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  1. #1
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    Looking for a GPS?

    I was bored today, so I decided to write this about GPSes...hoping it will get stickied for some of the oft-asked questions on this board.

    So you find yourself wanting a GPS to take on a ride? First thing to be aware of is that generally, consumer-level GPS receivers fall into a few categories.

    There are car GPS receivers.
    There are general outdoor receivers.
    There are fitness receivers.
    There are specialty receivers.
    Then there are cell phones.

    I won't really address car receivers or specialty receivers (golf, dog tracking, etc) as they are probably the farthest from ideal. Some might work in a pinch, but if you really want a GPS, get something else. A general outdoor model can be had for $100 usually. Sometimes less.

    I also won't really address a lot of specific models, as I'd prefer this topic to remain relevant as technology improves.

    First, a little bit about how GPS works in the first place. A GPS does NOT send any signals to satellites. The GPS receiver ONLY receives signals from GPS satellites. The quality of this signal depends on a lot of things. It could be impacted by solar radiation in space (solar flares). Since the signal passes through the atmosphere, atmospheric conditions can play a role (clouds, rain, all sorts of things). Terrain plays a role, since most satellites are in the southern sky (northern hemisphere) or northern sky (southern hemisphere, for you kiwis, aussies, and others below the equator). If you are on the north side of a mountain in the northern hemisphere, that mountain will interfere with your reception because the mtn is between you and the satellite. Then there's signal scattering. This is usually from vegetation, but can also happen from terrain, buildings, or anything else only partially in the way. Basically, part of the signal from the sats gets through to your GPS, but some of that signal bounces off something before it gets there, adding confusion. Older GPS receivers could not process this very well, lending to a lot of dropped signals. Newer ones do a much better job of it and have fewer problems. The reason this is confusing to the GPS is because the satellites transmit the time from atomic clocks on board. If parts of the same signal arrive at different times telling the GPS they're both the same time, it presents a bit of a conundrum.

    Furthermore, access to the GPS system only costs you the price of a receiver. There are no subscription fees. The government has the capability to scramble the signal (the original use was military after all) but wholesale scrambling of GPS signals was stopped in 2000 (selective availability, it was called). That's when GPS receiver tech took off. Different countries have their own GPS systems, and there are all sorts of technical details I won't go into. This is for newbies who don't have a clue.

    GPS receivers come in many flavors with lots of different feature sets. First, I'll address what I call 'general outdoor receivers'. This type has a wide range of useability, from hunting, geocaching, hiking, mountain biking, paddling, all sorts of things. They are typically shaped to fit well in the palm of your hand, though various mounts are available aftermarket to attach them to nearly anything. Because they're shaped for handheld use, button layouts are conducive to that use, too, and these can get kinda big. Some have touchscreens and integrated cameras now, among other things. These features are fancy bells & whistles at this point. Other, navigationally important features include an electronic compass (2 or 3 axis), and a barometric altimeter.

    As to how these options work, first I'll talk about the compass. An electronic compass allows the compass feature of the GPS to function more like a real compass. Without this feature, the compass can only tell you what direction you are headed WHILE YOU ARE MOVING. With an electronic compass, you can stop to use the compass, and see which direction is which (or see which direction you NEED to go). This is handy if you travel off-trail (mostly relevant for hiking and hunting, rarely for biking).

    The barometric altimeter is a more sensitive way to determine altitude. Without this feature, the GPS calculates your altitude based on distances/directions to satellites. To do so, it requires a signal from at least 4 (assuming the geometry of the arrangement of the satellites in the sky is ideal...more than 4 if those satellites are clustered in one part of the sky). There is a pretty significant amount of error inherent in this method because all the factors that impact GPS signal quality impact this calculation, too. The barometric altimeter is a separate measuring device in the GPS that uses air pressure to determine altitude. Its accuracy is dependent on calibration frequency (did you calibrate it a month ago or right before you started your trip?) and weather. An incoming or outgoing weather system will cause the barometer to drift, showing slightly higher or lower elevations. However, calibrating more often at known elevations can minimize drift. What's extra useful here is that knowing this phenomenon happens, you can use it to predict the weather.

