Tree Radar Unit - Root Scans Using Ground Penetrating Radar

[Arboraeration]

Well, after over a year of planning, training, and shipping complications due to the COVID19 pandemic, we finally have our Tree Radar Unit out working in the UK. I am going to use this thread as a place for people to ask questions about the unit, show some pictures of the type of work we do with it and the results, and hopefully convert a few non-believers!! To start us off, firstly, I am going to explain how the unit works and showcase some of the results we are able to achieve with the unit! Secondly, I will describe the differences between our model and other units that have been trialled and used in the UK.

 

The Tree Radar Unit itself is produced by a company based in the USA and they have been developing the unit since the early 2000's. The unit comprises of a Radar Antenna that can be affixed to a cart or used freehand in tight spaces, a data logger and a tablet to interpret the results. The antenna sends out radio waves that detects root locations and sizes.

The Tree Radar Unit ™ sporting aftermarket Dunlop rain protection device

 

 

Once collected, the raw data is uploaded onto the TBA Roots software and analysed. This process is all completed manually relying on our training and experience using both the software and knowledge of the root systems of trees. The files are then merged and used to create the graphics below!

 

 

 

Virtual Trench

 

The Virtual Trench graphic displays the results in the same way as if a trench had been excavated through the soil, displaying root locations and depths. The horizontal lines are used to mark different depths of the soil for further analysis.

 

 

 

 

Root Morphology Map

 

 

 

 

 

The Root Morphology Map sets out a 2D computer generated image of the tree's root system. This can be overlaid in CAD drawings, plans and topographical surveys to allow planners to visualise the root system.

 

How does this system differ from earlier versions and others that are in use in the UK?

During initial testing in the mid 2000’s, there were a number of trials in the UK of the first version of the unit. Since then, there have been a numerous changes to the unit and the software to make it much more reliable and accurate. Currently, the Tree Radar Unit is available in two antenna versions; 900mhz and 400mhz. We operate a 900mhz unit, whereas all of the other units in the UK are 400mhz. The difference in these frequencies has a direct correlation between depth and sensitivity. The 400mhz unit may be able penetrate up to 3m depth, however, it can lack clarity and can struggle to detect smaller roots and roots which are closer to the surface. The 900mhz antenna, on the other hand, scans to 1.2m depth, but gives far more accurate results within this depth range allowing for clearer and more detailed diagrams, and ultimately, a more satisfied customer.

 

Hopefully, the above has given you some insight into how our unit works, and stay tuned over the next few days for images of the jobs we have worked on so far, and the results!

 

Any questions, fire away!

[daltontrees]

Informative, thanks.

 

Uptake if this service would be for me based on cost. It's a hard thing to specify but how much does iot cost to survey and report on a tree?

 

[Khriss]

And would buried services show up with this also  🤔  K

[Toad]

19 hours ago, Khriss said:

And would buried services show up with this also  🤔  K

You can see voids, or changes in density with the gpr which you would then need to relate back to c2s or tracing services with a CAT. You can't tell what you are looking at necessarily.

 

I've used them for utility surveys at work, They have their place and are useful, but by no means are they a standalone foolproof utility survey tool. 

 

From what I've experienced, the resolution of the gpr is about 10% of the depth scanned, so a 100mm duct is only visible to 1m or so. The different frequency used here may improve this though.

Edited February 14, 2021 by Toad

[Khriss]

@Toad am thinking  pot ends and the like, or non traced pipes, obvs you would also grab yr scanner before a dig. K

[Toad]

4 hours ago, Khriss said:

@Toad am thinking  pot ends and the like, or non traced pipes, obvs you would also grab yr scanner before a dig. K

I wouldn't want to put too much faith in it for that. Too easy to misinterpret the output without digging a slot trench to confirm, but that would probably defeat the object.

[Arboraeration]

Thanks for the replies

 

As Toad has said utilities can be picked up however for our purposes they are only identified in the analysis stage to be filtered out so they are not interpreted as roots. 

 

There are specific GPR systems that are for utilities that are set up slightly differently, usually without the recording functions and are used in a similar way to a CAT and Genny. 

 

Metal pipes, and electrical cable show up much brighter than plastic. 

 

[Arboraeration]

Validity 

 

Now the question that has come up a few times in conversation whilst discussing the unit  is how can you prove it? Obviously the results look very good on the computer showing that there are roots in X or Y location. However we decided early on that if we really wanted to promote this as a services we needed to be certain of the accuracy and validity of the results. So we scanned some roots and dug some holes with the airspade, below are a few photos 

 

 

 

 

 

 

 

 

We are planning, once Covid restrictions are over,  to undertake a few demo days around the country where we scan some trees and airspade some trenches along the scan lines to prove the results to Tree officers/Planners/ Arb Consultants etc. 

 

 

[Ian Clarke]

Validity 
 
Now the question that has come up a few times in conversation whilst discussing the unit  is how can you prove it? Obviously the results look very good on the computer showing that there are roots in X or Y location. However we decided early on that if we really wanted to promote this as a services we needed to be certain of the accuracy and validity of the results. So we scanned some roots and dug some holes with the airspade, below are a few photos 
 

 
 

 
 

 
 

 
We are planning, once Covid restrictions are over,  to undertake a few demo days around the country where we scan some trees and airspade some trenches along the scan lines to prove the results to Tree officers/Planners/ Arb Consultants etc. 
 
 

I hear the Arb assoc are planning a conference at Loughborough in September that could be a shout.

[Arboraeration]

We have had a busy few weeks with both Root Radar surveys and Airspade investigation works, and a combination of both. I will be trying to keep this post updated as and when with results that are interesting or unusual.

 

Below are a few images from a recent Root Radar Survey that was completed. The tree in question, a sycamore on the edge of a small wooded area with an existing tarmac driveway running along the left had side of the tree. from the results you can clearly see where the roots enter the driveway they immediately branch into a mass of much smaller and fibrous roots.