CIVILIAN ACCURACY:
Each GNSS has multiple channels. In general we can say some are for civilian use, some are licensed/pay for access, and some are for military use. Basically channel L1 (GPS) and E1 (Galileo) are for free civilian use. Of these E1 is the more accurate, as good as 1 meter vs the US L1 5 meter resolution (both assuming clear line of sight and no atmospheric distortion/delay).

Earlier I mentioned system evolve. One example is the deployment of enhanced signals on US GPS channel L5 or EU’s Galileo channel E5. There are sub-channels of those too, but let’s ignore that for now. Just know that if you use GPS channel L1 and L5 at the same time the system can reduce or overcome a number of inherent inaccuracies (multi-path reflection and atmospheric delays). The same is true of Galileo’s E1 and E5 pairing.

Bottom line: The accuracy we experience IRL is improved when using multi-constellation and even more when using multi-band.

In practice Glonas is considered to have similar accuracy to GPS (slightly better at the poles, slightly worse at the equator), but is technically a 3M civilian system. I do not know of a Glonas multi-band / frequency effort similar to the US and EU efforts (again, L1/L5 and E1/E5 respectively).

BeiDou-3, like Galileo, is accurate to 1M for civilians. However, we should note Bediou-3 is two-way, and is in fact capable of reading relatively large amounts of data from your device. Certainly China has the ability to know where you’ve been, how long, and etc. Arguably such system could also side-load malware and/or render receivers inoperable. Probably more a warfare concern, but do know the US government has security reservations about BeiDou. Me too.


ASSISTED GPS / GPS-A
A cold started GNSS doesn’t know where you are and takes some time, 10-15 minutes, trying to figure out where on the planet you might be. Worse, if you lose initial satellite lock that starts all over. Net: If you’re in a poor coverage area or moving quickly (airplane speeds) you might not get a lock at all.

Earlier GPS units cached your last known location in an effort to reduce startup, but today GPS-A/A-GPS is used. GPS-A “assists” the receiver by giving it some general coordinates via the servicing cell tower location. Time to first lock is much shorter, but of course requires data service. Some chipsets require GPS-A to get a first lock and literally won’t work outside of a cell coverage area. Such a device if locked already will continue to work outside a cell coverage area, but God help you if you turn it off and then try to restart. Apple devices, at least at one time, were notorious for this.

There are “assisted” variants for many of the constellations. EG: A-GANSS is assisted Galileo.


AUGMENTATION SYSTEMS:
Just know there are other ways to increase accuracy. Typically, but not always, ground based, such exist to make GNSS services highly accurate. WAAS (Wide Area Augmentation Services) is one such that was developed to allow GPS accuracy sufficient for aircraft navigation & landings. By and large not of concern or interest to us, but you may hear about augmentation services, so now you know.


IN PRACTICE:
Since adding constellations increases performance (accuracy and lock time while under tree’s or in canyons), one certainly want’s more than just “GPS”. The informed buyer looks for a GNSS receiver that is multi-constellation aware.

A “nice to have” is “multi-band/frequency” as described above so you can read the L1-L5 pair, or the E1-E5 pair. This is touching on state of the art as of this writing though, and many won’t care.
Know that inaccuracies can stack up. GPS may be accurate to within 5M, but that’s in great conditions. You could be 50 foot off in normal use.

The right language/wording to use gets complicated in a hurry. Let’s use “Garmin Speak” as an example for one of their more advanced units:

• Use of Multiple Constellations:
  • Set “Satellite Systems” to: “Multi-GNSS”
• Enable Multiple Frequencies (e.g. L1/L5)
  • Set “Multi-Band” to: “On”

That’s the start of reasonable language for a GNSS shopping list. I suggest:

• A-GPS, GPS, Glonas, and Galileo. I’d prefer to not have BeiDou, but it will typically be included.
• This implies chipsets designed within the last few years.
• Multi-constellation capable.
• Multi-band/Multi-frequency capable.

OTHER CONSIDERATIONS:
Buying a GNSS has more than performance to consider. Some folks judge by display appearance, others are taken by features like Polaris’s Ride Command. I suggest map quality/content is the next most important consideration followed quickly by display characteristics.

