gnss capable celular con buen accuraccy

Started by UH1169, May 21, 2020, 09:03:30 AM

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UH1169

hello out there, since many years i am a kind of power user of orux maps. i use it for hiking and trailrunning in the mountains. i want to use a new phone and up to now was not able to find a suitable replacement for my old 2011 motorola defy plus 4 inch 120grams when it comes to recorded gps track accuracy. i spent large amounts of time trying out 2 new handies, analyzed different settings etc. but both had (different) problems. my last try was the cubot kingkong mini outdoor phone (4inch!). but its accuracy and stability of receive/hold the gps fix/position is poor. in spite of an displayed accuracy of 2-4meters in GPSStatus app the recorded track is not accurate, often 40m apart from the followed route then comes back again to be exact. often in spite of 2m accuracy the position still is somewhere and does not come back to the current location even when standing still for minutes.

i would be pleased if you share your phone which you use sucessful with orux.
my key requirements are small, light and robust gps signal processing even when the fone sits in an outer pocket on the chest, in a vertical orientation. i suspect some phones have a weak signal when they are not oriented horizontal (hold in hand) and when it sits near to the body so that some of the satelites are blocked.

thanks in advance

UPDATE/Answer:

inshort: see here which device offers "good" gpss capabilities:  https://developer.android.com/guide/topics/sensors/gnss   (but it does not reflect antenna related restrictions)

scroll down, table for a list of dual frequency gnss capable devices: https://medium.com/@sjbarbeau/tl-dr-dual-frequency-gnss-on-android-table-of-devices-9be4bbb83a7b
( https://medium.com/@sjbarbeau/dual-frequency-gnss-on-android-devices-152b8826e1c )

https://www.researchgate.net/publication/340392820_GNSS_code_and_carrier_phase_observations_of_a_Huawei_P30_smartphone_quality_assessment_and_centimeter-accurate_positioning





lneam

hi user UH1169,

i read your post. Please don't expect from me an answer like "buy this model ...". i will give some solutions, that i will be very happy if i could have them into my personal collection. The model price or size, or ... it's relevant. of cource all of them is a good outdoor navigation solution for the year 2020 compared to PND old hardware. There is no need to install a sim card to work the device. and of cource it's my personal opinion

1. Samsung Galaxy XCover 4s
review link
https://www.notebookcheck.net/Rugged-Smartphone-Samsung-Galaxy-XCover-4s-in-Review-A-Rarity-for-Outdoor-Smartphone-Fans.428745.0.html
" read the gps section inside the oreview"

2. Land Rover Explore
see the video
https://www.youtube.com/watch?v=EjELl7kP8uM

3. carpe iter pad
https://carpe-iter.com

4. Trimble TDC600 or Spectra Precision MobileMapper 60

Franchu

Hola.

Yo utilizo mi Samsung S8 y estoy muy contento. En bici, lo llevo sobre el manillar y los tracks son perfectos. Haciendo trekking, lo llevo en el bolsillo del patalon y tambien va muy bien. Obtengo unos tracks muy precisos.

Saludos

UH1169

thank you for your hints, the s8 came into my attention because of its size, ill check it out.

@ ineam: thank your very much, those professional level GIS devices from trimble led me into the GNSS world.. now i am getting close to the topic.

e,g, check this out:
https://www.mdpi.com/2079-9292/8/1/91/htm

already the introduction is very interesting

but as the intro suspects (study results), the antenna of the smartfones lead to fuzzy signals.
thus, i am thinking about an external GNSS bluetooth device which connects to oruxmaps.

however, GNSS capable devices are listed here:

https://developer.android.com/guide/topics/sensors/gnss




lneam

hi UH1169,

about xiaomi Mi8, my personal opinion is "stay away".
you can see those hi-res pics
https://i.imgur.com/psjJT9O.jpg
https://i.imgur.com/5smWMpC.jpg
https://i.imgur.com/5YPhSc2.jpg

from this review site
https://www.notebookcheck.net/Xiaomi-Mi-8-Smartphone-Review.413848.0.html
-----------------

about external GNSS receiver

1. if you or some else knows some electronics you can use u-blox F9T
www.gnss.store/gnss-gps-modules/102-zed-f9p-rtk-receiver-board-with-multiband-antenna-l1-l2-lis3mdl.html
www.gnss.store/gnss-gps-modules/108-ublox-zed-f9p-rtk-gnss-receiver-board-with-sma-base-or-rover.html
www.gnss.store/gnss-gps-modules/100-ublox-zed-f9p-rtk-gnss-receiver-board-with-sma-base-or-rover.html

www.gnss.store/rf-gps-antennas/28-high-performance-multi-band-gnss-active-quad-helix-antenna-for-rtk.html
www.gnss.store/rf-gps-antennas/26-ublox-ann-mb-multi-band-high-precision-gnss-antennas.html
www.gnss.store/rf-gps-antennas/25-high-performance-active-gps-antenna.html