    Pretty much all outdoor receivers have similar feature sets. Only a few features are unique to a certain brand or model, and the available features usually changes over time, too. Right now, the ability to upload aerial imagery is a pretty unique feature to one brand of GPS. Eventually, all brands will probably include this feature. Same with touch screens. Integrated cameras aren't unique to one brand, but not all brands have adopted them yet. Some brands will accept basemap data that is freely available. Some require proprietary maps. If considering a general outdoor GPS, look at the extra features like this, more than the basic GPS mapping functions. It's the extras more than anything that mean the difference between one GPS and another.

    Now for fitness receivers. These types are mostly intended for folks who want to improve their training and keep track of races and such. So far, there are wristwatch style and bike-specific models, though I wouldn't be surprised to see some company come up with a new idea down the line. Most of these types of receivers sacrifice mapping capabilities (they still record a track or course of your activity) at the expense of fitness options. These often will display more 'metrics' on the ride, essential information for someone doing the same activity repeatedly and tracking improvement. Another option would be an included heart rate monitor. The advantage of including the HRM with the GPS is that you can track heart rate according to elevation or speed or any other number of metrics the GPS tracks. With separate devices, it is difficult to impossible to relate these two data sources. Some cycling specific receivers include an additional speed/cadence sensor. This sensor is not (currently) used for speed data unless there is no GPS signal. It is primarily used for cadence data, or to allow the GPS to be used indoors on a trainer. A limited number of fitness receivers include the mapping capability of a general outdoor receiver. This is good for people who intend to navigate (either roads or trails) in addition to tracking fitness. These receivers allow users to upload the same types of basemap data as general outdoor receivers.

    Fitness receivers also have optional feature sets including a barometric altimeter like general outdoor receivers. This allows the GPS to report more accurate elevation values and report elevation gain/loss (which can be important to fitness users). A note on this, however, as it comes up often in the forums. Different software handles this data differently. Some software simply reports these elevations just as the GPS collected them. Some programs will apply 'corrections' to this data. Some programs throw it out entirely and report their own elevations based upon the elevations your position corresponds to on a digital elevation model. It's important to realize that these values can be quite different from each other, and to recognize that the developers are only trying to provide the closest estimates to actual elevation possible. Right now, there does not seem to be a single 'best' method, so we just have to live with the discrepancies. If you want to talk up your ride, it would probably be best to share the highest of the reported values to impress your buddies most. Otherwise, I'm not sure it matters that much.

    The final type of GPS I will address is the cell phone. I'm only addressing it at all because with the advent of the iphone, it seems an awful lot of folks want to use it as a training computer. To me, a GPS in a phone is a better navigational tool for the city, not the woods. To use a phone GPS on the bike, you have two options. The first is to toss it into your pack and ride. This is probably safest for the device, assuming you at least put it in a ziploc for rain protection in the event of a sudden downpour. The other option is handlebar mounting. This typically requires a protective case for the phone plus the mount itself. It seems a great deal of options on the market are unsatisfactory, so choosing the right one can be difficult.

    Phone GPSes increasingly use touch screens and have integrated cameras, also, like some newer general outdoor receivers. Phone GPS receivers, however, lack barometric altimeters, and only within the past few months has apple introduced an electronic compass. As far as I know, there are no optional heart rate monitors or cadence sensors that will work with a phone GPS.

    Phone receivers are heavily dependent on software for data collection/reporting. Few if any have adequate included software, so a user must use an additional program (some cost extra) for GPS data. Reported battery life is also dependent on the program. Some programs seem to drain the battery rapidly, while others make better use of the battery. None give run-times as long as GPS specific receivers, so battery life is still a concern for all-day rides.

    The quality of the phone GPS receiver's chipset is also questionable. Most use a combination of satellites AND cell phone tower triangulation to report your location, but provide questionable results when cell towers are not within range.

    Lastly, depending on the program used, basemaps may not be available if cell reception is lost. While a specific GPS receiver is able to store basemap data, some cell phone GPS programs do not store basemaps, they simply use a live download from Google Maps or other service.

