GPS units

29 Jun 2015 09:33 #64408 by Riaang
Riaang replied to: GPS units
I agree with all of the above. All navigation tools are helpful but ultimately you need to look at the lie of the land and where you are going. I also use a GPS (actually, I have two, one on my arm and one in my backpack) mainly for statistical information (speed, elevation, distance travelled etc.) and to find waypoint (caves, top of passes) in areas I haven't been to before. The mre I hike the beter I become at reading the terrain, also frustrates me having to follow a track when you can actually see where to go - landed on my bum down a few mountain passes before as I was looking at the screen instead of looking where I placed my feet ;)

They have their place, as do maps, but reception can be lost or they can break and maps can blow away - do you know what to do then?

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29 Jun 2015 14:55 #64414 by Viking
Viking replied to: GPS units
I saw this article shared on the KZN Mountain Club Facebook page and I must say that I don't entirely agree with it.

I agree that blindly following a pre-loaded path can be risky both in terms of reaching your goal and getting yourself into sticky situations. This of course also depends on the quality of the gps track you are following.
Whether it is something you've drawn in on Google earth or is an actual track of high quality that someone else has uploaded and shared will make a huge difference.

I feel that a GPS is more valuable than just a statistical recording device and in my experience it is a fantastic tool to add to your arsenal. Mine paid for itself the very first time I used it, thanks of course to some accurate gps cave data from this very site.

If I am hiking in an unfamiliar area of the berg, I carry the Slingsby and the KZNW Geomap, as well as my GPS. I use the maps as my primary source of info with the GPS as a secondary source.

Would I advise relying solely on a gps? No.
Do I think you should leave it at home? Also no.

My advice is learn to use both well.

“Today is your day! Your mountain is waiting, So… get on your way!”
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29 Jun 2015 16:33 #64416 by ghaznavid
ghaznavid replied to: GPS units
I'm with Viking on this one.

You need to know the land and if you don't know where you are, the map won't help you either.

The maps aren't perfect and on more than one occasion a GPS has lead me to the roof of a cave in thick mist. You really have to know what you are doing and understand the layout of the region.

"Getting to the top is optional. Getting down is mandatory." - Ed Viesturs

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30 Jun 2015 12:34 #64422 by PeterHowells
PeterHowells replied to: GPS units
Lots of good advice above. At the end of the day you can get lost while using a map and/or a GPS - neither are magic devices to get you unlost (is that a word?) in an unfamiliar area. I find GPS's invaluable however when searching for specific spots like caves or the start of various passes.

One thing to note though is when using a GPS with built in maps, make sure that it is a topo map that is on the GPS so that you can compare the gps screen with the map you are also carrying. Using a normal SA streetmap on a Garmin unit is a waste of time in the Berg - just my 2c worth :P

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01 Jul 2015 12:29 #64440 by BobbyStanton
BobbyStanton replied to: GPS units
No one on this thread has mentioned the issue of map projections. Projecting a map is the process of representing the curved surface of the earth on a flat piece of paper. It is a mathematical transform but one doesn't need to know the exact mathmetics, only the ramifications of mixing different projections. When buying a new GPS receiver they are generally set to WGS84. In most Garmin receivers this is set under the 'Units' menu in the 'Setup' section. WGS84 (World Geodetic System 1984) is a standard for defining the shape of the earth. It is a sphereoidal model ie. is follows roughly the shape of the earth.
If you examine the current Ezemvelo maps you will see at the bottom "Gauss Conform Projection, Central Meridian 29°E, Clarke 1880 Spheroid". This means basically that a latitude and longitude from your GPS receiver (set on WGS84) will not correspond to a latitude and longitude on that map. The difference in position can be a hundred metres or more. You need to set your GPS receiver on 'Cape' to get a correspondence. Generally the receiver works internally with WGS84 coordinates and converts to other coordinate systems on the fly before displaying them on the screen. NB! All saved tracklogs and waypoints will be in WGS84, but when you display them again they will be in whatever coordinate system is set in the receiver.
The situation with the Slingsby maps is even worse. They have a grid or coordinate system called MGRS (Military Grid Reference System) which originated with the SA military many years ago. It may still be used by them for all I know. I can see the use from a rescue point of view, ie. the rescue would be carried out by military helicopters, but nowadays with the advent of GPS it is somewhat useless to mountain hikers. I have an old Garmin GPS 12 receiver which can be set to MGRS but none of the newer models have it, as far as I know. The Slingsby maps do not have any latitude/longitude marks on them so are pretty useless with a GPS receiver. They are made of a fantastic waterproof paper called Tyvek so they may have other uses when caught out in the open in bad weather.
The subject of map projections is worth knowing if you are planning any navigating, especially in other parts of the world where the maps will be different. It is not rocket science and you can probably find all you need to know in Wikipedia.
I believe that a lot of the bad remarks about GPS and its accuracy are because of an ignorance of the technicalities involved. I have never had a GPS receiver ever let me down. I always carry a map of the area and plenty of spare batteries as well.
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01 Jul 2015 13:08 #64442 by Viking
Viking replied to: GPS units
Good point BobbyStandton. The datum issue is worth noting.