 

MAPS:
Off-road use is a different thing than on-road. Personally I want layers that include public roads, but I’m also looking for DNR (or Forest Service, or etc.) marked trails, and layers that have topo (elevation) or perhaps satellite imagery. I might even want to know where various POI’s are (food, fuel, etc.). Did you notice the phrase “layers”? Ideally you want overlaying “maps” or displays that you can enable or disable (stacking each over the other) allowing you to see as much detail, but no more, than you desire. Each “display service” is known as a “layer”. An example: A pilot might like having cities, power lines, roadways, cities, and railroads displayed. Off-road? You might want to those layers off and instead turn on topography, satellite imagery, and snow/ATV trails from the DNR/Forestry service. You might even want to know where fuel is available.

Some software is pretty open and can take a wide range of map types. Many of the 3rd party applications one would run on a phone or tablet, come with their own maps and accept a variety of other maps. Dedicated devices, Garmin as an example, use a more closed mapping system and are less well suited to loading 3rd party maps (but certainly possible).

It’s also worth noting that some systems, let’s take Polaris’s Ride Command as an example, pull their maps over a cellular connection to the internet. Lose cell coverage and no more maps. Many, if you plan ahead, will allow you to download the map in advance so this isn’t a problem – the Ride Command apps included. (Note: This can take a LOT of space. Most Apple devices won’t have that kind of storage space)

No GNSS primer is complete without mentioning Bob T. Bob offers maps for most formats, free, and has incredible coverage. Search “BobT maps” and you’ll see what I mean. Man has done an awful lot for the off-road SxS community, so props to Bob T!


SOFTWARE, HARDWARE & CHIPSETS:
Hardware State of The Art:
OEM/Prebuilt systems will come with a variety of capabilities, and typically your choice is gated by cost. A DIY system is typically more bang for the buck but is best done with a little knowledge.

For phones the Google Nexus 4 and 5 phones have the best GNSS chipsets. Any Apple phone will deliver reasonable performance as well, but keep in mind GPS-A and restarts outside of cell coverage areas, as well as their limited storage expansion abilities.

The Samsung A7 10.4” tablet seems to have the best chipset (Snapdragon 662) I could find at a reasonable price (<$200), and frankly there really isn’t an attractive alternative. If you want to look deeper on your own chipsets I would look for include:

• Snapdragon 662 or even better the 855 (460,662,720, 855 all include dual-band).
• Broadcom 47755 or even better the 47765.

OEM’s, like Garmin, have their own proprietary chipsets, although I believe Sony is oft used. Apple does something similar, and it’s worth noting that they implement GNSS services in their cellular data plan (3g/4g/5g) chips. Buy an Apple device without cellular data capability and you won’t have GNSS location services. To my knowledge Apple does not have anything that is multiband.

Ideally you go with something non-Apple so you can install a large micro SD card to download maps onto.


Software & DIY Systems vs OEM:
Garmin, Magellan, Lowrance, Tom-Tom, even Polaris all make some form of factory system. There are certainly others. Trail-tech, as an example, is Poo Ride Command interoperable. Meanwhile in the DIY realm there are plenty of software options. The most common are:

1. Polaris Ride Command: (RC)
   1. It’s free, maps and all, and there are apps in the Android and Apple stores.
   2. You can easily download map regions, and make regions of whatever size you want.
   3. You can record your own ride as well, and display a few different layers.
   4. Map format is .GPX
2. Back Country Navigator, known as BCN to many was once the most popular. New apps had over-shadowed it and a new version, BCN XE was brought out 3 years ago or so.
   1. Maps are subscription based, and it’s certainly cheap enough: $15 / $20 / $30 per year.
   2. They have a pretty complete demo:
   3. I wasn’t really impressed with the map options, but you should look for yourself.
3. GAIA and Avenza are the two most powerful off-road enthusiast apps I know of.
   1. GAIA is $40 a year if you want to download maps (you do).
      1. I loaded the USFS Roads and Trails map and felt it had a lot of detail, but detail level per zoom depth varied greatly from area block to block. I didn’t care for it.
      2. Their BRMB ATV Trails looked pretty good. Good detail and consistent from area to area.
      3. I do wish the ORV trails were marked with more color & contrast.
   2. Avenza is also well respected and has a lot of maps available.
      1. Avenza has some pricing tiers. The basics are free, and there are $30/yr and $130/yr options.
      2. Some maps are free, others are fee based.
      3. I found the maps to be generally small. There are times I’d need to load 4 maps a day.
      4. Moving between maps may be completely transparent. (I don’t know)
      5. Avenza has an incredible number of YouTube training videos:
         1. https://www.youtube.com/c/AvenzaSystems/videos
         2. I suggest starting here:
4. OnX is another well regarded app, but I don’t think it's in the same league as GAIA/Avensa. YMMV.