    Despite the limitations, many still use cell phone GPSes on their bikes, and some have been able to overcome those limitations. However, contrary to a specific GPS that does not require service fees, a cell phone GPS requires a service plan that includes GPS and data access. If a user already has a cell phone with a GPS, it may be useful to try (taking into account the need to protect the device from rain, dust, and shock) before buying a specific GPS. However, a cell phone GPS has many limitations when compared to a specific GPS, and certainly more advanced users often want those additional features.

    Software to use with your GPS data will get covered in another topic. Software is a HUGE topic and one person cannot cover it all.

  2. #2
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    Good stuff Nate, well done!

    Is there a mod in here to sticky it?
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  3. #3
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    Good read. Thanks for the info. As a new old dude getting baqck into shape, I found it informative.

  4. #4
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    good info for newbies like myself.

    Now taking advantege of your kindness, I would like to ask you a question

    I like to look for new trails on google earth before I actually go ride them, but most of the times they are not easy to memorize at the first time with out getting lost every now and then lol, since there are lots of turns involved.
    I was wondering if there was a way I could trace those trails on google and then upload `em to a gps, to just follow them on the screen, and if there was, which gps unit or units would do the job?

    I would be really thankfull for that info.

  5. #5
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    Google Earth works with .kml or .kmz formats. A limited number of new GPS receivers can handle them without conversion. The most useful format for you will be .gpx. You can save as .kml and then convert to .gpx or you can use a different program with native .gpx support. There are lots of discussions in here about computer software to use with a GPS. Most can use .gpx files.

  6. #6
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    Not all the comments apply to all phones.

    I just got an LG Incite unlocked, no-contract smartphone for $150 ("last year's model"), and use it on T-mobile with no data plan (and no data charges). It has a true GPS built in, and there is a tweak available to prevent it from trying to use "aGPS" which would use cell tower triangulation to get a quicker lock.

    I will not attempt to handlebar-mount this...it's got a pretty small screen that is hard to see outside, anyway. I'll keep it in a pocket or pack to consult as needed, or possibly use headphones or a bluetooth headset to be able to hear voice prompts.

    I have OziExplorer running on it, which I've used for a long time with USGS topo maps, and I've recently learned how to make my own georeferenced maps to work with it.

    There other phones that have true GPS and run Windows Mobile and so would have similar capabilities.

  7. #7
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    The phones I know that include a real GPS receiver use old GPS technology such that they suffer when there is no aGPS signal (they do this to save money on expensive GPS receivers and prevent the phone cost from skyrocketing). Some phones let you use a separate bluetooth GPS receiver. With the separate bluetooth receivers, you get better GPS hardware and better response from the phone. But not all phones are compatible with them and it would require a whole extra thread to discuss them.

    I did not have my facts incorrect about phone GPS receivers when I made the post. That doesn't mean that it won't become wrong some day. AFAIK, the Nuvifone is the ONLY one that uses modern GPS hardware for optimal signal reception and processing without aGPS. But it has other limitations...namely, it's still intended for city use.

  8. #8
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    Samsung Blackjack 2.

    Great phone and has real GPS without requiring aGPS. Nice large extended battery from factory. Windows Mobile so the software is easily found. I love my Blackjack, real rugged.
    Heck, if you cant use it as a phone with your network, It'll still work as a GPS device!
    <3 Windows Mobile.

  9. #9
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    Garmin 405 with Bike Mount

    Great review Nate. As a quick FYI -- I am super pleased with my Garmin 405 wrist-watch style GPS unit. I just started using it while biking this season (spending the last 2 years only running with the unit). I purchased a rubber bike-mount kit for $15 and have it securely fastened to the right side of my handle bars... on the edge of my grip. I can easily use my right thumb to touch the bezel on a straight away and change views/info on the face of the watch. It really is stellar!

    And, after uploading the info from watch to my computer (wireless), I kick the data into the Ascent application and can review all the specifics of my rides. Really helpful in training and comparing performances on the same single-track at different times of the year or building training workouts.

