<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Hi,</div><div><br></div><div>I looked at the page.It looks like a neat project! Buy time you buy a case, antenna... (I don’t think they come with on), your back into the price range of a forestry grade survey GPS unit. I think the Emild single band gps (<a href="https://emlid.com/reachrs/">https://emlid.com/reachrs/ </a>) is probably a better choice unless you really want to make this a learning project. But if I understand you are really on a shoe string budget.</div><div><br></div><div>None of these Gps, by the way, would beat and old theodolite... if you can establish or find a good gps position (look for the city or state geomatics services) or survey point, a théodolite would give you survey grade positions. City have these points on every few blocks. You may be able to find A theodolite for free. A second hand TotalStation could be better but that will be more difficult to find in those price ranges (Shoe string). You can also rent equipment or find a college that would take this up as a teaching opportunity.</div><div><br></div><div>Have fun!</div><div><br><div dir="ltr">Nicolas Cadieux<div>Ça va bien aller!</div></div><div dir="ltr"><br><blockquote type="cite">Le 23 mai 2020 à 13:52, Bernd Vogelgesang <bernd.vogelgesang@gmx.de> a écrit :<br><br></blockquote></div><blockquote type="cite"><div dir="ltr">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<p>Unfortunately, the Forest Service Website went offline (maybe
this thread caused so much traffic that it broke down? ;) )<br>
</p>
<p>I'm also desperately searching for an affordable way to have at
least some decent accuracy. I do not need submeter, but it would
be fantastic if it was possible to achieve meter accuracy.<br>
I gave up on that Garmin stuff. They might be accurate, but I have
no chance to control this until I return home and put the recorded
data on screen over an aerial image. Those screens are a joke, and
the business logic that prevents me to put reasonable aerial
imagery on the device without paying a fortune is apita. Maybe
this improved cause I last checked 5 years ago.</p>
<p>Mobile phones at least in my case seem to get worse. My Motorola
from 2016 had an accuracy of less than 4 meters, most of the time
less than 2.<br>
Now I bought a Huawei 30 pro cause of the camera (my first phone
with nice pictures!), but the accuracy is a nightmare. The
position is jumping around like a dog on rabies.<br>
I also bought a bluetooth device (Navilock BT-821G) two years ago.
This is much better than the phones GPS, tho it only receives 20
satellites maximum (The phone claims to receive some 40). But also
this device sometimes, when walking a transect, is constantly 5
meters off the track for several several minutes.</p>
<p>As apps averaging the positions were mentioned: Does anyone have
a recommendation on such apps (for Android)? I found some, but the
usability was not that great, and some even didn't enhance
anything.</p>
<p>Furthermore, I stumble upon an article about a module with u-blox
chip. <a class="moz-txt-link-freetext" href="https://www.sparkfun.com/products/16481">https://www.sparkfun.com/products/16481</a><br>
Does anyone have any experience with modules like this and what
else is needed? The description of all the stuff leaves me a bit
puzzled.</p>
<p>Cheers,</p>
<p>Bernd<br>
</p>
<div class="moz-cite-prefix">On 23.05.20 18:17, Michael.Dodd wrote:<br>
</div>
<blockquote type="cite" cite="mid:LNXP265MB10663D497A39AC54B4B74D4DB0B50@LNXP265MB1066.GBRP265.PROD.OUTLOOK.COM">
<div>
<a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.2041-210X.2011.00118.x" id="LPlnk857492" moz-do-not-send="true">https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.2041-210X.2011.00118.x</a>
I did this quite a few years ago but in the graph in
supplimentary material it shows how the accuracy of one consumer
grade gps varies over time (at a fixed point). At the time I
also did a lot more measurements using mobile phones and
consumer grade units on a grid of points in the field, that was
not published but basically the phones were often as good as if
not better than the consumer grade gps units especially when
using certain apps to average points.<br>
</div>
<div id="LPBorder_GTaHR0cHM6Ly9iZXNqb3VybmFscy5vbmxpbmVsaWJyYXJ5LndpbGV5LmNvbS9kb2kvZnVsbC8xMC4xMTExL2ouMjA0MS0yMTBYLjIwMTEuMDAxMTgueA.." class="LPBorder618713" contenteditable="false">
<table id="LPContainer618713" role="presentation">
<tbody>
<tr>
<td>
<div id="LPImageContainer618713">
<a target="_blank" id="LPImageAnchor618713" href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.2041-210X.2011.00118.x" moz-do-not-send="true"><img id="LPThumbnailImageId618713" alt="" moz-do-not-send="true" width="123" height="160" data-unique-identifier=""></a></div>
</td>
<td>
<div id="LPTitle618713">
<a target="_blank" id="LPUrlAnchor618713" href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.2041-210X.2011.00118.x" moz-do-not-send="true">Where are my quadrats?