2. or you can buy u-blox F9P
https://store-drotek.com/912-sirius-rtk-gnss-base-f9p.html

T vesrion use SBAS
P version don't use SBAS
ublox series 9 use dual band gnss'

lneam

Quote from: UH1169 on May 22, 2020, 12:01:27 PM
but as the intro suspects (study results), the antenna of the smartfones lead to fuzzy signals.

that's why i use my smartphone devices - only for navigation- purposes
no sim card, into airplane mode, with disabled wifi, bluetooth, nfc, irda sensor, etc

UH1169

Quote from: lneam on May 22, 2020, 06:17:29 PM

>>about xiaomi Mi8, my personal opinion is "stay away".

thank you, it is a frustrating topic. a analysis of the Mi8 resulted in  1-2 meters accuracy

see here:

https://www.mdpi.com/2079-9292/8/1/91/htm

with this in mind, chances are good to get an similar bad accuracy in spite of an GNSS dual freq. chipset with other devices :-(
currently i have a look on P30 and Pixel4 (both dual freq. GNSS).


UH1169

Quote from: lneam on May 22, 2020, 06:17:29 PM
hi UH1169,

>>about external GNSS receiver

the prices goes up with these sort of hardware... i noticed intersing hardware from the following companies:
Bad Elf
Trimble https://geospatial.trimble.com/products-and-solutions/trimble-r1
EOS Arrow Series e.g. the flagship: https://www.agsgis.com/Eos-Arrow-Gold-Basic_p_17.html

i think about wheter its more accurate to use an simple external GPS/gnss bluetooth unit with a cheap smartfone/orux
that purchasing a 400eur+ dual freq. GNSS Smartfone and getting a similar accuracy like with your screenshots (mi8) ...

like
navilock gns 2000 or
garmin glo or
holux rcv 3000
...

maybe this is better, in case those BT trackers are fixed in a good position (on top of the rucksack or shoulder) it could be that the accuracy is better
as using a dual freq. gnss smartfone when it sits near the body in a e.g. chest pocket....



UH1169

study of the (much) increased power consumption of dual frequency gnss :

https://arxiv.org/pdf/1910.13041.pdf


lneam

Hi UH1169,

into my first post i present 4 stand alone (with screen) posible solutions from 200-2000$. The solution 3 (665€ excl. VAT) and 4 (1500€ excl. VAT) are using ublox M8 with 1 band gnss receiver and the user can have around of 70cm static accuracy. At this moment there none typical android with this accuracy.

when you said "i am thinking about an external GNSS bluetooth device which connects to oruxmaps", i suggest 2 posisble solutions with ublox 9 series (L1 + L2 "yes two") from 300-400 $

all of my suggestions is working only from satellites without the need of RTK, with real time results - no need for post procesing
of course you are the person who will make the choose

UH1169

here is a test of the badelf gnss surveyor. especially for running it is quite inaccurate. note that this was on flat terrain, in steep mountains or gorges, the accuracy will become even more worse

https://www.fulcrumapp.com/blog/gps-testing-with-bad-elf-gnss-surveyor/

for me it llooks like it makes no sense to use an external sensor. above performance is similar to my old motorola defy plus ( tuned settings).


UH1169

Quote from: UH1169 on May 23, 2020, 03:10:40 PM
Quote from: lneam on May 22, 2020, 06:17:29 PM

>>about xiaomi Mi8, my personal opinion is "stay away".

thank you, it is a frustrating topic. a analysis of the Mi8 resulted in  1-2 meters accuracy

see here:

https://www.mdpi.com/2079-9292/8/1/91/htm

with this in mind, chances are good to get an similar bad accuracy in spite of an GNSS dual freq. chipset with other devices :-(
currently i have a look on P30 and Pixel4 (both dual freq. GNSS).

the antenna is the problem, see here

https://www.sciencedirect.com/science/article/pii/S0263224120301718

UH1169

regarding some testing reports and user feedback on amayon what i have read , this external BT GPS tracker seems to be "good" (better than Garmin and some other).
Note the sub 100$ price and the sub 100 gramm weight. this makes it feasable for hiking/running, mounted on top of the rucksack or similar good
position. drawback : it is not waterproof or similar IP rating

DE https://www.navilock.de/produkt/60324/merkmale.html

EN https://www.navilock.de/produkt/60324/merkmale.html?setLanguage=en

SP https://www.navilock.de/produkt/60324/merkmale.html?setLanguage=es


is it possible to run oruxmaps and record tracks with an external GPS/bluetooth tracker and let the location service in android deactivated ? (to save battery)