From 284d3ad69f6fdb5fae458f667f91fdebb6ea383e Mon Sep 17 00:00:00 2001 From: Philip Sargent Date: Tue, 3 Feb 2026 12:21:09 +0000 Subject: [PATCH] fix - online edit of handbook/computing/myphone.html - on dev machine 'Mohawk' --- handbook/computing/myphone.html | 54 ++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 25 deletions(-) diff --git a/handbook/computing/myphone.html b/handbook/computing/myphone.html index b23050752..f11ad5479 100644 --- a/handbook/computing/myphone.html +++ b/handbook/computing/myphone.html @@ -1,18 +1,26 @@ My Phone on Expo

My Phone on Expo

Before Expo

-

Since 2019 it has become apparent that many people have not been properly prepared for Expo. +

Since 2019 it has become apparent that many people have not been properly prepared for Expo.

This is what you need to do: +

-

For the latest updates for the most recent phones, go to: dontkillmyapp.com +

  • Fix the seriously broken default for recording your GPS track when you are walking in the plateau.
       +
    +
  • Download and install OSMand +
  • Download and install GPStest +  + +

    +  
    +For the latest updates on why "battery saver" kills accurate location for the most recent phones, go to: dontkillmyapp.com

    The reason why

    -

    Phones assume that you are walking along streets, or running along tracks or cycling. They are very bad at making the right guesses for the Totes Gebirge plateau. +

    Phones assume that you are walking along streets, or running along tracks or cycling. They are very, very bad at making the right guesses on the Totes Gebirge plateau.

    Location, location, location

    @@ -51,15 +59,14 @@

    Phone camera procedure: Cave entrances

    We have a separate page specifically on recording cave entrances by GPS in the survey handbook. - - - - -

    Share location (using Google Maps app or something equivalent) with useful people on expo

    + tbd

    So that we can spend less time looking for the body in horrible conditions...

    [someone write this is a less frightening way, please?] + +

    You will probably be familiar with real-time, continuous sharing of location using Google Maps or Apple, but there are several apps that do this. +

    Note that you do want continuous location sharing, so that when you fall down a hole and lose signal, we know where the top of the hole is.

    Disabling GPS "energy saving" modes

    Why

    @@ -71,30 +78,27 @@ tbd

    How: with OSMand

    If you have standard battery saving set up, when you start up OSMand and start recording a track, it will do a popup telling you about how to turn off battery saving. -

    WHat you need to do seems to be correlated with how expensive your phone is. A Xioami Redmi 12 phone in 2024 worked with just the OSMand and battery saving fetures disabled as described above. But in 2025 a Blackview Wave8 phone would not produce a useable OSMand track at all until the "GPStest" app (see below) was also run continuously and with notifications and logging enabled. +

    What you need to do seems to be correlated with how expensive your phone is. A Xioami Redmi 12 phone in 2024 worked with just the OSMand and battery saving fetures disabled as described above. But in 2025 a Blackview Wave8 phone would not produce a useable OSMand track at all until the "GPStest" app (see below) was also run continuously and with notifications and logging enabled. -

    Calibrate/document your phone's capabilities

    -
    -Install the "GPS Test" app, this one: GPS TEST and check whether your phone is using SBAS "Satellite-based Augmentation Services", which is another name for EGNOS, the differential GPS system. -You need to record if SBAS is in operation whenever you record the position of a cave entrance (and ideally whenever you take a photo too, but that would be unrealistic). [ Philip Balister takes a screen-shot of the GPStest screen whenever he want a proper GPS location. A notebook and pencil are also valuable adjuncts when looking at lots of entrances: use the timestamp on the screenshots to correlate everything. ] +

    Temporary Google Photos

    +

    When anyone shares photos on a "Shared Album" in Google Photos, they are only visible so long as the original photographer keeps the photos on their device: there are loads of photos by Harry Kettle from 2023 which are visible only as blank rectangles on the Shared Album because he has cleared out his photo album on his google account. (This really is a "share" not an "upload".)

    So unless the photo is utterly trivial and disposable, please also upload the photos using the "Upload Photos" page on the website before you delete them from your device.

    We would rather you didn't use Google Photos at all really, but people will willy-nilly, so let's at least use the same Google photos album each year. -

    The future

    -

    Location fixing: How to obtain a fixed point for a cave survey (2020) "Galileo High Accuracy Service (HAS) is due to become partly available in 2022 and fully available in 2024, which will offer RTPPP for free around the world, both via satellite and network connections. And there will be much rejoicing. " - This is an excellent article and nearly all of it is still absolutely true, e.g.: -

    Keep the device very still. If the position shown by GPSTest slowly refines then stops updating within a minute or two, or shows only the last digit changing slowly, then your device cannot be used for averaging. A device with 1 metre accuracy still shows the 6th and 7th decimal place digits of the longitude and latitude updating every second or so (that is a roughly 10 cm wobble every second). Unless your device can actually do 1 cm accuracy, you should be seeing those numbers change! In general, this makes most phones unusable for this purpose"
    -

    Unfortunately RTPPP has not actually caught on [2025] and it is still only available for experts and phones supporting L2 and L5 frequencies have been slower to appear than we hoped. Read Wikipedia on Real-time kinematic positioning (RTK). - +

    Cave Entrance Location

    +

    This is a whole other thing entirely. It is much more complicated than you might think to do it to proper 'expo' standard. See our Locating entrances by GPS page. +

    Go on to Saving your GPS tracks
    Go on to Next survey guide page - 'Base Camp: getting it in to the computer'

    -Your phone on expo - Do not select the "high accuracy" location setting on your phone
    +
    +Your phone on expo - Do not select the "high accuracy" location setting on your phone (this page)
    GPS essentials on the plateau - Safety information
    Photo GPS - Is unreliable unless you follow procedure
    -Locating entrances by GPS - from the survey handbook section
    + Locating Entrances - expo recommended methods
    +