 

WHICH APP IS BETTER?
Many will have their own preferences. For me the big gun is map detail, layers, and ease of use. When I looked at BCN XE I loaded a USFS map and was pretty underwhelmed. Really, the free Ride Command app and maps, for where I ride, were more intuitive and complete. Simple to use too. GAIA offers an on-line map viewer so you can see look over maps of the area, and I really found that useful. Just know that any map you download is really “rented”. If your annual subscription runs out the map no longer works.

Personally, I suggest starting with Ride Command (it’s free!), and learning what you do and don’t like, need, or want. I’d then look over Avenza and GAIA’s maps and see which one had the better maps of the area’s I was interested in. Either app is cheap enough it’s a non-issue. Me? I’ll likely pick up GAIA and try it against Ride Command just to see.


MOUNTING:
This is a personal preference kind of thing. Some mount to the steering wheel, others want dashboard mount, or even grab-bar mount. I prefer to mount to the top rollbar and let my roof act as a glare shield. Regardless of your preference, “Ram” Mounts are by far the most common way to mount the GNSS receiver of your choice. Don’t forget to include some form of waterproof case protector for any DIY system.


COST:
Cost is all over the place. You could start with a smart phone you have, load Ride Command, and buy a RAM mount. You’d be in for perhaps $50. A larger display via a mounted tablet is under $200. A more powerful is in the $40 area.

Meanwhile an upper end Garmin or Trail-Tech starts around $600 and you’ll still need to mount it. Still, buy a Garmin (or similar) and you might have the option of something like an integrated backup camera. Can’t do that on a DIY.


EVOLUTION:
GNSS evolution is glacial, as is adoption of advanced tech (oddly) in the GNSS receiver world. I don't see anything significant happening this decade. But tablet processor speed, storage, and display quality are constantly evolving, and that's why I lean towards a DIY approach. Others will feel differently. Still, as it sits today we can build a really powerfull receiver, get it cased up and mounted, including 128G of storage, for under $300. We can start with free software and later upgrade maps and apps for perhaps $40-maybe $60 a year in subscriptions.


HOW YOU CAN HELP:
Have you used GAIA and Avensa both? Tell us how you think they worked and what maps you've used!

 

Well written. I do think you left out a couple major options as far as software though.

1) lifetime trail maps - used to be a stand alone option like a garmin but they have moved to an app that can be added to any of the recommended devices. Personally this was the option I chose a few years ago as I wasn't up-to-speed with the details of the hardware/software compatibility as well as figuring out how to download and install BobT maps. I also made the decision that I didn't want to put in the effort like I used to to create all my own tracks and waypoints for the places I went to ride. IMO it is one of the best options for the money for those looking to simply purchase and use "out of the box". It also has great support. I once emailed, on a weekend, about a feature I had found on google maps that I thought they should look into incorporating if possible. Not only did I get a response back, it was within about 30 mins and it was the owner. Messages went back and forth for awhile that night. That kind of communication is awesome. I was just expecting a simple "thanks, we'll look into it" kind of response. Also having used it various places over the last few years, from places as large as the Windrock/TWRA to tiny places like dirty turtle and rush offroad, it has been a very accurate and useful tool. I can personally highly recomend.

2) Orux - from what I have gathered, this is where it's at if you want to dig in and go full DIY. This is the program for those looking to getting into the backend and creating their own customized solutions. Personally, I don't have the time or patience to get into this currently (hell, I barely can find free time to get out and ride). From what I have seen and read though, this software is likely the best option for those that like to dive in deep and get hands on with the technology. But, like anything else, there is going to be a large learning curve to getting into it and figuring everything out. Like learning how to draw in autocad vs. microsoft paint.

