Take Me To GPS School

[hikerbrian]

Not sure, but 24 NE sounds like a 24,000:1 map, which will provide the same resolution. I would expect that, plus or minus a few bells and whistles, they're probably the same.

 

[iAmKrzys]

Does anybody have any recommendations on maps to download?

I am a big fan of OpenStreetMap (as user & contributor) and I use OSM for maps of hiking trails on my Garmin eTrex 30 (although to be honest I often look for places where I know/guess that there are trails yet to be mapped on OSM.)

If you have a recent Garmin model you can get OSM maps pre-compiled in Gramin format. It really boils down to 3 fairly straight-forward steps:
1) select map region from a drop down menu at http://daveh.dev.openstreetmap.org/garmin/Lambertus/latest/kml/kml.html and download it. The region gets highlighted when you make a selection so you will see what map area you will get.
2) copy it to /Garmin folder on your device (I use memory card on my eTrex for this purpose) and
3) enable the map for display via map options -> Select Map menu.

You can read more about this and other ways to get OSM onto your Garmin gps here:
http://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin/Download

I guess the biggest drawback of this version of OSM map for Garmin is that it does not have contour lines. Hence, I also keep Garmin 100k map on my gps, but the street & trail data on it looks like it hasn't been updated in 50 years or at least in the version that I have. I hear that 24k maps are better in this respect and it makes sense to me - otherwise who would want to buy maps covering much smaller area for same amount of money?

There are other map sources too. You may try https://www.gpsfiledepot.com/ that has a good number of maps.

If you have maps in PDF or JPEG format you may use them to create what Garmin calls "custom maps." A couple of years ago I had a presentation on this subject to local geocaching community and a copy of this presentation is still available on-line here: http://centraljerseygeocaching.net/...&view=topic&catid=8&id=17071&Itemid=188#17646

 

[DougPaul]

I recommend that new users read the manuals (the online copies from the Garmin website are often better than the ones that come with the GPS)*, traverse the menus to see what is there and to become familiar with it. (You don't have to change anything right away...) Also play with the GPS by using it when you don't need it to learn how to use it. The practice will be invaluable if the time comes that you do really need it.

* The manuals focus on how to operate the GPS, but don't say much on how to navigate using a GPS.


I have and use Garmin 100K and 24K topos. As iAmKrzys noted, one can also get free Garmin format maps from https://www.gpsfiledepot.com/. IMO the Garmin maps are better, but cost money. If you buy topo maps from Garmin, you will get more map for your money if you buy the DVD versions rather than the memory card versions. You then use a computer running BaseCamp or MapSource to load the maps into a GPS or memory card. (I believe you get the same maps either way.) The DVD topo maps are not locked (to either a GPS or a memory card) and can be used on multiple GPSes.

Gpsfiledepot also has instructions on how to get legal free copies of BaseCamp (and MapSource for the older model GPSes) to load the maps into the GPS.

Doug

 

[CaptCaper]

Assuming I know ZERO about GPS and how it works......If a guy (or gal) came to those of you in the know and said:

"Where do I go to begin to learn how GPS works?" Garmin Montana 680. Not sure if I will keep it. Don't have a clue of its capabilities or if I want it. Very much euphoric and willing to learn but not so sure it's for me. I will wait and see. It is kinda heavy....But I wanna learn.

Any tutorials you can recommend? Basics thru more complex. Manual isn't so clear when you are starting from ground zero.

Welcome to GPS ...you will have to read read practice practice.. keep practicing or you'll loose it. I've used GPS's of many types and kinds since 1995...I was one of the first if not first to use an external antenna on it for hiking so it can record perfect data. I save all data via Mapsource and or BaseCamp.. Use them again for going back on a hike or revisiting specifics of a past hike. I use Garmin's maps only in conjunction with Base Camp Mapsource and NG State series. That's all I need for what I do.
The Montana is a perfect unit now. Garmins best ever for hiking a few ounces over the Oregon ...don't return it. Get to know it. I used the Montana 600 for years and many hikes (also snowmobile's) and now use the 610 which has Glonass....I like Glonass better... I've compared the two with the data data (old tracks) and found the Glonass achieves a over all better fix in the long run on all the trails and conditions I've been on over the years. But the 600 did a fine job still. I use an external antenna of small size now (combo glonass/gps) as I always have and run it all day in a pouch on my front chest strap.
Turning down the light. Locking the touch screen and leaving it on trip computer gives a very long battery life. Also in winter or very long hikes into the wilderness I carry 3 Lithium batteries in case Garmin's fails.
My two cents and recommendations... good luck..

