Thursday, 14 July 2011

On GPS Part II: Garmin Foretrex 401 Initial Analysis

So, for reasons I have already discussed, I wanted a lightweight, basic, easily accessible GPS system. BPL forums again assisted in this regard and after some surfing and comparison I whittled the nominees down until the winner was decided upon - the Garmin Foretrex 401. At 87g with wrist-strap and two NiMH rechargeable AAA batteries, it is on the face of it exactly what I was looking for. The fact the batteries are AAA, the same as those used in my XP2 headtorch, makes perfect sense and was a feature in my decision - it means I can take 4-6 replacement batteries (12g each) on a long trip and multi-task them. As I did recently with my Suunto Vector, I can secure the 401 to it the sternum strap of the Gorilla/Villain an have ready access to it.




So, what do I think of it? First off, I am pleased with the feel of the unit. It is durable, waterproof to IPX7 (meaning it is protected against water immersion - Immersion for 30 minutes at a depth of 1 meterand compact. The buttons are easily accessible and the screen is easy to read. It is simple and functional. The wrist-strap is a rugged velcro attachment which is perhaps a bit more rugged than it needs to be and could be a little slimmer, but I think my view on that is more as a consequence of where I intend to attach the Foretrex 401 to my person rather than any real criticism. I have strapped it to my wrist and it sits snugly and securely and, relatively, comfortably. This is no Patek Phillipe timepiece to adorn your wrist, however, and it feels a touch bulky and cumbersome there so I am content to attach it it to the sternum strap of my rucksack. Remember, though, this is a feature-rich GPS given its size so place this criticism into context.




What can it do? The Owners Manual can be found here and I suggest you have a read of it along with this Initial Analysis to see exactly what the 401 can do. It's simple enough, direct and mercifully short. In summary, the 401 has in-built altimeter, barometer, electronic compass and timer along with the standard GPS functionality. Calibration is much the same as most of these devices - calibrating the compass requires holding the 401 level and turning on the spot very slowly (it tells you if you are going at the right speed) for two full turns - the compass is then calibrated. As I said, this is much the same as the Suunto Vector's compass. There is wireless transfer to other devices capable of the same, as well as the potential for a USB hook-up to a Mac or (heaven forbid) PC.


Acquiring GPS satellites, outdoors on a clear day, took just short of 4 seconds. Now, I can tell you - that is pretty damned fast. In the real world, I doubt that is going to be beaten or, if it is, it really won't matter. I know the exact elevation of my back patio and top level of my garden - 120m - and the 401 resolved that without calibration, but you can manually enter elevation if you know it. I often do this with the Suunto Vector if I am at a point where the elevation is beyond doubt as it improves accuracy. 




All of the information needed to operate the Foretrex is found on the five main pages: the map page, the compass page, the elevation page, the trip computer page, and the main menu. Jumping from page to page is done by using the (shock, horror) 'page' button. Scrolling up and down within in each page is done using the up and down arrows and selecting an individual item is done using the 'enter' button. This is not a system intended for nuclear physicists. Pressing the 'page' button quickly will ignite the orange backlight. Doing so again will turn it off.


The Map Page displays the distance to your next waypoint as well as bearing - this is the primary navigation page of the unit. The Compass Page is obviously self-explanatory but also displays distance to final destination and speed. The elevation page, apart from showing current elevation, shows a graphical representation of the route profile with the distance covered, or time spent, beneath it. I deal with the Trip Computer page below. The Main Menu controls your waypoints, tracks, routes, unit setup, connectivity and GPS settings.




The Trip Computer is the reason I bought this system. I don't need the mapping - if I did I would have looked at the Montana - but I do want to be able to program waypoints/routes and have a log of distance, speed, ascent and descent as well as being able to plot my travelled route on a map at a later date, at home, over a cup of tea and a hot, buttered scone. The 401 can do all of this as through its trip computer. In fact, the list of Data Field Options is comprehensive - listing them all here would be tantamount to a cure for insomnia (read pages 15 to 19 of the manual if you really cannot sleep tonight) but the highlights include Ambient Pressure/Barometer, Average Ascent/Descent, Total Ascent/Descent, Max Ascent/Descent, Max Elevation, Bearing/Course, Distance to Final Destination, Final ETA, Sunrise/Sunset, Speed, Odometer and Off Course (which measures how far off course you are). There are more but those are the ones grabbing my attention at present. Sadly though, and this is the only flaw I can see so far, you can only display five at any one time - the unit can be set to change those five, but that's a bit time-consuming - it would be easier to have more than those five easily accessible. As can be observed in the image above, the USB connection is USB 2.0 to USB Micro-B as on most standard USB mobile devices. The cable comes with it, but anyone with a BlackBerry or digital camera will recognise this connection. So you can connect the 401 to your Mac/PC and add waypoints, tracks and routes through .gpx files.