“Today is your day! Your mountain is waiting, So… get on your way!”

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05 Sep 2015 20:35 #64972 by AndrewP
AndrewP replied to: GPS units
I have a perfectly good Garmin eTrex Venture HC dating back to about 2007. It has seen me through 3 GT’s, and numerous other adventures over the years. For a while now though, I have been toying with the idea of upgrading it.

So, I took a plunge and bought a Garmin GPSMAP 64s. In practise, I have had to change 3 related components:
- The PC based software MapSource is replaced by BaseCamp
- The GPS of course is different
- A Garmin Topo map is linked to a specific GPS unit so I had to get a new copy of that as well (to me, the real value of a GPS is to see the contours on your screen)

This article has is a bit lengthy, but it covers a lot of ground. For someone with an old GPS, it may give a reason to upgrade (or a reason to avoid it), and for those of you with a newer toy, this will hopefully teach you something new.

Part 1: MapSource vs BaseCamp
BaseCamp works very differently to MapSource and is going to take some time to get used to. I think in the long run that it will be a better product.
What I like:
- In MapSource, even with the display setting at the most detailed level, I had to zoom in a ridiculous amount to see the contours at a 20m interval displayed. It makes it almost impossible to plan a route entirely on the screen if you do not have a paper based map of the area to get you going. On BaseCamp, I can zoom out a lot more (700m on MapSource vs 3km on BaseCamp), and can thus see about 20 times more map on the screen and still see the 20m contour lines. Big Plus!





These 2 images show the detail I can see on my PC screen at the highest level of detail. Basecamp above and MapSource below. It is much easier to plan a route in Basecamp, well done Garmin.

- The product stores information such as waypoints, tracks and such like in a very different way. Previously, each file I had on my PC had its own definition of the waypoint for Mont-aux-Sources. Now, this is stored in a single database and a change to the waypoint is automatically picked up on any linked “files”. Tests thus far have shown that the same logic applies to the GPS itself – if you save 10 routes, each passing through Mont-aux-Sources, the summit is saved only once.
- I can now split or join routes (In MapSource, I had to either re-create the route, or delete points and re-add, which was a major headache for a route with 200 waypoints)
- you can convert a track to a route or a route to a track. I have not used this yet, but can see potential.

What I do not like:
- It will take me a few weeks to slowly convert my existing tracks, routes and waypoints from MapSource to BaseCamp. For new users, this is fine, but for someone upgrading it is a significant amount of commitment and effort. It will be worth it in the end and in this case is a necessary step in the name of progress.
- You can no longer define a default waypoint symbol. Blue Flag it is. You can change the symbol later, but any new waypoint will be a Blue Flag. Unless you edit your system registry, which I am not going to try. This may seem silly, but it is actually a feature I used to use a lot. Step backwards, Garmin.
- Routes will automatically rename anytime you edit the start/end points (this includes splitting a route). You can edit the name afterwards, but as soon as you modify the start or end, it will rename itself which gets irritating after a while. In MapSource, you had the option to turn the auto-naming off. Once again, a small thing, but once again Basecamp has gone a step backwards.