 

[Stan]

To add to this inquiry, what do those with good practical as well as technical GPS knowledge feed about DeLorme's inReach which combines navigational functions with satellite communications and what promise do you expect from the acquisition of DeLorme by Garmin? BTW, I've had some assurance that DeLorme's print media, especially the atlas/gazateers will continue as they acknowledge the great public popularity.

 

[BISCUT]

I've been playing with the unit and find it pretty intuitive. I did read the online manual, but as mentioned, it is a how to on using the unit, not so much as how to use a GPS. For instance, how to plot a trail, the when and why of dropping waypoints, etc...

Started to check out basecamp software. Looks pretty good. Feeling good about this now.

 

[DougPaul]

I've been playing with the unit and find it pretty intuitive. I did read the online manual, but as mentioned, it is a how to on using the unit, not so much as how to use a GPS. For instance, how to plot a trail, the when and why of dropping waypoints, etc...

Using a GPS isn't that difficult in concept--it's mostly just the details. The core GPS finds your location (including altitude) and the time from satellite signals. The user interface computer displays the location and tracks on a map display and can give you your distance and bearing to a waypoint. It can also string some waypoints into a route and lead you along them. If you are familiar with point-to-point navigation (such as buoy-to-buoy navigation) it will be pretty familiar.

Started to check out basecamp software. Looks pretty good. Feeling good about this now.

BaseCamp is ok but many prefer MapSource for looking at maps. (A number of people use BaseCamp for interacting with the GPS, save the tracks and waypoints as gpx files and then examine them with MapSource.) I suggest that you install both give them both a try. I personally use MapSource to look maps pretty often.

Doug

 

[iAmKrzys]

You can use GPS at many different levels. What you get out of it will depend on what you need and how much you want to learn.

• Level 0: You don't install any maps. You can still see your tracks as you walk around. It doesn't seem like very useful until you go bushwhacking and see no reference points and want to get back to where you came from. Or maybe suddenly a dense fog descends and you decide to return back to your car but can't see more than 30 feet away.
• Level 1a: you learn how to read coordinates from your gps and can tell someone your exact location (e.g. when you call 911) or you come across a disabled hiker and you get no cell coverage where you are but later need to tell rescuers where this person is (the situation described in Edmunds Col Fatality comes to my mind here.)
• Level 1b: you learn how to mark a waypoint, so that you don't need to record coordinates in 1a) on paper. You use this to mark the location of your car or trail intersections & viewpoints along your hike.
• Level 2a: you learn how to mark a waypoint from coordinates you get from somewhere else e.g. Internet, another person, or a map and how to navigate using this waypoint to get to the place it indicates.
• Level 2b: you learn how to transfer waypoints either from BaseCamp or by copying gpx file to your gps (bread & butter of geocaching)
• Level 3: you learn how to transfer your tracks back to BaseCamp and you analyze your hike statistics such as moving average, cumulative ascent etc
• Level 4: you figure out how to install maps (possibly multiple sets) on your gps and learn how to switch between them while in the field.
• Level 5: You learn how to transfer someone else traces in gpx format to you gps and use them to follow in their footsteps (e.g. on a bushwhacking hike)
• Level 6: You learn how to create routes in BaseCamp and transfer them to your gps, so that you can follow them on your hike.
• Level 7: You figure out how to use other bells & whistles in your gps such as electronic compass (it has to be calibrated before use), "sight'n'go" etc.

