Suunto 9 baro very low elevation gain vs other brands

sky-runner

@markytarky said in Suunto 9 baro very low elevation gain vs other brands:

Guys, another problem is if you have a free account Strava makes adjustments, the paid account seems to just take the data.

That is completely untrue. Whether Strava makes adjustments or not depends only on two factors:

Format of uploaded data. If the data is in FIT format the data comes from the header - basically what has been reported by the watch. If the data was in GPX format there is no header, and Strava gets all the data by analyzing the track.
If the data comes from a device with barometric altimeter, Strava trusts altitude and total ascent / descent. Otherwise it ignores the elevation data and applies elevation correction algorithm that gets the data from its own database.

sky-runner

@Dimitrios-Kanellopoulos I watched my Garmin many times in real time trying to understand how it calculates total ascent. It looks like Garmin also uses 3 meter threshold, similar to Suunto. However Garmin still counts total ascent more accurately. The difference is that it uses the 3 meter threshold only initially when there is a change in vertical direction. After that the threshold seems to be smaller because I see the ascent changing in 3-5 ft increments (1-1.5 meter). Also Garmin always captures the last bit of ascent when running over top of the hill. It seems it analyzes the trend and understands that I started running downhill because it often adds the last few feet of ascent after I have already started running down.

In contrast, Suunto 9 seems to be doing some sort of averaging of altitude over 5-10 seconds in addition to the threshold, which results in additional smoothing of extremes (the lowest and the highest points). With Suunto, I noticed that I had to stop and wait at a highest point for a bit for the last 10-15 feet (3-5 meters) to be captured, and if I ran without stopping it would often miss that last bit of ascent even if I was above the threshold.

I agree that for most people it isn’t a big deal, and the whole issue is much less noticeable when moving slower, for example hiking. But I noticed it regularly enough to be bothered by it.

freeheeler

silentvoyager was heavily involved in this type of discussions and we already have plenty of these in this forum.
When I roughly compare my Fenix3 activities with my S9B activities I get the impression that Garmin exaggerates the total ascent.
I trust my S9B more than any other watch I’ve previously owned.

sky-runner

@TELE-HO I am silentvoyager. At least I was before I deleted my previous account. Anyway, I better stop here.

freeheeler

@sky-runner
welcome back, bro!

Oktan

@Dimitrios-Kanellopoulos

No, I dont know the service, but I will try to look into it.
The watch is on the bike handlebar and not on my hand.

Dimitrios Kanellopoulos

@sky-runner I understand that but there is no averaging. It’s just a time window of 3 seconds to filter out noise. Also if you use the climb suunto plus this is bypassed so it counts your rolling hills workout.

Brad_Olwin

@sky-runner said in Suunto 9 baro very low elevation gain vs other brands:

@TELE-HO I am silentvoyager. At least I was before I deleted my previous account. Anyway, I better stop here.

I think you can keep pushing on this and I agree that perhaps a better method to filter noise could work. Even though this rarely affects me because my climbs are larger it would bug me a lot. I have been asking if we could get improvements in the altitude profile graph for routes. Perhaps improvements in altitude filtering could come too. So, please don’t give up and don’t silence yourself. No watch is perfect!

Bulkan

@sky-runner said in Suunto 9 baro very low elevation gain vs other brands:

@TELE-HO I am silentvoyager. At least I was before I deleted my previous account. Anyway, I better stop here.

Welcome back!!! About the ascend debate, as @Brad_Olwin says there is always room for improvement.

cosme.costa

@sky-runner said in Suunto 9 baro very low elevation gain vs other brands:

@Dimitrios-Kanellopoulos I watched my Garmin many times in real time trying to understand how it calculates total ascent. It looks like Garmin also uses 3 meter threshold, similar to Suunto. However Garmin still counts total ascent more accurately. The difference is that it uses the 3 meter threshold only initially when there is a change in vertical direction. After that the threshold seems to be smaller because I see the ascent changing in 3-5 ft increments (1-1.5 meter). Also Garmin always captures the last bit of ascent when running over top of the hill. It seems it analyzes the trend and understands that I started running downhill because it often adds the last few feet of ascent after I have already started running down.

In contrast, Suunto 9 seems to be doing some sort of averaging of altitude over 5-10 seconds in addition to the threshold, which results in additional smoothing of extremes (the lowest and the highest points). With Suunto, I noticed that I had to stop and wait at a highest point for a bit for the last 10-15 feet (3-5 meters) to be captured, and if I ran without stopping it would often miss that last bit of ascent even if I was above the threshold.