    Ascent also allows me to kick the map into Google Earth with little or no trouble, and share that image with buddies who oooo and ahhh over how high-tech I'm making an otherwise simple and raw MTB experience. It's not for everyone... but I sure do like gadgets.

    Here's an image from Google Earth as produced with my Garmin 405 and Ascent app.
    Attached Thumbnails Attached Thumbnails Looking for a GPS?-googleearth_image.jpg  


  10. #10
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    Quote Originally Posted by rke87
    Great review Nate. As a quick FYI -- I am super pleased with my Garmin 405 wrist-watch style GPS unit. I just started using it while biking this season (spending the last 2 years only running with the unit). I purchased a rubber bike-mount kit for $15 and have it securely fastened to the right side of my handle bars... on the edge of my grip. I can easily use my right thumb to touch the bezel on a straight away and change views/info on the face of the watch. It really is stellar!

    And, after uploading the info from watch to my computer (wireless), I kick the data into the Ascent application and can review all the specifics of my rides. Really helpful in training and comparing performances on the same single-track at different times of the year or building training workouts.

    Ascent also allows me to kick the map into Google Earth with little or no trouble, and share that image with buddies who oooo and ahhh over how high-tech I'm making an otherwise simple and raw MTB experience. It's not for everyone... but I sure do like gadgets.

    Here's an image from Google Earth as produced with my Garmin 405 and Ascent app.
    Nate has another review on GPS software, you should move this there.
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  11. #11
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    I am also using an LG Incite as my phone. I use a number of free programs for tracking my rides, the best of which is GPSCycleComputer. It outputs to .kmz format making it work with Google maps, which I also have on my phone. With a few tweaks gleaned from lg-incite.com (I'm a mod there) and xda-developers I now have a very good cycle computer on my phone. I still have a wireless mounted to my handlebar that I use to double-check my distances on the phone (been within .01 error over 10 miles) and to give me instant readouts since I can't see the phone while riding, but being able to upload my rides to my laptop and view the details and maps in Google maps is invaluable.

  12. #12
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    Quote Originally Posted by Miami_Son
    I am also using an LG Incite as my phone. I use a number of free programs for tracking my rides, the best of which is GPSCycleComputer. It outputs to .kmz format making it work with Google maps, which I also have on my phone. With a few tweaks gleaned from lg-incite.com (I'm a mod there) and xda-developers I now have a very good cycle computer on my phone. I still have a wireless mounted to my handlebar that I use to double-check my distances on the phone (been within .01 error over 10 miles) and to give me instant readouts since I can't see the phone while riding, but being able to upload my rides to my laptop and view the details and maps in Google maps is invaluable.
    please address software issues elsewhere. this discussion is purely about hardware. unfortunately, it seems the mods ignore this board in large part, so most informative posts here don't get stickied. I believe there's a better cell phone-oriented discussion or 10 in here somewhere, too.

  13. #13
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    Quote Originally Posted by NateHawk
    please address software issues elsewhere. this discussion is purely about hardware. unfortunately, it seems the mods ignore this board in large part, so most informative posts here don't get stickied. I believe there's a better cell phone-oriented discussion or 10 in here somewhere, too.
    Sorry, I was simply responding to a previous poster who also mentioned using an Incite, which is hardware I believe. Didn't I see you posting in this thread about Google Earth software?

  14. #14
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    Another newb here. There's so much info that I'm about overwhelmed. I'd like to buy a handle-bar mounted unit with mapping to which I can upload .gpx files. I don't care about heart rate or cadence. Any suggestions?

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    Quote Originally Posted by Sinker
    Another newb here. There's so much info that I'm about overwhelmed. I'd like to buy a handle-bar mounted unit with mapping to which I can upload .gpx files. I don't care about heart rate or cadence. Any suggestions?
    Most handheld models have handlebar mounts as accessories. There aren't many models left anymore that don't allow maps to be loaded onto them, and any GPS can do .gpx files. You're going to have to do more research to see what features actually distinguish different models before I can recommend anything.