 

[LavaFalls]

To all talking about a GPS, a Garmin...What happens when your GPS's batteries run out? What happens if you don't know how far you have to hike to your destination? What happens if you don't know your elevation ascent/descent? Your heart rate, your number of steps per hundred feet elevation gain?
Knowing how to read a trail map, use a compass, knowing when those thin lines on maps (the contours) are bunched together that means you will be climbing/descending a steep slope. We all hiked a few years ago to enjoy the trails, the peaks, the "views from the top". Now we are all obsessed with gadgets that add extra weight to our packs. Sad to say this is the new "normal".
Lavafalls

 

[dailey7779]

To all talking about a GPS, a Garmin...What happens when your GPS's batteries run out? What happens if you don't know how far you have to hike to your destination? What happens if you don't know your elevation ascent/descent? Your heart rate, your number of steps per hundred feet elevation gain?
Knowing how to read a trail map, use a compass, knowing when those thin lines on maps (the contours) are bunched together that means you will be climbing/descending a steep slope. We all hiked a few years ago to enjoy the trails, the peaks, the "views from the top". Now we are all obsessed with gadgets that add extra weight to our packs. Sad to say this is the new "normal".
Lavafalls

This is an April Fools comment, correct??!! If not...

I'm going to go out on a limb here an say that everyone who has posted on this topic might just have an understanding of how to read a map and what those thin lines are all about. I'm also going to assume they enjoy the trails, the peaks, and vftt. I don't have a spiffy GPS, and I've been to some off the beaten path places, but I definitely will get one in the future and this thread has been helpful. The only new "normal" is the growing number of hikers who complain online about everything.

-Chris

 

[TJsName]

What happens when your GPS's batteries run out? A: You replace them, or continue without using the device.
What happens if you don't know how far you have to hike to your destination? A: You keep hiking until you get there.
What happens if you don't know your elevation ascent/descent? You keep hiking until you get there.
Your heart rate? A: This can easily be calculated without a GPS.
Your number of steps per hundred feet elevation gain? Not really relevant.
Knowing how to read a trail map, use a compass, knowing when those thin lines on maps (the contours) are bunched together that means you will be climbing/descending a steep slope. A: This feels condescending.
We all hiked a few years ago to enjoy the trails, the peaks, the "views from the top". A: Some people here are new to hiking, and many more are new to winter hiking. The hiking for enjoyment/exercise is still a primary motivating factor.
Now we are all obsessed with gadgets that add extra weight to our packs. A: This poll suggests that we aren't all obsessed with GPS. As for gadgets in general, there is a fairly constant 'weight vs. functionality' debate that takes place. Writing off all gadgets as extra wight is an oversimplification.
Sad to say this is the new "normal". A: Your entire post feels like an appeal to a sentiment that technology is bad, which is unfortunate. It's always good to question new technology in thoughtful ways, but the questions have to be fair.

I personally use the GPS that's built into my phone in conjunction with an application/service I subscribe too. I track my trips, which has some novelty to it, but I mostly like how it shows me where I am on a topographical map. It's helpful, but not vital most of the time; however, I did use it this summer when my dog chased a pine marten into the woods. I was able to search for her aggressively using the detailed map to see where I had searched already. That wouldn't be easy to do with a paper map. I still bring a paper map and compass as back-up, but for me the greater convenience and ease of use of my GPS justifies the extra weight.

 

[CaptCaper]

This is an April Fools comment, correct??!! If not...

I'm going to go out on a limb here an say that everyone who has posted on this topic might just have an understanding of how to read a map and what those thin lines are all about. I'm also going to assume they enjoys the trails, the peaks, and vfft. I don't have a spiffy GPS, and I've been to some off the beaten path places, but I definitely will get one in the future and this thread has been helpful. The only new "normal" is the growing number of hikers who complain online about everything.

-Chris

Good post..
I only have a gps for a gadget myself...well also..compass and crampon's..
Being I made a living navigating to ship wrecks,other ports,etc. well before GPS I must say in short there are a lot of folks who would be alive today not only in the Whites but every where if they had even the simplest GPS...that's a fact.
I love to comment " The space shuttle would could never fly with just a map and compass". Dead Reckoning is a whole other topic.
Most folks who post negative about gps have no clue about it's use being they've never walked a mile in those Moccasins. So I excuse them. Years ago there were many who called it a toy here. Now so many have them and I'm so glad.. I do have to say it's obvious that learning how to do map and compass navigating should always come first. Hope everyone has sense enough to do so.
Be safe.

