Use an altimeter to help you navigate
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- čas přidán 1. 07. 2024
- An altimeter is not strictly necessary when trekking or hill walking, but it can significantly enhance your experience and safety by simplifying and accelerating several aspects of navigation.
Benefits of Using an Altimeter
Enhanced Location Awareness:
Identifying Position: Knowing your altitude can be invaluable when traversing a long slope with minimal distinguishing features. By comparing your current altitude with your map, you can pinpoint your location more accurately.
Speed and Efficiency: An altimeter provides immediate feedback on your ascent or descent rate, allowing you to estimate how much longer your journey will take based on your progress. This can be particularly useful in planning breaks and managing your energy levels.
Navigating in Poor Visibility:
Critical Turn Points: In conditions of reduced visibility, such as fog or heavy rain, traditional visual landmarks may be obscured. An altimeter can serve as a reliable tool to ensure you make necessary directional changes at specific altitudes, avoiding dangerous terrain.
Bypassing Dangerous Terrain:
For trekkers at an intermediate skill level, an altimeter can help navigate around hazardous areas. By staying at a safe altitude, you can avoid steep cliffs, unstable ground, or other potential dangers indicated on your map.
Altimeter Techniques Based on Skill Level
Novice Technique:
Linear Features Navigation: Beginners can use an altimeter to determine their position while following a linear feature such as a river, road, or wall. By knowing your altitude, you can cross-reference with your map to confirm your location along the feature, making navigation more straightforward.
Intermediate Technique:
Terrain Avoidance: At an intermediate level, trekkers can utilize an altimeter to bypass dangerous terrain. For instance, if a map indicates that a particular hazard lies above or below a certain elevation, you can use your altimeter to ensure you remain at a safe altitude, thus avoiding the risk.
Advanced Technique:
Slope Aspect and Relocation: Experienced navigators often use altimeters to quickly relocate themselves using the slope aspect. While they may have the skills to do this without an altimeter, having one makes the process faster and more efficient. By knowing both the altitude and the direction of the slope, they can rapidly determine their precise location, even in complex or featureless terrain.
Conclusion
While not essential, an altimeter can be a highly useful tool in various trekking scenarios. It enhances situational awareness, aids in navigation through challenging conditions, and helps in avoiding dangerous areas. Whether you are a novice, intermediate, or advanced trekker, incorporating an altimeter into your toolkit can significantly improve your trekking experience and safety.
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00:11 Do you really need an Altimeter
01:53 What is an altimeter
04:13 What ate the two main types of altimeter
05:07 How does a GPS altimeter work
08:11 How does a Barometric altimeter work
09:35 How to use an altimeter
09:58 How to use a GPS altimeter
10:47 How to use a barometric altimeter
13:22 How often to reset the altimeter
14:26 Novice altimeter technique
20:25 Intermediate altimeter technique
23:41 Advanced altimeter technique
27:43 Ordnance Survey online trig point database
28:15 The test - Suunto Core altimeter vs Garmin Fenix 7 altimeter
Link to Ordnance Survey online trig point database
www.ordnancesurvey.co.uk/gps/legacy-control-information/triangulation-stations
Navigating in the area this video was filmed - at night
• Navigating in Dangerou...
Work out how much time a route will take (Naismiths Rule)
• Naismiths Rule explained
How to get round obstacles (like a heard of cows)
• Navigate in rough terr...
Barometric Altimeters are also handy for weather changes approaching, set to 0 and in the morning see if it went above or below the 0 mark. Below is an indicator of low pressure and possibly RAIN. Conversely above represents a high pressure system and plenty of clear skies.
Interesting tools indeed ! Cheers!
I like that the barometric altimeter does not depend on GPS. Reception has become spotty in some parts of the world, suffice it to say. GPS won't always be there but air pressure will.
I’m lucky to have both these watches and love both of them! I’ve had my Suunto Core for 14 years and never get tired of looking at its face. I’ve only had my Fenix 7X for a month but it’s incredible. I’m only just learning how to use it but so far its capabilities blow my mind.