Further Comment:
Basecamp cannot talk to the eTrex and Mapsource cannot talk to the 64s. So, as long as I continue to use both GPS units (and I will), I have to move files around between the 2 packages. This is going to be a pain.

Part 2: Topo Maps 2013 Pro
I will start off by saying I really do not like the way Garmin have gone about things. For the first 2 weeks after buying the GPS and map, I had a lot of negative things to say. Eventually, I stumbled onto something useful that completely changes my mind and does actually justify the effort and cash. But, if you are used to an older model, expect a lot of uphill and dig out a list of 4 letter expletives in advance because you will want to use every one of them.

Regardless of whether you buy the map preloaded on an SD card, or download it, it will be stored on a SINGLE SD CARD and you cannot do anything with it without that card connected to your PC or GPS. So, you cannot swap out SD cards mid trip for example. Nor can you see the map on your PC without plugging in either the GPS or removing the card from it and inserting into your PC directly. (as you will see below, this is a major headache)

For now, I can get around this by using my old version of the Topo map within BaseCamp, but what is the point of buying the new map if I cannot use it in the way I want?

It takes several minutes to download the map from GPS to Basecamp. This is obviously necessary the first time and is in practise equivalent to when I first installed the older map version from CD onto my PC. But, it has happened subsequently as well, although not every time. I do not know why this is the case, but something is obviously not working right.

Once you finally get the map loaded, there are a few improvements over my older map.
- The road up to Sentinel Car Park is now routeable;
- There are 2 hiking paths (also routeable) added in the Royal Natal National Park area;
- Langibelele, Bannerman and Judges passes are included as well. I will add that the path location for each is spot on. Pity they are marked as unpaved roads.
- No other hiking paths are shown for the Drakensberg, not even the Tugela Gorge hike, which is a big pity.
- The real winner though is shown below. If you set a route between 2 random points it can generate a profile of your expected altitude gain/loss. Obviously it is picking up the height of each contour the route crosses. (this only works on my 2013 version of the topo map and is my sole reason for suggesting you use this instead of an alternative product. If this feature is not useful to you, go for something else as it will be cheaper and easier to use) One small request to Garmin would be for it to generate an expected cumulative altitude gain/loss for you in advance.



A few things are still wrong after all these years:
- Amphingati is still home to a pit 500m deep;


- The roads to the Mnweni Visitor Center are (as predicted) not updated correctly either;



Part 3: The GPS itself


Old eTrex on left and new 64s on the right.

eTrex = 104g excl batteries
64s = 173g excluding batteries


What do I get in the 64s that I did not have previously?
- I can now load the topographical maps of the whole country onto my GPS simultaneously. This compares very favourably to my old GPS where I could only load the map for 2/3 of a GT at any point in time.
- The 64s has a barometric altimeter and electronic compass. (There is also a 64 which is a cheaper model and does not have these features)
- The 64s can also communicate with a Russian based satellite system. This in theory gives you double the number of satellites to get a reading off and thus should give a more accurate reading. Tests suggest this to be true, but I would think for maximum benefit you want to be in the northern hemisphere for this.
- You can also in theory at least load other mapping files types or even a birds eye view (which I understand to be satellite images) onto your GPS, but I have not tested this out yet.
- I can load many more tracks, routes and waypoints which will be discussed later.
- I have not fully tested battery life, but for now it seems comparable to the eTrex. In both cases, the stated battery life is about 15 hours, but I regularly push my eTrex past 20 hours and the only test thus far of the 64s also went past 20 hours (on a pair of Rayovac alkaline batteries). I could of course get an extra 50% life by switching to Lithium batteries.

