Track Statistics - Ascent under extimated?

giorgio59m Mon Jul 22, 2013 3:47 pm

I hope to be able to explain ... the issue
We use OruxMaps since a couple of years, and we're happy users. We're a group of hikers and we've or had several devices, Samsung S3, Samsung tablet 7" P1000, Samsung Note2, Samsung G70, Hauwei mobile (all with Orux installed).

We recently bought Note2 and S3, we use 2 or 3 device at the same time, during the same hike, and less or more following the same path to the top and back.

We noticed that latest version of Orux is quite "pessimist" in the statistic page, while reporting the "Total Ascent gain" (sorry for the translation, i don't know the right English word, but in Spanish is "Ganancia Altitud").

We're not checking during the last 5-6 hikes, that sometime the Altitude Gain is even lower than the Absolute Altitude Gain (Alt_MAX - Alt_MIN) which it should not be ...
I know that running these calculation there is a "filter" to detect bad points and to "clean" the errors of gps, but we suspect that the Algorithm is changed since V5 of Orux, and changed drastically, with differences up to -10 / -15% compared to other tools (OK the filter criteria can be different) but also with previous version of Orux.

I have 3 GPX files, same paths, so same starting point, same ending point.
I check the 3 files on other tools, and on Orux v5.5.2 and on Orux 4.8.4.

I tried to list in the following table the results of our investigation, and i hope you can help us to understand ....
Thanks

Note:
(*) SwissMap is a tool,only DEM data are used, so the altitude in the GPX is ignored
(**) OkMap is a tool, in my test I used the altitude from GPX



		Km	Alt Gain	Akt Lost	Alt Max	Alt Min

Giorgio P1000	SwissMap	12.4	1326	1330	2665	1562

NOTE 2	SwissMap	12.6	1373	1377	2666	1564

G70	SwissMap	12.5	1381	1368	2663	1563


Giorgio P1000	OkMap	12.34	1422	1398	2673	1563

NOTE 2	OkMap	12.79	1249	1255	2697	1574

G70	OkMap	12.5	1303	1352	2670	1561


		Km	Alt Gain	Alt Lost	Alt Max	Alt Min

Giorgio P1000	OruxMaps 5.5.2	12.38	1245	1221	2672	1563

NOTE 2	OruxMaps 5.5.2	12.5	1179	1228	2670	1561

G70	OruxMaps 5.5.2	12.68	1180	1187	1574	2697

Giorgio P1000	OruxMaps 4.8.4	12.4	1957	1933	1563	2672

NOTE 2	OruxMaps 4.8.4	12.5	1815	1864	1561	2670

G70	OruxMaps 4.8.4	12.8	1321	1328	1574	2697