Thanks for all the effort you put into your videos. I’m ex infantry and precise map reading is a necessity in all conditions and you’re a great instructor.
I also paraglide and use a dedicated leg strapped altimeter/vario (Flymaster) which is much faster/responsive at reading and displaying height changes.
I usually do not walk across country, but sometimes for me, an altimeter is very useful. I use a 12 year old casio Protrek wristwatch. One of its features is a barometric sensor and a display either in hPa or height, which eventually calculates from the air pressure, as all barometric altimeters do. At sea level, this air pressure decreases at about 1 hPa per 8 m height gain. But there is a circadian rhythm, which today changed within 16 hPa (sic!). And there is variable moisture in the air, which makes it - and thus the pressure - lighter, Hence, barometric altitudes are random numbers, if one does not have reference points again and again, especially if the walk extends over hours. I find it tedious to always recalibrate my altimeter. I just memorize, how much I am wrong at a known point, and subtract or add the difference.
It's great for the Scottish Munros when the chance of a cloud free summit is low, it's a long ridge with lots of false tops, and the kids (and other 'followers') keep asking "Are we nearly there yet" after each and every steep rise!
Also great for knowing when to expect to reach cols, or traverse past problem terrain.
Enjoyed the video very much. One way I've used altimeters is to follow a contour line, say, 530 meters until I achieve a specific compass heading then use that as an attack point.
Again, great video and instruction!
Cheers
Another excellent video.
You explain things that I have been struggling to understand in a way that simplifies them & makes sense to me.
Thank you .
Interesting and more uncommon topic. Thank you for makng this video
I 'look after' a handful of OS benchmarks in my home area. A neat infill of yellow paint keeps them visible and hopefully less likely to get interfered with. There is some nostalgia in my motivation but mainly they are to provide a handy local reference for calibrating portable barometers /(altimeter) to QNH.
The paint makes a difference , our yellow crowsfeet have apparently featured on a local interest Facebook site.
(An Irish boatman).
I’ve been following your channel for a while, I really enjoy your channel and content, love seeing the country side across the pond, looks awesome, also, I have learned so much with your tutorials, I’ve applied the knowledge, it’s an awesome feeling knowing that I haven’t got lost, yet! 🤣. Thank you so much for sharing your knowledge. From Washington state, USA. 👍🏽👍🏽👍🏽🇺🇸🇺🇸🇺🇸❤️👊🏿
Thanks for your kind words.
In mountaineering we use them quite a lot, for example when navigating a cliff face we use them to find the start point of the climb/route, where bivi spots are etc, also for checking you are at the correct summit point when at the summit (when there’s no trig point) the gps ones are way better for accuracy when using them for mountaineering as the whole air pressure thing becomes a lot more noticeable when your hanging around and not moving at belays.
Garmin Fenix watches uses barometric altimeters, calibration of it can be done manually, using GPS altimetry or GPS with digital terain model.
Id never even thought about using my watch that way, I guess I rely on other forms of measure and havent kept up with the times. Its another useful tool for my toolkit, thanks for making this video and sharing your always impressive knowledge!
Sounds like I hav to tell my altimeter my altitude more than I need it to tell me.
Welcome back buddy, I missed your company. 2 very important questions:
1: what kind of tea are you drinking?
2: do you brew the tea first and then put it in the thermos or (3) just put hot water in the thermos?
Waffling on here with another, do you have a brown Betty?
I just picked one up here in the PNW at a thrift shop for $12. I'm really getting into this tea thing as a former espresso guy. I'm drinking PG Tips and just recently got turned onto a Chinese black tea. Gimme a PO box or something and I'll send you some to try in return for all of the education you,ve contributed to my existence!
Later, dude.
Okay then, one more... Milk? Sugar?
PG Tips ???? Not sure many people (other than tourists) drink that anymore. Yorkshire Tea bags are the way forward.
If you get the ones with the string you can make tea in the flask, which keeps it hotter, longer.
Oh and I know folk used to put the milk in first - so the boiling water didn't crack the thin porcelain cups, but cups (and flasks) are more rugged now - I put the milk in after.