And, the unfortunate price for moving forwards is 10 steps back...
- The eTrex interfaced with my PC like a dream. I could connect it to the PC, turn it on and open MapSource in any sequence conceivable and it just worked. Perfect!
- The 64s is a nightmare. Do not even try to plug in the cable while the GPS is booting up, because then the GPS just freezes (in one case, it froze so badly that I actually had to take the device and map card to NavWorld for them to fix). All buttons on GPS stop working and Basecamp cannot see it. The only way out is to remove the cable. I have also found out the hard way that:
If you leave the GPS off and plug into your PC, it starts up automatically (with or without batteries in place). File Explorer windows open up so Windows can see the device and Basecamp is able to see the device. The map on the SD is available to Basecamp.
- Now, if you try to send routes, tracks or waypoints, every indication in Basecamp will be a successful transfer. The “internal storage” folder as seen within Basecamp shows the objects transferred and a little green tick appears.
- The GPS is always frozen when connected to a PC. So, pull out the cable and switch the GPS on. Wait 2 minutes for it to boot up. You will now find that no objects were transferred to the device. This is pathetic, Garmin.
- It turns out to transfer the objects you must first boot up the GPS, then plug it into the PC (remember that it will freeze if you plug in mid way through the bootup), transfer the objects, then unplug the cable (GPS is frozen until you do), then switch on and wait another 2 minutes to boot up to check. World class solution Garmin, I am proud of you.
- On my eTrex, if I tried to send too many or too large an object, I got a clear message on the GPS screen telling me the track was truncated (for example). On the 64s, because everything is frozen, you do not see this error message. So, you will think all is well when it is not, all because the only indicator you have is a little green tick in Basecamp. And, how many times do you scroll to the END of a route/track to make sure the whole object is loaded. Once again Garmin, world class design and implementation of a world class product.

Field Test
For a field test, I took both GPS devices on the VE-7 hike up Tseketseke Pass. The night before the trip, while still at home, I turned on each GPS, cleared the tracks, routes and waypoints as well as reset the odometer. I then uploaded a few points of interest relevant to the hike. I turned the GPS off for the drive down.
When I started the hike, I turned each GPS on. The 64s took double the time to boot up. I wish I had timed it, but it really was a whole lot longer than the eTrex. A few minutes into the hike I checked each screen to make sure all was working well. For the eTrex, it was: distance hiked was about 1km at a sensible speed. For the 64s, I had a complete mess. 300+km travelled thus far. It was only when I got home that I worked out the problem. The eTrex records a new track each time you switch the device on. The odometer only uses the data from tracks “while it is on”. The 64s records a single track across the turn off/on process and thus the 300km straight line distance between my house and my hike start point is considered as part of the stats for the odometer. Each to his own, but I feel this is a fundamental flaw with the 64s. Yes, I can reset the odometer immediately before I start the hike, but one day I am going to accidentally clear out saved tracks in the process and then I really will be upset. Most importantly, I go through the exercise of clearing out logs before at trip so I do not have to do it at 2am. This is definitely a case of eTrex 1, 64s 0. Lots of points lost for this.

The stats for the hike for each device are below:


I switched on each device simultaneously – the extra 2 minutes of recording time on the old Etrex shows how much quicker this is to boot up.
The difference in distance and height gain/loss will be explained below, but I believe the 64s to be the more accurate of the two.
A sample overlay of the 2 tracks in open country with good visibility of the sky is below (note the scale in bottom right, there is no real difference):


And the height against time for a similar section of the hike:


Similar comparison but this time within the pass:


Now that the view of the sky is restricted, life gets more interesting. The pass itself for the area shown was relatively straight and I did not really zig-zig to an appreciable extend. So, the straighter the line, the more accurate the measurement. The 64s is the better option.