Positional accuracy in fieldwork - Dodd - 2011 -
Methods in Ecology and Evolution - Wiley Online
Library</a></div>
<div id="LPDescription618713">
Introduction. There has been much written about
sampling design, spatial scale and the need for
permanent plots in ecological long‐term monitoring,
for example, the paper on spatial scaling in ecology
has been cited over 1500 times, but one frequently
ignored issue, intimately associated with sampling
design, scale and permanence of plots, is how to
locate positions accurately.</div>
<div id="LPMetadata618713">
besjournals.onlinelibrary.wiley.com</div>
</td>
</tr>
</tbody>
</table>
</div>
<br>
<hr tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><b>From:</b> Qgis-user
<a class="moz-txt-link-rfc2396E" href="mailto:qgis-user-bounces@lists.osgeo.org"><qgis-user-bounces@lists.osgeo.org></a> on behalf of Nicolas
Cadieux <a class="moz-txt-link-rfc2396E" href="mailto:nicolas.cadieux@archeotec.ca"><nicolas.cadieux@archeotec.ca></a><br>
<b>Sent:</b> 23 May 2020 16:34<br>
<b>To:</b> Randal Hale <a class="moz-txt-link-rfc2396E" href="mailto:rjhale@northrivergeographic.com"><rjhale@northrivergeographic.com></a><br>
<b>Cc:</b> <a class="moz-txt-link-abbreviated" href="mailto:qgis-user@lists.osgeo.org">qgis-user@lists.osgeo.org</a>
<a class="moz-txt-link-rfc2396E" href="mailto:qgis-user@lists.osgeo.org"><qgis-user@lists.osgeo.org></a><br>
<b>Subject:</b> Re: [Qgis-user] wishing for accurate
lattitude/longitude from a cell phone
<div> </div>
</div>
<div class="BodyFragment"><span>
<div class="PlainText">CAUTION: This mail comes from outside
the University. Please consider this before opening
attachments, clicking links, or acting on the content.<br>
<br>
Hi,<br>
<br>
This is a very interesting list. It basically confirms what
I thought. Consumer Point and shoot deceives are all around
2-6m with no canopy. The average multiple positions
basically give you a better idea as a gps may get lucky. It
would be nice to have the full methodology for this and more
data (like the number of satellite and the position of the
constellation and the gps price list) but it’s very
interesting none the less. I was also happy that the data
confirms the precision of the gps Sx-Blue 11. This claims to
be sub meter and my tests indicated that on our office unit
but it’s nice to see it done elsewhere. For about 2000$,
this gps is pretty good. As for the rest, the difference
between 150$ and 1000$ is probably more a function of the
options (like maps and screen size...) and not a question of
precision. It would be nice to know what gps chips they are
running...<br>
<br>
Interesting thing also is that based on my reviewing the
data on my phone (without graph or cross tabulation tables)
is that the Glonas Constellation does not seem to help
much. Quick stats on this list would confirm this. Maybe
this is just a figment of my imagination because there’s
only so much information you can grad without running proper
stats.<br>
<br>
Thanks for the post.<br>
<br>
Nicolas Cadieux<br>
Ça va bien aller!<br>
<br>
> Le 23 mai 2020 à 09:02, Randal Hale
<a class="moz-txt-link-rfc2396E" href="mailto:rjhale@northrivergeographic.com"><rjhale@northrivergeographic.com></a> a écrit :<br>
><br>
> One other thing that may or may not be of use but the
USDA Forest Service Publishes a GPS Receiver Report that
covers phones - and that's helped if I've had a client go
"Well I have a Apple <something> or a Android
<thing>". At least I feel slightly better going "good
enough" or "no not good enough".<br>
><br>
> It should be good worldwide (but I will admit I think
phones are my 'tech ceiling' these days) but your mileage
may vary.<br>
><br>
> <a href="https://www.fs.fed.us/database/gps/mtdcrept/accuracy/index.htm" moz-do-not-send="true">https://www.fs.fed.us/database/gps/mtdcrept/accuracy/index.htm</a><br>
><br>
> Randy<br>
><br>
>> On 5/22/20 8:55 PM, Priv.-Doz. Dr. Maria Shinoto
wrote:<br>
>> Somehow I did not follow the discussion, but like
to add some of our experience.<br>
>><br>
>> We are doing field work in a remote region in the
southern Japanese mountains, archaeological surveys on the
ground based on LiDAR data.<br>
>><br>
>> A simple Garmin etrex10 is mostly reliable in an
area of 40cm by 40cm around a measured point, if used
repeatedly at this point and the point is located in the
middle of a valley. Even cell phones do a good enough job.
As soon as we get closer to the steep slopes, the accuracy
of the Garmin is less than 5 to 10 meters. We can check this
with the detailed LiDAR based map, and geologists told us,
that even an expensive device could not be more precise
under these conditions. So we decided to measure
traditionally on the ground if precise measure is necessary,
otherwise note the GPS data and the location as shown in the
map.<br>
>><br>
>> To sum up, we came to the conclusion not to spend
money on an expensive GPS that may not work in the shadow of
steep slopes -- or in the streets of New York. -- I
appreciate any additional advice, and hope that this
experience can save Steve's organisation some money...<br>
>><br>
>> Best,<br>
>> Maria<br>
>><br>
>><br>
>><br>
>>>> Am 23.05.2020 um 03:54 schrieb Stephen
Sacks <a class="moz-txt-link-rfc2396E" href="mailto:sacks44@earthlink.net"><sacks44@earthlink.net></a>:<br>
>>><br>
>>> In order to make widely available some wise
advice, I'm sending to this list a message I received from
Neil B. In addition to Neil's message below, I want to
mention that Nicolas Cadieux also provided similar
information, saying I'd have to pay around $1,000 for
equipment that gives consistently accurate location
coordinates. And thanks, also to Falk Huettmann and Bernd
Vogelgesang for their replies.<br>
>>><br>
>>><br>
>>> Message from Neil B:<br>
>>><br>
>>> Hello Stephen.<br>
>>> Glad that you're having su<br>
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