From 1251a63e4d5f8d5f4c6c1b3190698e4c674fc4a4 Mon Sep 17 00:00:00 2001
From: Philip Sargent <philip.sargent@gmail.com>
Date: Tue, 5 May 2026 15:22:57 +0100
Subject: [PATCH] compass logo added, accuracy added - online edit of
 handbook/computing/myphone.html

---
 handbook/computing/myphone.html | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/handbook/computing/myphone.html b/handbook/computing/myphone.html
index 02e64d114..0c1f2a084 100644
--- a/handbook/computing/myphone.html
+++ b/handbook/computing/myphone.html
@@ -40,10 +40,13 @@ For the latest updates on why "battery saver" kills accurate location for the mo
 <p>Do <em>not</em> select the "high accuracy" location setting on your phone. Mostly this will snap your position to the nearest cafe or bierstube: by default it will use the nearest WiFi it can find and assume that you are there, and will ignore the perfectly reasonable GPS position it has recorded directly.
   <p>This is all explained by Google <a href="https://support.google.com/maps/answer/2839911?hl=en&co=GENIE.Platform=Android">here</a>. 
     
-    <p>On the plateau, this "high accuracy" mode will simply give you the <em>wrong</em> position if it can't get an excellent GPS fix (but we only need a "good" one). There is poor cell tower reception too, so trying to use that for location is just as bad. 
+<div class="onright"> <figure> <a href='/handbook/survey/l/insert-ringed.html'><img src='/handbook/survey/t/insert-ringed.jpg' /></a>&nbsp;<br /><caption>11 meter "accuracy"</caption></figure></div>    <p>On the plateau, this "high accuracy" mode will simply give you the <em>wrong</em> position if it can't get an excellent GPS fix (but we only need a "good" one). There is poor cell tower reception too, so trying to use that for location is just as bad. 
       <p>What you want is GPS and <em>only</em> GPS (more precisely <a href="https://en.wikipedia.org/wiki/GNSS_applications">GNSS</a>: which includes GPS, Glosnas, Beidou, Galileo etc.). 
         <p>If you do not have a good GPS fix, <em>you want to know that</em>, not be given some confabulated guesstimate by whatever some programmer for Apple or Android thought your might want.
           
+          <p>Even if you do everything right, it is very common for the horizontal accuracy on the plateau to be 10m or worse: see the image showing "E H/V 11.2/8.6m" (E)stimated (H)orizontal 11.2m (Acc)uracy. (The vertical accuracy is just completely bogus, ignore it.) This is at the entrance to 1623/196.
+
+           
 <h4>Airplane Mode</h4>
 <p>If all that config sounds too tricky, or if you have done it but are not confident that it works, just put your phone into <a href="https://en.wikipedia.org/wiki/Airplane_mode">Airplane Mode</a> when on the plateau, and re-start your GPS app after you do so.