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screenshot GPStest - online edit of handbook/survey/gps.htm

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Philip Sargent
2026-05-06 22:23:24 +01:00
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handbook/survey/gps.htm
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@@ -83,7 +83,7 @@ or a cairn, for example - we don't use paint any more) and place
the GPS on the point. Don't build a cairn, they don't last for decades and we have survey stations that provide permanent locations. Give the GPS device a the GPS on the point. Don't build a cairn, they don't last for decades and we have survey stations that provide permanent locations. Give the GPS device a
minute to get a fairly good fix (the first figure reported may be minute to get a fairly good fix (the first figure reported may be
quite a way out is you have been moving). Then mark quite a way out is you have been moving). Then mark
the point as a "waypoint" in OSMand. the point as a "waypoint" in OSMand AND, without moving the phone, take a screenshot of the GPStest screen (see below) showing the lat./long., the time and the various accuracy metrics.
<h3>Camera locations</h3> <h3>Camera locations</h3>
@@ -91,7 +91,7 @@ the point as a "waypoint" in OSMand.
<figure class=onright><a href='/handbook/computing/l/camera-ne-track.html'><img src='/handbook/computing/t/camera-ne-track.jpg' /></a><figcaption>Camera photo locations are not<br> on the track!</figcaption> <figure class=onright><a href='/handbook/computing/l/camera-ne-track.html'><img src='/handbook/computing/t/camera-ne-track.jpg' /></a><figcaption>Camera photo locations are not<br> on the track!</figcaption>
</figure> </figure>
<p>Your <em>camera</em> will use the same location settings as the rest of your phone, but sometimes with a bit of a delay. We have lots of examples of geo-located photos where the recorded location is alctually the location of the <em>previous</em> photo because someone has taken a quick photo but the phone hasn't had time after waking up to get a location, so it uses the previous one! And doesn't tell you!! <p>Your <em>camera</em> will use the same location settings as the rest of your phone, but sometimes with a bit of a delay. We have lots of examples of geo-located photos where the recorded location is actually the location of the <em>previous</em> photo because someone has taken a quick photo but the phone hasn't had time after waking up to get a location, so it uses the previous one! And doesn't tell you!!
<p>So when taking a photo of an entrance, always take one photo; delete it, and take another. This will give your phone a chance to get synchronised properly. <p>So when taking a photo of an entrance, always take one photo; delete it, and take another. This will give your phone a chance to get synchronised properly.
@@ -111,7 +111,7 @@ track log, then record another waypoint at the same place just before you leave
so it's clear to someone examining the track log when you actually left. so it's clear to someone examining the track log when you actually left.
</p> </p>
<p>Averaging used to be very important, but today (2026) we have so many GNSS satellites in the sky that ionospheric effects are the significant error. These change slowly over 5 hours or so, so avergaing for a minute or and hour does nothing useful. You would need to average over several days. The solution for a fast fix is <a href="/handbook/computing/myphone.html#future">to use RTK</a>. <p>Averaging used to be very important, but today (2026) we have so many GNSS satellites in the sky that ionospheric effects are the significant error. These change slowly over 5 hours or so, so averaging for a minute or an hour does nothing useful. You would need to average over several days. The solution for a fast fix is <a href="/handbook/computing/myphone.html#future">to use RTK</a>.
<p>While the GPS is averaging your location, you can do something useful <p>While the GPS is averaging your location, you can do something useful
(like rigging the cave, doing a surface survey from the GPS point to the (like rigging the cave, doing a surface survey from the GPS point to the