Altitude Readings - GPS or Altimeter (barometer) ?

[ol' boy]

I hope i'm not confusing the Samsung Note 8, with the old Samsung Note 8" GT-N5510 (which i have)
I probably didn't make that clear, but i think i had the correct link above?

This is what i have:

[Thala Dan]

Well........speak of the devil:

Man, 10-year-old daughter missing in snow at Thredbo after being separated from snowboards

NSW Police say they are coordinating a search for a man and his 10-year-old daughter believed to have gone missing in deep snow at Thredbo.

A spokesperson said the pair had been separated from their snowboards and the group that they were with and officers are working to coordinate a search.

NSW Ambulance confirmed they had received a call from the man at 2:55pm on Monday afternoon.

A spokesperson said two vehicles had been deployed to scene, and that the pair were believed lost in "deep but lightly packed snow".

He said rescue workers believed the man's phone was running low on battery.

A spokesman for Thredbo resort said the pair were believed to have been snowboarding in back country outside the resort's boundaries.

More to come.

[Jma]

Using GPS's quite a bit over the years I believe they give more consistent elevation data than barometric elevation devices.
Comparing to paper maps or trig points etc., usually the GPS is accurate to within a metre or two, whereas the barometric devices can be out many times that amount.
Seems there's a few factors that can affect the barometric devices, from my own experiences temperature seems to be a factor, air pressure changes with approaching storms etc. can be another.
I have a Garmin Instinct watch that has the option of barometric elevation or the use of GPS to calculate the elevation.
The GPS calculated elevation is far more accurate and consistent than the barometric's readings over the same areas.
If I manually calibrate it before heading out for the day it seems to stay pretty consistent for the rest of that day, but I notice if I calibrate it one day in a certain spot at say 270 metres, then don't calibrate it for a few days, next time I'm in the same spot it might show a difference of anywhere up to 70 or more metres from the previous reading.

The OziExplorer linked to above is for the PC version, used for planning trips, saving tracks, waypoints, creating maps & all sorts of other stuff.
There's an and a of the navigation software available that work on many GPS capable devices.
You can also use the PC version with a laptop as a navigator by using a USB GPS antenna if so desired.
I've never used the PC or android version for navigation but have used often the Windows CE version on many different GPS's, Navig8r, Navman, Chinese fleabay devices etc. etc.
There is Screen Designer software available for both & devices, you can design your own screens or modify the included screens on the PC then put them on the device/s for your own use.
On those screens you can add all sorts of parameters, altitude, speed, date, time, odometers, trip info, compass and many others.

[eeprommemory]

I hope you not confusing my Samsung Note 8, with the old Samsung Note 8" n5510
I probably didn't make that clear, but i think i had the correct link above.

This is what i have:

yea no barometer in that one but has IRblaster /ir godstick great for changing channels on tv at pub.

[ol' boy]

yea no barometer in that one but has IRblaster /ir godstick great for changing channels on tv at pub.

So does the Redmi Note 4, have you seen me in action, i often get in trouble at Pubs and Bars
Especially when you go in the input menu


I saw that story in the news to Thala and though the same thing!
Years ago in South Island, NZ. We tried using GPS Altitude to mark way points on ski resort access roads.
Then we would ride the back country and check our altitude to see we were still higher than the access road and hadn't gone lower, and could still meet our road side destination without having to climb back up through the fresh snow.

Outcome, we were 2 valleys over and completely screwed up

[eeprommemory]

i turn on the subtitles and change the channels.

[Thala Dan]

i turn on the subtitles and change the channels.

You've both been very, very naughty boys

[ol' boy]

You've both been very, very naughty boys

What?..... ;-)

[eeprommemory]

why did you block out the love hotel.

[ol' boy]

Side by side testing

Redmi Note 4 vs Samsung Note 8"
GPS only Altitude findings...


My Home


Redmi


Samsung




Sea Level (At the beach, next to water)
Multiple readings taken, with a range of 20meters!
(Both units moved range at the same time, even though both units were never moved, obviously as the GPS sats move???)

Redmi


Samsung


Redmi


Samsung



Back at Home

Redmi


Samsung


Conclusion:

Both units seemed to roughly concur for a given Time and Place!
Time being a very important observation.
When one unit was reading High, so was the other unit. And vice versa for the same given location.