 

Thanks for the suggestions Crazy! Glad you are the second post. Think I'll leave mine as is. I'm hoping more guys with experience in other apps chime in. 'm relatively strong in the technology, but I've just not used enough of the apps. Honesly, my needs are pretty simple.

 

Very interesting ...

 

@dafish
excellent write-up as usual. concise, and on point.
i appreciate the links you post and feel that at times you can get discouraged from
others that lack curiosity to seek-out additional information, i for one enjoy the links you post.
in the spirit of the above post, no links have been added to protect the innocent and single celled beings.
to add
LeadNav (tried it. found something better. BCN)
and Dual Electronics
look-em up.

 

I like the Osmand app for Android. It is free, open source and does everything. Lots of free map backgrounds, and routing highway maps. Good track management. Too many features to describe.

https://osmand.net/

BackwoodsGPStrails.com

 

Thanks Mozart! Re dual, if you're thinking of their external GNSS receivers, did you know they aren't water proof? I used to think the 160 would be nice, but in today's world they aren't really a very complete chipset. No Beidou or Galileo either.

 

Thanks Mozart! Re dual, if you're thinking of their external GNSS receivers, did you know they aren't water proof? I used to think the 160 would be nice, but in today's world they aren't really a very complete chipset. No Beidou or Galileo either.

I as well very much enjoy reading your post. Very informative and straight forward. And at times fascinating. There are prob several others like me that read them but my not respond or reply.

So thanks for your contributions. It appears you invest a great deal of your time.


Sent from my iPhone using Tapatalk

 

I don't know what other mobile devices support L5 + E5 but the LG V60 I use for my RZR GPS does and it does seem noticably more granular.

 

Yep, that's on the Snapdragon 865. One of the two best chipsets I know of re:GNSS performance. I don't know stuffing about the phone, but it's got one heck of a chipset in it. Nice choice sir!

 

@dafish
yup. for me thats a small down side. normally i strap it around the A pillar.
i can always place it under the front hood if it starts to rain and doesnt seem to affect the data transfer between my iPad.

 

Thanks for posting this dafish, taking my time to digest and see if I want to change anything for for my own testing next week in Idaho....

 

GAIA. I use USFS Roads and Trails, USGS Topo and selective Satellite with Labels map layers. I have 10,000 sq miles downloaded easily on a iPhone 12 as topo plus less as satellite. Easy to use and mark waypoints and record tracts. When synced, everything automatically goes to my Mac, iPhone 4 and Samsung Galaxy 7a 7": maps, waypoints, routes and tracts. The maps are all free. I can invite friends to join a folder by email. I can set as edit or view only. (So they can't mess up my waypoints.) They get everything I specify including the map download. I am the map administer for Glamis North Hot Springs Resort. We use GAIA as part of our RZR rental program.

 

I am very disappointed that waypoints cannot be uploaded to Ride Command. It takes my 150 waypoints and makes them into impossible 2000 mile plus routes. Silly.

 

I upload waypoints from Gaia to Ride Command all the time. Works great.

 

I use Avenza for specialty applications in places I don't usually ride like Johnson Valley King of the Hammers. Pay to use.
Prue BLM .pdf for Big Bear and Mammoth.

 

I have used many GPS units on both Side by Side and Snowmobile. We do most of out riding in the midwest. I have been using the Garmin Zumo 595 with VV Mapping out of Michigan. VV Mapping has been the best we have found. I did pick up the new Garmin Tread, which is made specifically for side by sides, but have not played with it yet. I have Ride Command on out Pro XP 4, but I don't like how the tracks disappear from day to day.
Email: sales@vvmapping.com (or reply to this message)
Phone: 989-751-6863
Postal:
VVMapping
2555 W Pinconning Rd
Rhodes, MI 48652

 

Thanks for the kind words guys. Sorry I didn't check back sooner.

 

Too much info for me. I use the GAIA and ONX apps on my cellphone. I don't care how they work out in the boonies but they do work. That's enuf for me.

 

This is all great stuff - thanks!