 

[skiguy]

Before this topic goes off on a rant that can be found elsewhere in this forum we can all go back and focus on the OP. Lots of good info on this site on how to learn how to operate a GPS. Also there is always DougPaul to come to the rescue if no one else can figure it out!

 

[Nessmuk]

I have commented many times on this topic, here and elsewhere. I will only say that the GPS can be both a tool and a toy, depending on how it is used and requirements for use. Just understand that navigation is a multi-element system process. Some want to learn to navigate as a prime experience in itself, when time honored methods are best for the purpose and result in the greatest satisfaction in the desired experience. Others just want to get from point A to point B with minimal effort, when using the most advanced electronic tool is best to accomplish the JOB at hand (think surveying and SAR, to name only two). Understanding the basic tenants of navigation, which most definitely includes using the most advanced tool that resides between your ears along with your eyes is always a fundamental basis for navigation. The process (think tools or toys as separate functions) can be supplemented with all available electronic knowledge sources, is what you may then decide to use. Observational navigation (eyes and brains) with available map and compass goes without saying as necessary for all navigators, regardless of other assists. Want to add GPS, then go ahead. Just please don't depend on any method that does not include how to get out of situations without using the gray matter as the ultimate educated resource.

 

[DougPaul]

IMO, the smart navigator uses several methods of navigation simultaneously. If they disagree or one fails then one should figure out what has happened before continuing. We should note than any method can fail for one reason or another...

For the modern land navigator, these methods often include map, compass, and GPS each of which has its own strengths and weaknesses. Other methods include following trails, dead reckoning, the sun, the moon, the stars, wind, terrain, vegetation, and local knowledge to name a few.

We should note that people used to navigate without the use of accurate maps, compasses and/or GPSes and at least most were able to reach their destinations...

Doug

 

[CaptCaper]

IMO,

We should note that people used to navigate without the use of accurate maps, compasses and/or GPSes and at least most were able to reach their destinations...

Doug

Yea.... Ask the Pilgrims..they made it..they were only 700 miles or so off.

 

[Nessmuk]

It's about more than just when one method fails, it is knowing, and knowing early when one fails, and more than that what to do next. Errors will be made by any experience level of navigator. The trick is having the ability to catch errors early (including rapid initial discovory of failing methods and equipment), and making appropriate corrections. I tell my Nav students that one error is easily correctable, but make a compound error and your problems become incredibly tougher. My initial AF instructor long ago told me something I never forgot: all navigators make mistakes, but the difference between success and failure is how early those mistakes are discovered and corrected. The same applies to all forms of navigation.

DougPaul listed a number of clues to aid in navigation, and the idea that all should be taken into account. There are others not listed, many of them. Pay attention to all that is around you, most of which can be easily seen and interpreted long before you get into trouble. Learn what nature tells you, along with map and compass and finally GPS. If any one element does not make sense, do not proceed until you understand why and how it fits with all other observable and observed data.

 

[BISCUT]

I haven't made my mind up 100% but pretty close. I'm most likely going to keep the unit and learn it! Similar along the lines of DougPaul's comments, I don't see why any paper map user (ME!!) would have any negative sentiments toward the use of GPS. It's an additional tool. I really like the fact this unit gives me lots of data I enjoy knowing like altitude, time to next marker, total time expended, and a ton of customization options for your dash board.

 

[Nessmuk]

About two years ago I along with a couple of others experienced in land navigation techniques began teaching a pilot course for a division of NY Homeland Security. The course was to be geared toward law enforcement officers of all kinds, from prison corrections officers, to sherrif's offices, to major state special operations forces. SAR team and advanced EMT members are also invited to attend.

The initial course sessions focused a lot on what I have always taught separately, basic concepts of observational navigation and map and compass, and map plotting in class and in the field. We had quite a bit of GPS training as well in the second half of the 2-day program. We as instructors soon learned that the time available for GPS wasn't working out to be very productive, due to differences in individual agency's particular GPS device, and that the students hadn't yet perfected their own ability in basic land nav techniques. So we essentially abandoned the GPS field portion of the course, leaving that section to introductory GPS concepts only, with exercises left to the student to learn by them selves, incorporating what we taught them in the basic field course. We felt we really needed to use the time available to get the students as proficient as possible in more traditional basic land navigation skills, and they could then better learn their specific GPS applications on their own. So that is how the formal course is structured today.