Specs for the 64s
Tracks:
Max number of tracks: apparently 200.
Max number of points per track: 10000.
Max points per track when downloaded from PC onto GPS: The eTrex had an undocumented limit of 500 points per track if downloaded from a PC, so I tested out the 64s and managed to load a track of over 5000 points onto it successfully (I think, but please see comments about routes below)
Archiving of tracks: The manual is useless and the staff at NavWorld cannot agree between themselves as to how the storage of tracks actually works. Some people think the 10000 limit applies as a combined total across all tracks and some people think that you can have 10000 for each of your 200 tracks. After a whole lot of time on Google, I gave up and tried a simple test:

I set the GPS to record a point each second (i.e. 3600 points an hour and the limit of 10000 is reached in just under 3 hours). I also turned on the setting to auto-archive a track (also not documented very clearly in the manual or on Google). I inserted a fresh set of batteries and let it go wild. Every now and again I intentionally saved the current track (and used the default setting to clear current track afterwards). After about 75000s, the batteries died. This may make the desk in my room the most surveyed point on the planet.

I manually saved a few tracks of about 5000 – 8000 points each. The auto archived tracks always contained exactly 2700 points. Strangely the GPS waits until there are about 8000 points and then archives only 2700 of them (the oldest 2700 points get archived and removed from current track which thus retains about 5000 of the most recent points). It thus appears that you can indeed have 200 tracks of 10000 points each, but I do not have the patience to actually test this properly.

Max number of waypoints
Apparently I can load 4000 waypoints. I did manage to load over 800 waypoints without any issues so assume this limit is correct.
Max number of waypoints in a route: An undocumented limit of 250 waypoints per route that was present for my eTrex remains for the 64s. As indicated above, no warning is supplied anywhere in the process of loading from PC to GPS, so beware! Well in truth I am not sure. On the GPS itself I can definitely only see 250 waypoints in the route. But if I load it back into Basecamp, the whole route comes back. I will repeat that, to me at least, the lack of error messages for truncated routes and tracks is a serious liability to the 64s / Basecamp combo.

Conclusion:
- The upgrade has caused me a lot of grey hairs. The 64s and related software and interfacing have some serious flaws (such as lack of error reporting when downloaded routes are truncated), and the interfacing to my PC is so pathetic that in the first week I had to visit NavWorld to fix the issue.
- If you already have a GPS that works, I recommend that you do everything you can to hang onto it. An upgrade is really 10 steps back, and you do not want to do it unless absolutely necessary.
- For someone wanting a new GPS, there is unfortunately no alternative option in South Africa so you have to go the Garmin route however bumpy the road may be.
- That said, if Garmin can pull up their socks and fix a few (relatively simple) software glitches, the device will come into its own. The combined package does actually have a few really good and nifty features. Really, this is a classic case of a world class product being let down by a dozen lines of really bad code.
- For every instance where it is still possible, I will continue to use the eTrex because it is a vastly superior product as a whole. I will only use the 64s for cases where I am going on such a long run that I am exceeding its capacity (read: longer than a GT)
- Hopefully of course these are teething issues with the relatively new 64s and a future software update will correct the issues.

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06 Sep 2015 06:01 #64977 by DeonS
DeonS replied to: GPS units
I own a Etrax Vists and a GPSmap 62s and personally do not like the Basecamp setup and when using Basecamp have to export the tracks and waypoints then open in Mapsource to transfer it to my Etrax. It was suppose to make life easier.

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06 Sep 2015 10:02 #64978 by PeterHowells
PeterHowells replied to: GPS units
@AndrewP @DeonS Strange that you cannot access you older GPS using the newer Basecamp app. I am still using a very old eTrex Legend CX and when I open Basecamp the GPS is viewable under devices and I can transfer waypoints to it. In fact I can also transfer data between my Legend and my Fenix 3 watch when they are both connected simultaneously.
I am using Basecamp version 3.2.2 if that makes a difference?

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06 Sep 2015 20:38 #64981 by DeonS
DeonS replied to: GPS units
My problem is that it some will send to the etrax and some times not, will not recognise the etrax or want to transfer selected maps than have to re-boot the gps or unplug and restart. To make a long story short for me it is a quick transfer using mapsource to my etrax and even to my 62.

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