is what I want. It gives coordinates (sadly only in DMS) and elevation (ft or m). There is no computer interface although it charges with a USB cable. It can store a whopping 16 positions which can be input manually or marked as waypoints. It has a rudimentary compass function which will point you in the general direction and provide the distance to any one of the saved positions. I don't know about battery life yet since I generally only turn it on to check position then turn it off and the rechargeable battery hasn't run out yet. I opened it up and most of the guts are packed in silicon goo but I doubt it is waterproof.
Pluses:
Small
Cheap!
Position
compass
Negs:
3 button interface
No UTM or decimal degrees
compass is slow and doesn't work well when close to the car.
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Banquo
climber
Morgan Hill, CA (Mo' Hill)
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Jan 19, 2012 - 06:24pm PT
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This is the only other GPS unit I use. An Amod AGL3080 GPS Data Logger. It is just a logger and has no display at all. It is intended for GPS tagging photos and comes with software to do that so you can upload photos to google earth. It will record your position at preselected time intervals (1, 5 or 10 seconds)for as long as the 3 AAA batteries last - about 15 hours. At 1 second intervals, it can store up to 72-288 hours of data depending on what data format you choose and up to 2880 hours for 10 second samples but you will have to turn it off and replace the batteries as they run down. Data can be transferred to your computer via USB and displayed in map software, google maps, or loaded into Excel spreadsheet. Good for photo tagging and recording hike routes, bike rides, etc. Seems to be very fast and accurate. About 3.5" x 1.74" x 1". I found it online for $65. The two button interface is a bit tedious for changing the setup. Operation is easy, just turn it on, carry and carry it around and turn it off. there is a waypoint button and an on/off button. Mine is the AAA battery model, the rechargeable one costs more.
Pluses:
Small
Cheap
Simple to operate
Negs:
No data display
If batteries die while recording, the open data file is lost.
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Some-E
climber
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Dec 10, 2014 - 02:21am PT
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Mini GPS PG03
I just bought one on discount and it is somewhat clumsy to use ("Chinese UI"), somewhat messy manual explaining too much on general GPS usage instead of just saying how to set the POI) but despite of that all it feels quite neat. Today I wouldn't pay $40 for this (I paid a whopping $11 USD on today's EUR/USD rate from a local shop, in Finland!). I'd spend double (hmmm that's not enough) on Garmin sports tracker with barometric altitude instead.
I guess the logic can be learned in one day / hour. For example, the POI icon/number may NOT be highlighted in order to be able to set/edit the POI. And yes, the stored POI coordinates can be edited/entered manually. They are stored with date/time info.
No UTM or decimal degrees
I does have three different coordinate modes:
DD*MM'SS.ss
DD*MM.mmmm
DD.dddddd
I wonder if there have been different firmware revisions throughout the years?
For navigating, the "compass needle" is GPS based, but it does have a real digital compass also. That's one thing I'm missing on my phone.
I'm tracking all my sports with phone, so I really don't need a new toy, but this would be for other possible uses. Time will tell. For this price tag I had to grab it.
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