[CANUFNET] High precision (+/- 10cm) tree location

Tue Nov 6 13:07:16 EST 2018

The only device I’ve ever used that can get sub metre accuracy under tree canopy is the Trimble Geo 7x, as it has a built in laser rangefinder which can shoot under the tree crown to provide an offset from an accurate GPS reading. I have one and it works great, but the windows mobile 6.5 software is starting to feel very dated.

There may be other solutions that can provide a laser offset via a rangefinder linked to the GPS unit with Bluetooth, but I haven’t much experience with them. Arcpad can do this, but you’re back to the issue of generally using windows mobile again.

Best

Scott

Scott Fairley MA(landarch) MSc(for) LMLI M.arbor.A
consulting arborist|landscape designer

American Society of Consulting Arborists Member
PNWISA Chapter Member
ISA Certified Arborist UI-1192A
TRAQ Tree Risk Assessor
UK Licentiate Landscape Architect
UK Professional Member of the Arboricultural Association
UK Professional Tree Risk Assessor (PTI) LANTRA Awards

email: scott at treesandlandscape.com
web: www.treesandlandscape.com
Tel: 1-(778)-583-6098

> On 5 Nov 2018, at 18:30, Maurice, Jerome via CANUFNET <canufnet at list.web.net> wrote:
> 
> Hi Canufnet,
> 
> I came across a recent discussion about tree geolocation tools used by some urban foresters (see below). Based on practical experience, is anyone able to recommend one or more devices that are highly accurate (+/- 20cm) for tree inventory ? what would be a reasonable target under closed canopy cover (20cm ? 50cm ? 1m ?)
> 
> Thanks a lot.
> 
> Jérôme Maurice, Ing.f. M.Sc.
> 
> 
> -----Message d'origine-----
> De : CANUFNET [mailto:canufnet-bounces at list.web.net] De la part de Art Maat via CANUFNET
> Envoyé : 19 janvier 2017 17:35
> À : Marie-Hélène Sauvé; Canadian Urban Forest Network
> Objet : Re: [CANUFNET] tree protection
> 
> Mobile software is available from Histree for plotting and or surveying tree locations with species, condition, images and other variable attribute data in field. 
> 
> As well GPS hardware is available and can connect to Android or iOS devices via Bluetooth resulting in sub meter accuracy point locations.  Additionally using Histree and on board satelite views a user can also visually reference a location by moving the map while the pin is stationary. Much like Uber interface. 
> 
> Regards,
> Art Maat
> 780-937-4056
> 
>> On Jan 19, 2017, at 3:08 PM, Marie-Hélène Sauvé via CANUFNET <canufnet at list.web.net> wrote:
>> 
>> Hi there,
>> 
>> Just to adjust something about GPS and urban forestry: there exists many
>> types of devices that are accurate enough (+/-10cm precision) to make a very
>> good distinction between two trees located nearby (and even the property -
>> if it's a public tree or not). Those devices are way more expensive than
>> those easy-to-use Garmin or other GPS device used traditionally in forestry.
>> Those high-level precision GPS are used by some consultants in the Greater
>> Montréal. So YES, it may be used and applied. The user has to know how to
>> use it properly though; GIS skills are required!
>> 
>> Cheers,
>> 
>> Marie-Hélène Sauvé
>> 
>> 
>> 
>> -----Message d'origine-----
>> De : CANUFNET [mailto:canufnet-bounces at list.web.net] De la part de via
>> CANUFNET
>> Envoyé : 19 janvier 2017 13:12
>> À : jd at dunster.ca; Julian Dunster; Michael Richardson; Canadian Urban Forest
>> Network
>> Objet : Re: [CANUFNET] tree protection
>> 
>> Unfortunately GPS is not accurate enough to plot trees, especially when
>> landmarks that are accurately located by a surveyor aren't close by (i.e. a
>> forest or large natural area).  GPS's currently available don't have the
>> resolution to separate two trees that are 2 feet apart, or may be on the
>> other side of a property line with 100% accuracy.  A critical point. It's a
>> help but not the solution, yet.
>> 
>> CAD and GIS are great for plotting the data (we use both) but the locations
>> need to be accurate to start with. The days of drawing-in a dot by hand on a
>> site plan are gone.
>> 
>> Stephen Smith
>> ISA Certified Arborist, Urban Forester
>> Urban Forest Associates Inc.
>> -----Original Message-----
>> From: Julian Dunster via CANUFNET
>> Sent: Thursday, January 19, 2017 11:56 AM
>> To: Michael Richardson ; Canadian Urban Forest Network
>> Subject: Re: [CANUFNET] tree protection
>> 
>> Many of arborists in Britain regularly use GPS, GIS, and CAD routinely for
>> development projects. One of them developed special CAD software for the
>> purpose. The lack of its use in Canada almost certainly reflects a lack it
>> being taught in curricula, as part of professional practice. We still focus
>> on pruning, planting, fertilising and tree stuff, all of which is fine but
>> needs expanding to the 21st century to include effective use of technology.
>> Several of my colleagues in BC use CAD all the time. I use GPS and GIS.
>> 
>> We need to expand the horizon of what arboriculture and urban forestry might
>> / should entail. At the same time we can also inform surveyors and
>> architects of we expect them to produce - such as CAD symbols for canopy
>> that are scaled to reality on the ground, not simply rubber stamped on a
>> plan, all at the same size (a pet peeve).
>> 
>> On Behalf of Dunster and Associates Environmental Consultants Ltd.
>> 
>> 
>> Dr. Julian A Dunster R.P.F., R.P.P.., M.C.I.P., ISA Certified Arborist, ASCA
>> Registered Consulting Arborist # 378, ISA Tree Risk Assessment Qualified BC
>> Wildlife Danger Tree Assessor Honourary Life Member ISA + PNWISA
>> 
>> North American distributor for Rinntech
>> www.dunster.ca
>> 
>>> 
>>> Some interesting thoughts here.
>>> 
>>> Those little dots; most arborists I know do not have the equipment or 
>>> expertise to to locate trees with any precision, nor the GIS software 
>>> to plot them.  If an arborist is using a plan created by a surveyor 
>>> than surely the arborist must locate and plot not the tree, but the 
>>> entire trunk diameter or root collar/trunk flare with the same 
>>> accuracy and precision.
>>> 
>>> 
>>> 
>>> 
>> 

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