50 years ago my survey boss had a barometer/altimeter in a big wooden box that we’d calibrate at post office elevation markers. I think it read to ten feet increments and it worked great for figuring out where you were in the mountains if you had a good topo map.
Interesting.
I've found that a barometric altimeter is only reliable if the weather is settled. If a low pressure system is close by then the pressure will fall or rise significantly over a few hours. I've had my Suunto Core watch read 30m different at the end of of a run / walk than it did at the start, despite me being back at the same place! Yes you can recalibrate it at known heights during your walk but it's a bit of a faff.
A good experiment is to set it for the known elevation of your home and leave it in situ on your desk etc for several hours and see if it thinks you have gone up or down in elevation.
Also some GPS watches are more accurate than others. My Coros Apex Pro watch seems to be more reliable than my Garmin Fenix.
Thx a lot Sir, I learned something new today....as I usually do when I watch your videos :) Wish I could join your nav courses. Greetings from Copenhagen.
What do you think of the thommmen altimeter bit old school i know but not reliant on batteries.
I saw someone using one a few years ago but I've never had one so I can't offer any comment. But they do look fun.
👍👍
"Goodness is that the time?"
"No, it's a barometer."
"In that case it's high pressure I was off"
Two Ronnies c1970's
I've been following your channel for some time now and. I love your presentation and quality. The "waffle" bits are marvelous. Keep up the good work.
P.S Do you run any nav courses in the Lake District?
The Lake District is (maybe) the only part of England that I don't run public courses. I do run many private sessions there though.
If using the OS Locate app (and potentially others) on your mobile phone, be aware that the GPS reference ellipsoid zero height does not match the UK sea level at Newlyn with a height difference of 55m, so somewhere in the processing that 55m GPS to sea level difference has to be compensated for. Certainly on my mobile phone it's either done twice, or never, and when I look at the GPS indicated heights they are 55m 'wrong'. Different systems make different 'mistakes'. Always check your own readings.
Got an ABC watch and I should use these features more offen, GPS has made me very lazy. Thanks for sharing your knowledge ❤.
Can you make a video on strategies for Micro navigation in bad weather when there are very few collecting/catching features, handrails, visible references
Many weather apps will give you the current barometric pressure for an area. So, you can enter that into your barometric altimeter before you start your walk. Also, you don't need to spend £££ on a dedicated altimeter as there are many phone apps that will give your GPS altitude and many smart phones can measure barometric pressure.
Hi, love your videos.
Can I just correct a small mistake?
At 4.30 you make the very common mistake of saying satellite navigation can triangulate your position. In fact it's known as trilateration as positioning is done by the difference in time of the arrival of the different satellite signals. As you will know triangulation is the fixing of your position by taking angles. Even a major satnav (GPS) manufacturer once printed this mistake in their brochures so you're not alone.
Two satellites give a position, three will give altitude as well.
👍
Hi - Thanks for the video - A quick Q - As the Fenix also has a barometer - did you have it disabled?
Yes. I was using it in GPS mode only.
I'd be interested to know what you think of the "analogue" altimeters on Amazon made by the Sun company. Thank you for the video!
They seem a bit pointless to me - just my opinion so others may disagree, or I may be just wrong. The theory is that you have to continually take information from a map (which means you don’t need an altimeter in the first place ) and set the height it on the altimeter. But, as it’s graduated in 100ft units, in reality you’ll only ever be able to use a contour line to do this. Being able to find your position on a contour line is something I only ever teach on advanced courses, and to be honest if you can navigate to that standard you don’t really need an altimeter - but as I said in the video they do sometimes make things quicker to do.
Would being under a fleece sleeve or waterproof coat affect the accuracy of the barometric altimeter - ?
That's a good point - I don't know the answer, but maybe body heat would increase the air pressure.
@@TheMapReadingCompany As long as the Altimeter is not in a completely airtight enclosure, I find it hard to believe that it affects much. Especially not when the smallest unit of measurement is a meter.
2:10 Altimeter, not GPS ;-)
Oh - I didn't notice that, well spotted.
@@TheMapReadingCompany no problem. Very good content btw, always something new to learn 👍