Sea Level, well what is Sea Level?
Tides here are 1 meter, Tides in Darwin are 12 meters.
I had both units placed at about half tide, on the sand and facing north.

As for 1 meter accuracy?? Not that i can tell
Accurate to with in 10meters maybe.

Probably good enough for my needs, but i'd still be interested in a handheld unit that did not flounder around so much
But i am not paying $400 for a proper unit.

Note: When i first used the Samsung at home, its said i was 96M high and when i lowered the unit to my feet from holding chest height, it said 95M.
I thought i was on a real winner.... Then the different readings started.

I suspect the SUNROAD eBay unit probably isn't much better, but who knows?

All in all, this brings me back to my opening post.... What is better? GPS or Altimeter?

[ol' boy]

Interesting read, as you say eeprommemory, the barometer chip in the S5 is helpful

Global Positioning System (GPS) receivers can also determine altitude by trilateration with four or more satellites. In aircraft, altitude determined using autonomous GPS is not reliable enough to supersede the pressure altimeter without using some method of augmentation.[8] In hiking and climbing, it is common to find that the altitude measured by GPS is off by as much as 400 feet (120 metres) depending on satellite orientation.[9]

[Jma]

All in all, this brings me back to my opening post.... What is better? GPS or Altimeter?

How long's a piece of string?
GPS is better in my opinion, others will prefer an Altimeter.
My experiences with both I find the GPS is more accurate more often & doesn't require constant calibrating to get consistent accurate readings.

[eeprommemory]

try and find a gps drift map apk it will give you some idea of whats going on.
i have a 15 year old Marconi gps L1 L2 i did not have the software for it so i emailed them the guy sent me the monitor and config software it had a drift map built into it and gps messages and warnings then the guy clicked and then wanted my serial and firmware ver that was the end of email contact with him.
it had a neat gps message window in binary mode that let you know when NOT to trust it.
it said some real interesting things during the war.

[ol' boy]

The irony in all this, is Sea Level....

The local Mountain i'm interested in, holds a datum point by which a mean sea level monitor is calibrated off at my local pier (12km away)
The Sea Level monitor is owned and run by the University of Adelaide as a "Global Warming" exercise, it has been there for 25 years.

When it was installed, i was told they can measure to the sub millimetre if the Pier (and the Equipment bolted to it) had moved up or down
I have no idea how they do this.....

But i really didn't think it was going to be so hard to get an accurate Altitude measurement
By the sounds, i need a very accurate Barometer, calibrated it at Sea Level, then drive straight up the Mountain i'm interested with in the hour on a stable barometric weather pattern day.


I think what i am learning here, is "Meters above Sea Level" is more symbolic than actual

[eeprommemory]

The irony in all this, is Sea Level....

The local Mountain i'm interested in, holds a datum point by which a mean sea level monitor is calibrated off at my local pier (12km away)
The Sea Level monitor is owned and run by the University of Adelaide as a "Global Warming" exercise, it has been there for 25 years.

When it was installed, i was told they can measure to the sub millimetre if the Pier (and the Equipment bolted to it) had moved up or down
I have no idea how they do this.....

But i really didn't think it was going to be so hard to get an accurate Altitude measurement
By the sounds, i need a very accurate Barometer, calibrated it at Sea Level, then drive straight up the Mountain i'm interested with in the hour on a stable barometric weather pattern day.


I think what i am learning here, is "Meters above Sea Level" is more symbolic than actual

in a temperature controlled box or its pointless.

[ol' boy]

Its official, i just fried my brain!

[Uncle Fester]

... Of course not every phone has a pressure sensor.

Turns out I do have one on my now ancient Huawei Mate 10.

Of course all the bloody altimeter apps want you to connect to the Internet to "calibrate", more like collecting your data, hammer you with ads, whatever.

However finally I found a proper one that I can calibrate manually, something I can use not only to find the elevation in a hotel room but in the actual bush away from the Internet

or just the APK:


And blimey, if you set it to ft it detects me standing up and sitting down on a chair, it is that accurate. Love it.


Sitting:


Standing:


That was manually calibrated to sea level, which I know.