I downloaded Garmin Basecamp to permit me to export Anquet .gpx files to the 401. It is relatively straightforward - open Basecamp and select IMPORT from the File Menu. Find your Anquet saved Database and select it. Basecamp imports it. Then you can connect your 401, and click the icon SEND LIST TO DEVICE. It will ask what you want to send it as - a route, track or waypoint and there you go - it will appear in the ROUTES folder, or whichever folder you have selected. It's that easy. I can then import a track, which is a record of where I have actually walked with the device on, and it will tell me all sorts of interesting information such as distance, speed, elevation, ascent/descent and so on. I like it.


I will add on a later Debrief post (probably when we do the Nantlle Ridge in later this month) how the 401 does, but specifically, what the battery life is like. However, I reproduce this part of the manual for your ease of reference as this is likely to be crucial for those buying the 401 - their reasons for buying a unit like this will almost certainly include extending battery life beyond that of other units and over the iPhone and other mobile telecommunications devices with GPS included. On battery life, I will conclude with these points from the manual - good unit this and I am looking forward to using it.


"Optimizing Battery Life

Use premium batteries for optimal performance and maximum battery life. Consider the following suggestions to maximize battery life:

Excessive use of the backlight will significantly decrease battery life.
Select a shorter backlight timeout (page 3 of Manual).
Turn tones off if not needed. From the main menu, select SETUP; SYSTEM; BEEPER; OFF.
Turn off the compass when it is not being used (Foretrex 401 only). Select SETUP; HEADING; COMPASS; OFF."

An Update
I just went for a 6km run this morning (16/7/11) with the 401. It was cloudy and it took 28 seconds to acquire a GPS signal. Compare this to 4 seconds on a sunny, clear day. A point to make is that if the unit does not get the elevation right initially, your data will be inaccurate throughout as it changes the elevation. Try to calibrate it before you move off if this is important to you (as it is to me). Further, downloading the 'Track' to Basecamp might mean that it becomes saved as two Tracks or 'Active Logs'. You can select both and join them together via EDIT; JOIN TRACKS. It will ask which you want first and then you simply select OK. Other than that, you'll have a raft of useful data, including distance, area, elapsed time, ascent, descent and average speed, with which to spend countless evenings indoors, while the rain batters your windows, comforted by a mug of steaming tea and the Euclidean formulae to be constructed from it. It will also plot the Track on a map with co-ordinates so you can see where you have been. I don't have a electronic map of my home, so I cannot tell you if I can import this into Anquet or whether I'll have to manually plot each waypoint but I'll know better when I get back from the Nantlle Ridge on Wednesday because that I do have electronically. Either way, if you have gone off course, for example, finding out how would be easy. In terms of physical operation, the wind and rain battered it, but it was easy to read on the move, easy to adjust and easy to operate. It's simple, effective and functional. Good stuff, Garmin.

9 comments:

  1. Nice to see you use the 401 for trip data. I use the Forerunner 310Xt for this purpose. The only problem on long trips is that the battery has to be recharge. It can't be replaced by AAA's.
    Battary repacement is defenitly a reason to use the 401.

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  2. Battery replacement was the primary reason I purchased a unit separate to my iPhone but as I considered it more closely, I realised that avoiding getting my iPhone wet meant I often kept it in my rucksack and did not look at it frequently. With those two in mind, I wanted a small unit I could examine often.

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  3. Have you had much use of the barometer, does it need continual calibration or does it sort it's self out?

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  4. I have not yet used it. If you download the manual it will you there.

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  5. How do I keep the altimeter correct.  I have to re-calibrate every day.

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  6. I found atmospheric pressure affected it from time to time but I tended to recalibrate every day as we stayed in huts so I knew the exact altitude.

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  7. Great review, thanks. Can it operate strictly off USB power?

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  8. Not AFAIK, plugging in USB power will switch it to PC connectionmode and voids the waterproof ability. I am more concerned with the durability over time. As it ages, they lose their waterproofness! My F401 was waterlogged when I was dunked into fast shallow when my raft overturned during wahite water rafting. And the USB cover-gasket broke after repeated opening & closing. Now I consider my Foretrex as non-water proof - just barely water resistant (I would not expose them to anything more dangerous than light drizzle!) Kind of sucks as you need them the most when weather is bad!

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