 

This a great write-up. I use GAIA & ONX. I think I prefer GAIA. BUT…I use Google Earth Pro to create most of my trail maps and the upload to GAIA. GAIA makes it easy to share trails with riding partners and Google earth is a handy tool to share trail plans with the group before hand…but never use it on the trail.

I do have one thought/question. I practically burn up my phone when out on the trail. I have my Samsung Galaxy 9 on a mount on the dash of my RZR XP4 1000. After 4-5 hours my phone just shuts down due to overheating! Even if I shield it from the sun it cooks the phone.

I agree…kudos to Bob T. Thanks for all his help!!!

 

Sorry M, I'm spending less time here on the site. Your answer sir:

A phone will aggressively search for signal. This search mode is a major power suck and will in fact heat up your device. Since we download (or should) maps, the "best practice' here is to shut down cellular data and wi-fi.

The above another reason why a good tablet is preferable. No phone service to shut off, usually no data service, and a larger battery. Shut off BT and Wi-Fi and they can last a long time.

Me? I run power to my tablet and call it.

Luck to you,

-d

 

or place it in airplane mode

 

or place it in airplane mode

Yup!

Be aware it shuts off the GNSS service in some older devices. I've not seen it do that in some years, but once upon a time airlines would insist a "GPS" had to be turned off. so "airplane mode" used to disable GNSS too.

Hell, I once had a airline attendant insist I not wear my noice cancelleing headset during takeoff. And it was TSO flight approved for gods sake. Obviosly an idiot, but it still happened.

I think cooler heads have prevailed over the years though, so airplace mode likely still works. Mind you there goes GPS-A service too...

 

great write up!!! i'm just getting into gps tracking and i still have so many questions, but this is a heck of a start thank you.

 

dafish, awesome write up. Thank you for the time and research!
I have been a Garmin GPS guy for years. Still have a 60csx and love it. But it is old tech and my eyes don't work as well as they used to. Recently (3 months ago) I purchased a Garmin GPSMAP 276cx. I liked the that it was #1 a bigger screen and #2 buttons. But I am going to say now..... very disappointed in it! I used Mapsource for all my GPS work on the 60csx. The program is old and no longer supported, but for the most part does work. I decided a year or so ago to start trying to use Basecamp. I'm a simple person and found it to be a bit too complicated, so just kept using Mapsource. After buying the 276cx, i decided to try harder to understand and work with Basecamp (of course then discovered Garmin isn't supporting BC anymore either). Things were going fairly well until I discovered that BC would not install my Garmin maps (of which I purchased and own) on to the 276cx. However Mapsource would. I have worked for a solid month now to fix this to no avail! So I've just been using both programs to do what I need done, but primarily using Mapsource. Now after riding this weekend I discovered Mapsource will not offload my tracts or waypoints from the 276cx onto my PC. The last straw!!

I found your write up. I had no idea that phones/tablets could perform gps duties without data service. Last night I tested my Samsung Tab A (2016), man was I surprised! I am not a "techie", but can usually figure my way around. Since so much of this stuff seems to be going the way of "apps" and such I am considering selling off the 276cx and using my tablet (or another). 1st question I have is about my tablet. You discuss the snapdragon??? chipset. I am wondering about the chipset (Exynos 7870 octa) that is in mine. Good/bad/indifferent? Would this be a "workable" unit. Mostly I just Track my rides and save (on my PC) for later reference. I do load some "geocaching", insert waypoints of trail numbers, etc. Rarely (but occasionally) preplan routes.

Your (and others) thoughts would be greatly appreciated. Whether I will switch everything I've been doing or not..... I just don't know. But this was an awesome information starter. Thank you again!

 

Garmin Basecamp will install third party maps like BobT. You just need to go back to Version 4.6.2 Uninstal the newer version of BC and get 4.6.2 and your BC will work perfectly with 3rd party maps and google maps. Also it will keep reminding you to upgrade to newer version, just don't allow it to.

I also use use the Garmin 276cx along with Basecamp. It is IMO a superior system to tablets and mapping apps. I have a Samsung tablet running ORUX and many different maps. I use this for back at camp browsing trails and future rides. But for in the rig, and on the fly navigation, the dedicated GPS unit 276cx is better.