What is the best - ,,landform'' for Locus.
I am using SRTM files with extension hgt ( this same as for Ozi Explorer). I don't know- my problem is becouse :
a),, SRTM '' are not full ???
b),, It is a problem with Locus ???
What i mean. It is going about ,,DYNAMICAL ATTITUDE''. All screens are from Pic du Midi di Biggore region-Pyrenees. ( but in Alps i saw the same problem)
When i tap a screen normally i see attitude like this (//http://img837.imageshack.us/img837/789/screenshot2013031414041.png) or
(//http://img43.imageshack.us/img43/4373/screenshot2013031414043.png)
But sometimes i see ,,0'' like this (//http://img18.imageshack.us/img18/789/screenshot2013031414041.png)
The text at the botton (in polish) means ,, For one point it is impossible to corectly calculate attiude''
Normally we doesn't care about this but... when we want to calculate ( or create) route and see Chart, descent and ascent of created route it can be a little problem.
See this Chart ( with holes) of calculated ( by internet) route (//http://img689.imageshack.us/img689/2346/screenshot2013031414072.png)
and what's more INFORMATION details see (//http://img841.imageshack.us/img841/9728/screenshot2013031414073.png)
Total ascent 15000 m.....???? It is a long climb (This is climb to Midi di Biggore ( Col de Tourmalet is on the road)), but of course ascent will be less then 2000m not 15000 it is impossible.
The additional 13000m is becouse of points of the road where Locus ( or SRTM) could not calculate attitude ( 53 points) (//http://img716.imageshack.us/img716/3797/screenshot2013031414063.png)
( For 53 points it was impossible to corectly calculate attitude)
I tried to see the same map in TwoNav with Europa DEM and in this same part of the map i always get ,,normal'' attitude ( no 0) like this
(//http://img29.imageshack.us/img29/4488/screenshot2013031419030.png)
I dont know where is the problem?
.
This problem also occurs in other regions, the SRTM data isn't perfect
Yes I know- I also saw many ,,holes'' in other regions - generally in high mountains ( where there are a lot of ''verticall walls'')
You think Tommy it is a problem with SRTM ? not with Locus?
Maybe converting ( i mean easilly) better DEM for ex. from TwoNav or another source is possible?
what SRTM files are you using? Downloaded by locus? Some new (from this year) or older?
Also if you provide some track with these holes, I may check places and also check SRTM files. Anyway files were all scanned! (for whole world) and should be optimized and without holes!! So you're probably using some older files or there is any issue in Locus. Track for test helps
Quote from: "menion"what SRTM files are you using? Downloaded by locus? Some new (from this year) or older?
Also if you provide some track with these holes, I may check places and also check SRTM files. Anyway files were all scanned! (for whole world) and should be optimized and without holes!! So you're probably using some older files or there is any issue in Locus. Track for test helps
I didn't update my few SRTM files downloaded via Locus for a long time. Maybe that is the reason for what I observed several times. I'll delete them and fetch fresh ones, was not aware that there was improvement.
I downloaded SRTM from this adress:
//http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Eurasia/
My training track -see enclose.
use Locus better SRTM files than this one:
http://www.viewfinderpanoramas.org/dem3.html#alps (http://www.viewfinderpanoramas.org/dem3.html#alps)
(talkingh about the 1" Resolution files)
sorry for hijacking this thread :roll:
Thanks you all very much.
I downloaded new SRTM and it it Ok.
Now i have on this same track correct attitude data without ,, holes'' .
(//http://img687.imageshack.us/img687/6884/screenshot2013031423103.png)
update of hgt files was somewhere in December if I remember correctly. We needed whole world for vector maps, so on locus server is for download complete all possible hgt files, all are highly optimized, some of them merged from several sources and non should have any hole!. Seems you confirmed this, perfect ;).
And to gynta note, Locus offer for download "only" 3' data, so if you want higher resolution, you need to download them somewhere on your own. Difference in precision was shortly tested on our side and because difference was quite small, we decided to use 3' data due to very high difference in size. Anyway it's up to you, Locus should be able to handle both
Quote from: "menion"what SRTM files are you using? Downloaded by locus? Some new (from this year) or older?
I searched but I did not find the right url :-(
My .hgt files are from 03.2012.
ok, but this means your files are downloaded by your own, not from Locus right? Then I suggest to downloaded them from locus and you'll see.
Anyway it's simple:
- hgt files from other then locus sources, may contain holes, may have problems
- hgt by locus should not have any holes and missing data! If so, send me coordinates and I'll check it
Quote from: "menion"ok, but this means your files are downloaded by your own, not from Locus right? Then I suggest to downloaded them from locus and you'll see.
I would like download your hgt files but how and where?
I tried and tried...
Perhaps I am on the free test version and I am not allowed to download from store?
they should be available in test version also. just try fill altitude to any track or points
i think he want a url...
edit
with google we will find a lot of sources
..but where are the latest and/or the most accurate?
Quote from: "gynta"i think he want a url...
Yes, of course.
I already loaded the hgt files from your link above but menion prefers his own :-)
generally there are no most accurate. every has good places and bad places. But everything is better then nothing. There is also no comparation so I'm saying this only from own experience.
And url to hgt files provided by locus do not exists. Only way is to download them directly in locus when these files are needed
Quote from: "menion"Only way is to download them directly in locus when these files are needed
I tried this too with an empty srtm directory but I got an error processing this (?) and Locus did not try to download the data.
In the meantime I walked (in a little snowstorm) 4 km over a complete plain region near our house (max. 1m height diff) and made than two screenshots:
one without fill altitude and one with offline srtm data..
I had selected heavy altitude filter during recording as always.
You can see the result is terrible.
Looks like a normal error rate.
It's not really exciting.
It's a smartphone - not an high end geographical instrument.
Quote from: "menion"...Locus offer for download "only" 3' data, so if you want higher resolution, you need to download them somewhere on your own. Difference in precision was shortly tested on our side and because difference was quite small, we decided to use 3' data due to very high difference in size. Anyway it's up to you, Locus should be able to handle both
thx and to illustrate the difference...
How are the difference in Sizes between these ''resolutions''- It is about megabytes or gigabytes ? ( i am thinking about covering FULL EUROPA)
sorry, only "ALPS" (840MB) available
http://www.viewfinderpanoramas.org/Cove ... s_org1.htm (http://www.viewfinderpanoramas.org/Coverage%20map%20viewfinderpanoramas_org1.htm)
On pictures, you compare 3' data from locus with 1' data from viewfinder right? On size of alps you may see that 1' are simply nine times bigger ... way too much to store huge areas ...
Sent from my GT-N7100 using Tapatalk 2
Quote from: "gynta"It's a smartphone - not an high end geographical instrument.
This well known of course.
But this shows that the filter should better interpolate : No real height change over 4 km and the srtm data show the same at least on some parts of the track.