Lets do relative, calibrate sitting in chair to zero feet:


stand up:



This is crazy, I could do this all evening, LOL

Damn, I have to pick someone up from the train station. Better not bring this in the car, major distraction!

[eeprommemory]

Turns out I do have one on my now ancient Huawei Mate 10.

Of course all the bloody altimeter apps want you to connect to the Internet to "calibrate", more like collecting your data, hammer you with ads, whatever.

However finally I found a proper one that I can calibrate manually, something I can use not only to find the elevation in a hotel room but in the actual bush away from the Internet

or just the APK:


And blimey, if you set it to ft it detects me standing up and sitting down on a chair, it is that accurate. Love it.


Sitting:


Standing:


That was manually calibrated to sea level, which I know.

Lets do relative, calibrate sitting in chair to zero feet:


stand up:



This is crazy, I could do this all evening, LOL

Damn, I have to pick someone up from the train station. Better not bring this in the car, major distraction!

Altimeter



no advertisement no in app purchase only 1 permission (gps)
if it has advertisement and or in app purchase it does NOT get installed apps stealing you login data credit card info paypal logins is not funny.
i got done by a IRblaster apk i backed up the apk and looked at the files and it had everything it is FREE for a reason.

[Thala Dan]

[B]I suspect the SUNROAD eBay unit probably isn't much better, but who knows?

I'm afraid your suspicions might be closer to the mark than you'd like.....here's one bloke who has done a bit of on-the-ground testing (Amazon UK reviews):

Delivered on Sunday and used on a Munro walk on Tuesday. The main reason for buying it was to have an easy-to-access and easy-to-read altimeter, simpler than digging one's phone out of a pocket, or pulling a sleeve back to read a smart watch. Setting up the device was straightforward and it was simple to skip the unnecessary functions. Compass, Barometer, Altimeter, Back Light and the LED "torch" are easy to access; perhaps a little too accessible as when putting the device into a pocket, say, you can accidentally change from one function to another. The LED torch is inadequate in a dark room, for example, but it is enough to read a map in darkness. Having set the altimeter while sitting on a contour at 100m, it was then approx 30m off (low) when standing by a cairn at 944m. You need to check the barometric pressure setting a couple of times before putting too much trust in the altimeter. The cord attaches easily to a carabiner and, having been snagged a couple of times when taking the rucksack off, the cord has more than enough strength. The compass seems reasonably accurate but it's not like the Silva and is best used just as a quick check rather than for precise navigation in poor visibility. It's early days but so far so good.

19th March. During another hill walk, the altimeter function was 40 to 60m out. Another check was to compare the altitude at the start point before the hike and after; the two readings were significantly different. Also, the compass bearing wandered considerably. The supplier, Sunroad, was very helpful although they maintained that the device is inherently accurate which is not my experience. Sunroad recently brought out a GPS version so I’ve returned the FR500 and ordered the FR510. The 510 uses the Beidou GPS satellites which have recently been extended to provide global coverage.

I've got two handheld GPS units - eTrex 10 and Oregon 600 - the eTrex is GPS altitude, and the Oregon is barometric.

Took them out onto the verandah just on dark and stayed out until I could no longer feel various parts of my anatomy.

The readings on both units moved around a little, but stayed within several meters of each other....it was too damned cold to take notes, so....I'll set them up outside tomorrow and leave them on for a while and take a few readings/photos and post later on.

Of course, none of this answers the question "How good is a $30 unit on eBay".........but I don't think the outlook is real good in that department.

Incidentally, OB, my US$20 offer received a US$22 counter-offer......he offered me a whole US$0.99 off! You wonder why they even bother with "Make an offer" on their listing.

Think I'll hang on a bit and follow this discussion further for a while.

Good to see they found that bloke and his kid at Thredbo....still reckon a PLB should be mandatory for that sort of activity........dammit, I carry one with me when I go wading up trout streams!

[eeprommemory]

Good to see they found that bloke and his kid at Thredbo....still reckon a PLB should be mandatory for that sort of activity........dammit, I carry one with me when I go wading up trout streams!

i carry one of those power bank phone chargers when i go roaming can charge 2 phones up to 8 times has inbuilt torch.