 

[CaptCaper]

I haven't made my mind up 100% but pretty close. I'm most likely going to keep the unit and learn it! Similar along the lines of DougPaul's comments, I don't see why any paper map user (ME!!) would have any negative sentiments toward the use of GPS. It's an additional tool. I really like the fact this unit gives me lots of data I enjoy knowing like altitude, time to next marker, total time expended, and a ton of customization options for your dash board.

Just remember the Altitude in GPS's are not as accurate as the horizontal data is. The horizontal data I'm talking about is location and track logs,etc. The altimeter has several options. The unit from Garmin comes in default settings for average adjusted readings. The unit takes gps elevation readings and barometer readings and averages it out. Which is best for the long term or short term newbee. I calibrate and re calibrate during the hike for a better or more true ascent figure. But If you warm it up say for a half hour or so before the hike it will give decent results. And usually by the time I get to the summit the elevation is close always.. So be ware on these readings. It's not uncommon for the gpsr's with Altimeters to start out reading wrong elevations or when you come down sometimes until it adjusts according to the algorithms Garmin has patented. Changes in pressure with a front coming in changes elevation readings. A .05 change in baro pressure as when low or high is coming in can give a 45 ft difference in elevation reading.
Otherwise if the Montana does give a excellent position and track log to work with.

Modern Barometric Altimeters

Modern GPS receivers (GPSr) often include a barometric altimeter. Barometric pressure is essentially a measurement of the weight of the air above a given point. When a high pressure weather system is in the area, barometric goes up because the air is more dense or heavier - this is what pushes the rain clouds away. Low barometric pressure usually means more clouds. Barometric pressure is typically reported in inches of Mercury (e.g., 29.92 inHg) or in millibars (e.g., 1013.25 millibars).

A barometric altimeter is tool that measures the amount of air pressure at that location. A GPSr with a barometric altimeter can provide more accurate elevation data (sometimes within 10 feet or so) than it can obtain from using the GPS satellites alone (sometimes within 100 feet or so - yes, elevation accuracy from satellites kinda sucks, and it gets worse as your elevation increases because you're closer to the satellites making it harder to determine your distance from them).

A GPSr with a barometric altimeter knows that if the pressure decreases, that there is less air above it. Thus one of two things has occurred - either the GPSr has moved to a higher elevation OR the natural barometric pressure for that location has decreased due to weather changes. The problem is that the GPSr doesn't know which has occurred.

Altimeter Calibration

To get accurate elevation readings, the GPSr must be calibrated so it can equate a pressure reading to an elevation.

There are four ways to calibrate the GPSr barometric altimeter:
1. Enter the KNOWN elevation when your barometric pressure is unknown.
2. Use the GPS-calculated elevation when your barometric pressure is unknown.
3. Enter the ADJUSTED barometric pressure when your elevation is unknown.
4. Let the GPS-calculated elevation help auto-calibrate the barometric altimeter over time.

Method #1 tells the GPSr that the currently measured barometric pressure in the GPSr is what should be expected for that exact elevation.

Method #2 does the same thing, except that it uses the rather inaccurate (+/- a couple hundred feet) GPS-calculated elevation.

Method #3 allows the GPSr to determine the current, accurate elevation by determining the difference between the measured pressure in the unit and the sea-level adjusted pressure you provide.

Once the GPSr has a good idea of what the accurate elevation is for the internally measured pressure, changes in pressure can more accurately be represented as increases or decreases in elevation. For example, a pressure change of .01 inch of mercury as measured by the internal barometer equates to ~10 feet of elevation change.

But, your GPSr assumes that the the only thing that changes pressure is it moving higher or lower - it ignores the fact that weather also affects pressure. Thus, if the atmospheric pressure around you changes, your elevation accuracy will suddenly be out of whack. This means you should only calibrate your altimeter using pressure or elevation if you want increased accuracy over short periods of time (shorter if the weather/pressure changes) and if you'll remain within a small geographic area (because changing locations is more likely to result in an atmospheric pressure change).