I agree that for most people it isn’t a big deal, and the whole issue is much less noticeable when moving slower, for example hiking. But I noticed it regularly enough to be bothered by it.

Suunto is not adding altitude in increments of 3 m. I do not know the algorithm but not all ascents are multiple of 3 m, as an example: today ascent 73 m (not multiple of 3), yesterdays ascent 738 m (multiple of 3), another day 395 m (not multiple of 3). So I think that the 3 m threshold triggers the ascent counting but then the increments are calculated in another way.

Dimitrios Kanellopoulos

@cosmecosta that is correct. We dont do 3m segments.

You can climb 4m go down and that is 4m added to your ascent. You just have to “eventually” climb 3 meters in I think 3 minutes (or more) to be counted.

fazel

@Dimitrios-Kanellopoulos does this algorithm account for horizontal velocity? I have the same sense as @sky-runner - I’m more likely to see differences when cycling then when running. Thanks!

Dimitrios Kanellopoulos

@fazel yes. It does.

fazel

@Dimitrios-Kanellopoulos Thank you!

sky-runner

@cosmecosta said in Suunto 9 baro very low elevation gain vs other brands:

Suunto is not adding altitude in increments of 3 m. I do not know the algorithm but not all ascents are multiple of 3 m, as an example: today ascent 73 m (not multiple of 3),

I spent a lot of time watching altitude and ascent fields together while running up and down. I actually have both altitude and ascent fields in feet which gives more precision. 3 meters or 10 feet is the threshold. The watch can increase the ascent by more than the threshold, but I’ve never ever seen it increasing ascent by less than that. Most commonly it adds 10-13 feet at a time, but sometimes more. Yes, the actual resolution is actually less than 1 meter. For example it may add 11 feet which is 3.35 meters. Furthermore once it has increased the ascent value, that seems to be a new baseline because it doesn’t change the ascent value again unless I go at least another 10 feet up.

To give you an extreme example of how total ascent is counted, once I did tiny hill repeats because I ran in a very flat area and that was the best I could find. I did 30 repeats of 17 feet (5.2 m) each. That is about 500 ft total ascent. On the elevation graph in Movescount I could clearly see all 30 climbs and each was 17 (plus/minus 1) feet, which is clearly above the 10 feet threshold. Yet the watch had counted only about 300 ft of total ascent.

As I said, that is an extreme example, but it does demonstrate the issue.

Oktan

This issue is the only one which annoying and disturbing me in this watch

Dimitrios Kanellopoulos

@sky-runner that is what I am talking about exactly. If you climb a hill and don’t spend let’s say about 1-3 seconds (stable altitude) on the top then the last 1-3meters might not be counted. Note: Vertical speed plays a role here for this to be triggered / used.

We have several data “tests” over races and workouts to validate this ain’t a big issue.

However this is there for a specific reason, to avoid wind gusts (sudden ascents that don’t last more than 1-3seconds) , rain drops, and your arm / clothing suddenly blocking the pressure holes thus registering ascent and descent.

We don’t do stuff just because we think they should work better. We do deep analysis on data to find the middle group to both create accuracy and avoid problems that the user is facing.

Additionally those parameters are tweaked for each sport mode.

I would like not to expose more internal technology if that is ok with you. Many things have changed there since start of 2020.

The user (OP) probably doesn’t have have this specific issue I think

P.S. There is still one improvement not done and that is latch logic you had described. The reason for that is that as stated above, we cannot change something , without first having a strong RD plan / resource investment

Dimitrios Kanellopoulos

@Oktan Did you do some analysis on your claim ?

Would you like me Todo it ? Links and examples please

Oktan

@Dimitrios-Kanellopoulos I registered to Runalyze and loaded the activity there. I’m a simple user and dont undestand what to do next or how to anylize or understand the numbers there, sorry.
I attached the activity a few messages above (https://www.strava.com/activities/4486972002), so if you can test it, it would be great. If you need the gpx from Strava, I can maybe attach it here also.

BTW, I looked today at other ride, 73 km long, which I did at 2019 with Ambit 3 Peak, and the same ride this year, 2020, with S9B.
Ambit logged elevation gain of 1491 m (https://www.strava.com/activities/2101913528)
S9B logged elevation gain of 1284 m (https://www.strava.com/activities/3138457224)

Dimitrios Kanellopoulos

@Oktan can you pm me the suunto app links or fit files so I can analyse this?

I would prefer 1 activity to start with with a format like this:

FIT File or suunto app link

Expected ascent (ie what other services say)
Registered ascent