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    Mac OSX Compatible GPS?

    I'll post this question in this thread and also in the general forum, so I apologize for the redundancy.
    I'm looking to buy a small GPS unit to mount on my bike for long distance cross country trips. I know in years past Garmin has only been compatible with PC's. Are the newer units compatible with Mac OSX? Does anyone have any recommendations?
    Thanks very much!
    redheeler

  17. #17
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    Quote Originally Posted by redheeler
    I'll post this question in this thread and also in the general forum, so I apologize for the redundancy.
    I'm looking to buy a small GPS unit to mount on my bike for long distance cross country trips. I know in years past Garmin has only been compatible with PC's. Are the newer units compatible with Mac OSX? Does anyone have any recommendations?
    Thanks very much!
    I Googled "Garmin software for Mac" and got this (About 12,600,000 results (0.16 seconds):

    We offer an entire suite of software that is compatible with Mac OS.
    http://www8.garmin.com/macosx/
    with nine programs listed.

    Garmin Forums has a Mac software forum:
    https://forums.garmin.com/forumdisplay.php?f=167

    Also:
    http://www.chimoosoft.com/products/gpsconnect/
    http://www.maps-gps-info.com/fgpfwmaclinuxunix.html
    http://www.montebellosoftware.com/
    http://www.macworld.com/article/5928...mobilemac.html

    I also sent an email to Google and asked them to make a Google version for the Mac.
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    Holy moly, slocaus! Thank you so much! You've got me off and running!
    redheeler

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    I am in the market for a GPS, I found your post very informative.

    Thanks

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    Delorme pn-40

    I got the PN-40 for kayaking and all around adventure. Works well, waterproof and fits in the pocket. Comes with free map software!

  21. #21
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    Because I haven't been able to get all the posts stickied that I wrote up, I'm going to maintain references to them in this thread that DID get stickied.

    PC Software (local machine) for working with GPS data

    GPS Data File Upload Sites

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    Presh the thread, very informative.

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    Great post Nate! Your original post was in 2009, and I was interested in if cell phone have done anything to narrow the gap between them and actual GPS units. Namely w/ Androids and Google Maps, and more specifically the Casio Gz'One Commando.

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    Quote Originally Posted by spaghettiedy View Post
    Great post Nate! Your original post was in 2009, and I was interested in if cell phone have done anything to narrow the gap between them and actual GPS units. Namely w/ Androids and Google Maps, and more specifically the Casio Gz'One Commando.
    In general, there are still significant limitations regarding battery life/recharging, GPS chip accuracy, and hardware durability. There are aftermarket "solutions" for many phones for at least some of these issues (in my opinion, something you have to get aftermarket isn't a good solution).

    I really don't keep up on specific phone models. Looking at the Casio website for the phone you mention, it appears the ruggedness issues are addressed, but the battery doesn't look like anything special and I see no details on the GPS chip, so I'll figure it is cheap and not very accurate. And, being that the phone is new, there's probably no supplemental GPS devices on the market like there are for the i-devices.

    And a side note--if that phone is intended for the US market, the product website for it is FULL of bad translations and does not inspire confidence in the product from me. Not impressed. The least the company could do is have a product website that makes sense, especially when there's such a small number of sentences.

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    Quote Originally Posted by NateHawk View Post
    In general, there are still significant limitations regarding battery life/recharging, GPS chip accuracy, and hardware durability. There are aftermarket "solutions" for many phones for at least some of these issues (in my opinion, something you have to get aftermarket isn't a good solution).

    I really don't keep up on specific phone models. Looking at the Casio website for the phone you mention, it appears the ruggedness issues are addressed, but the battery doesn't look like anything special and I see no details on the GPS chip, so I'll figure it is cheap and not very accurate. And, being that the phone is new, there's probably no supplemental GPS devices on the market like there are for the i-devices.

    And a side note--if that phone is intended for the US market, the product website for it is FULL of bad translations and does not inspire confidence in the product from me. Not impressed. The least the company could do is have a product website that makes sense, especially when there's such a small number of sentences.
    Thanks Nate!

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