So which calibration method is best?

Methods #1 (known elevation) or #3 (known pressure) arguably provide the same level of accuracy, though using a known elevation is typically better because it is a finer value than the measures used for barometric pressure. Either way, the calibration values should only be entered outdoors, out of the wind (which can arguably affect barometer readings), and once your GPSr has been on, immobile, and well established for some time. All GPS altimeters require good GPS reception AND accurate pressure readings. Using the GPS altimeter in your car or indoors will not result in high accuracy - and could result in VERY poor accuracy (e.g., 1000's of feet off).

Letting the GPS auto-calibrate the altimeter is BY FAR the easiest - and by far the most accurate over long periods of time or distance or weather. This method uses the GPS-computed elevation to hone in on a 'best-guess' elevation and then uses the altimeter to help maintain accuracy and consistency of the displayed elevation over time. Most units recalibrate every 15 minutes using this method. Once your GPS location is well established, the accuracy of auto-calibrated altimeter readings are only slightly less accurate than manually calibrated readings. The advantage of auto-calibration is that you can be assured that natural pressure changes are not distorting elevation readings over time.

In short, there really are very few advantages to manual calibration over auto calibration. Perhaps the only notable advantages are increased accuracy within a short period of time after proper calibration and that most manually calibrated GPSr units can provide high accuracy almost immediately after turning them on - you don't have to wait for the unit to establish your position before getting a highly accurate elevation reading (e.g., the unit can read the barometric pressure much faster than it can triangulate your position).

If you calibrate your GPS altimeter with known pressure or known elevation, you must turn off "Auto-calibrate" function in your GPS otherwise it will ditch your entered value and go back to the best-guess GPS elevation in a matter of minutes. Most units prompt you to turn this off after manual calibration. But be sure to turn this function back on later otherwise the reported elevations will likely be WAY off because the pressure will likely have changed.

Some tips on using pressure calibration

If you choose to calibrate using a known pressure value, be sure to use sea-level adjusted pressure readings(sometimes referred to as ASL, MSL, or elevation adjusted). You can get these from local weather reports and from airport METARreports. METAR reports for your local airport are available here - just find the numbers after the A and put a decimal point in the middle. For example, my local airport METAR contains A3035, so my current sea-level adjusted pressure is 30.35 - or 30.35 inches of mercury. METAR and weather station pressure values are typically accurate for perhaps 100 miles from the reporting station/airport (naturally less if the weather is changing).

Your GPSr expects an elevation adjusted pressure. The pressure can typically be entered in inches of Mercury (inHg) or in millibars.

If you're using a home weather kit, barometer, or get the pressure from another GPS system or weather station data feed, these will typically NOT report elevation or sea-level adjusted pressures. Using these values will cause great inaccuracies - higher inaccuracies the higher your elevation. Because one inch of change in mercury represents ~1000 feet of elevation, if you live at 5000 feet elevation, your elevation adjusted pressure might be 30.10 inches, but a barometer would probably show a local (unadjusted) pressure of 25.10 inches. If you enter 25.10 inches into your GPS, elevations shown on your GPS will be off by 5000 feet!!!

Some tips on using elevation calibration

The optimal method for calibrating using a known elevation is to use an elevation benchmark. Go tohttp://www.geocaching.com/mark/ and enter your zip code and try to find a benchmark you could use (U.S. only). Be sure to look for one that has recently been found in good shape (has a smiley face icon) and that has an adjusted (e.g., very accurate) elevation (check the description for "Altitude is ADJUSTED"). Benchmark elevations are VERY accurate - usually within a few 1/10s of an inch - pretty remarkable considering most were placed in the 20's and 30's.

Because the GPS unit itself is only accurate to within 10 or so feet of elevation at very best, you may be just as well off using a good topographic map or even Google Earth to determine your location's elevation for calibration. One good method is to use a benchmark initially then use that to determine your home's elevation - then use this elevation to calibrate your unit each time you leave home. Be sure to measure an elevation outdoors - taking it inside or calibrating inside will ruin your accuracy.