Tree survey equipment

[openspaceman]

That's simple?

 

I didn't even know that you could show gps co-ordinates on a photo. Is that on a camera or a phone? Technology is a black hole to me, I learn to do what I need but that's about it.

 

Yes on a samsung smartphone at least, just switch location tags on in the settings menu.

 

Before I had a smartphone I would take a photo of my garmin GPS clock, this would enable me then to synchronise my photos to my GPX file of my track. There is a bit of shareware that then geotags the photos from the timestamp and any offset calculated for the difference between the phone clock and GPS time.

 

It's over 5 years since I did the survey and resurvey but the firm had no budget for any special equipment.

[openspaceman]

Which GPS though? I had a garmin years ago for walking and the level of accuracy left a bit to be desired. Saying that I did read last night that Clinton passed a bill around 2000 to take the inbuilt inaccuracies out of the system. Fascinating stuff when you start to learn how it all works.

 

Yes that was Selective Availability it randomly diluted the precision by about 50m., Nowadays if you stand in the same spot for a couple of minutes it gets within 2m if you have a good constellation of 4 or more satellites in reception.

 

 

 

This has all arisen due to a management survey with a lot of trees in close proximity. I could just tag each tree, but I'd like to try to map them for the future to assist the clients ongoing management policies.

 

What I found was the GPS trace always showed a sequential route from tree to tree such that there was never a case of a tree being marked on the wrong side of its neighbour even though the whole trace could be a few metres out from the map.

 

Thanks for the suggestion. I wonder at the accuracy of the gps on my i-phone:confused1:

 

I don't see why the I phone would be different from dedicated standard GPS as they all tend to use the same chips. Differences in accuracy are obtained by being to receive different information, often by integrating a differential channel local to you, A stationary base station receives the same GPS signal as your hand held device, as it knows its position precisely it can calculate a correction for the incoming GPS signal (due to "noise" and deviations caused by atmospheric effect)it then broadcasts the correction to a differential enabled device which gets the accuracy down to a few centimetres. We did hire a Trimble with a pole and a receiver on top for some other jobs, which I did not participate in, but the additional accuracy wasn't warranted for vegetation management.

[Gary Prentice]

Yes that was Selective Availability it randomly diluted the precision by about 50m., Nowadays if you stand in the same spot for a couple of minutes it gets within 2m if you have a good constellation of 4 or more satellites in reception.

 

What I found was the GPS trace always showed a sequential route from tree to tree such that there was never a case of a tree being marked on the wrong side of its neighbour even though the whole trace could be a few metres out from the map.

 

I don't see why the I phone would be different from dedicated standard GPS as they all tend to use the same chips. Differences in accuracy are obtained by being to receive different information, often by integrating a differential channel local to you, A stationary base station receives the same GPS signal as your hand held device, as it knows its position precisely it can calculate a correction for the incoming GPS signal (due to "noise" and deviations caused by atmospheric effect)it then broadcasts the correction to a differential enabled device which gets the accuracy down to a few centimetres. We did hire a Trimble with a pole and a receiver on top for some other jobs, which I did not participate in, but the additional accuracy wasn't warranted for vegetation management.

 

From my reading on Trimbles website I actually understand this:thumbup1:

 

I'm off to play with my I-phone to see how I get on. Ideally, in the not too distant future, I could do with sorting all this out properly, the tablet isn't ideal or quick for data collection and it's a lot of un-necessary work correlating everything into the report again.

 

Thank you kindly

[openspaceman]

From my reading on Trimbles website I actually understand this:thumbup1:

 

I'm off to play with my I-phone to see how I get on. Ideally, in the not too distant future, I could do with sorting all this out properly, the tablet isn't ideal or quick for data collection and it's a lot of un-necessary work correlating everything into the report again.

 

Thank you kindly

 

 

Have a try with this photo of a local battlefield taken this morning.

 

save it and open it in an image viewer, I have had to revert to a windows emulator running Irfanview which I recomend as a useful download.

 

Then goto the menu toolbar and select "image", then "information" , then "exif info" then "view in google earth or geohack" and you will see how owners treat an SSSI and NNR

 

Actually given the previous history this is not a bad thing as it's how the place evolved.

[Island Lescure]

Don't know how Keytree works(I have gone with Pear Tech), but on mine (Sony tablet) I get the map of the site I am surveying, plot the tree on that map (which is integrated in PocketGis) then enter my tree data and onto the next one. Once home, I just export the info into the Pear program and everything is in place with associated info (in the case of BS5837s) on the map.

If I want to use the tablet's GPS, I just turn it on and it should somewhat accurately display my position on the map and there I plot the tree. To improve accuracy on the tablet/phone I was suggested something similar to what you showed:

Cheap/less accurate: Qstarz BT-Q818x Bluetooth Sat Nav GPS Receiver or Universal Bluetooth GPS Receiver (Wirelessly Add GPS To Your Devices),

Expensive/accurate: Arrow 100 or 200

I hope this helps.

 

Island