Thermal imaging its here to stay

[Yorkshireman]

should that not have been ' HERE' not ' hear'

 

sorry to be picky

[BatiArb]

should that not have been ' HERE' not ' hear'

 

sorry to be picky

 

 

Yes, sorry a different wavelength and another vibration

 

 

 

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[BatiArb]

I know this may be a bit of an ask but i believe last year (some time shortly after the southwest woodland show as thats where i saw you) you did a demo for a london council and jim mead was there from gristwood and toms (another one who is still yet to be won over i believe). I was told he was there with the picus to compare results, just wondering if they both complimented each other in the fact of giving similar results or if one showed findings the other did not?

 

Ben,

 

The following is a section from the e-mail exchange with Jim Mead regarding the demonstration you speak of.

 

Firstly I was disappointed to have such a blindingly obvious tree to look at. However, this has been a bit of a common problem, which is perhaps in some way due to a lack of understanding of where thermal tree assessment truly fit in. The assessment methodology uses observations of effective heat flow through trees to evaluate the proportion of functional wood and using TTMS software processing the reactive growth ability of the tree can be calculated.

 

Where trees have lost over 80% functional wood their ability to maintain a stable temperature will be severely compromised. Such trees will appear distinctly different from others of similar age and maturity so they are quickly spotted within a population survey.

 

The ash tree that we both looked at in the allotments in Enfield was just such a tree, where the internal dysfunction exceeded 80%. This was also in combination with some root issues that compromised the trees functional abilities even further, as a result the tree was in a condition where it could not maintain an even temperature and therefore had very little reactive growth capacity.

 

With consideration to your thoughts about posting a comparison between PICUS and thermal imaging it is my opinion that the two assessment tools are not comparable, because they are looking at different things. It would be a little like expecting to compare and ultrasound scan of a human body with an x-ray (not an ideal comparison but I think it illustrates the point). The two bits of equipment are looking at different things.

 

I believe that we need to consider how we use tree assessment tools and make more comparisons to how modern medical physicians use different scanning devises to assess our physiological condition. It is all about gaining more information about as many different aspects of a body’s function, in order to further inform a management decision about treatment. A physician will progressively ask for more scans to be completed depending on the results of others and how clear the information is.

 

When it comes to the cascade of assessments methods we have for trees I would suggest that the following order should be considered:

 

• Visual Tree Assessment by an Arborist

• Acoustic hammer (Elison style)

• Thermal Imaging to observe functional heat flow

• PICUS / TreeTronic / Radar

• Resistograph / DDD / core sampling

 

The above list is ordered with a view to:

 

• Surveyor expertise

• Speed of application (therefore cost)

• Requirement for visual evidence

• Invasiveness of equipment

 

The following paragraphs are from Jim’s response to the above:

 

Please be assured that, I am fully aware of the different applications of the two systems, and I appreciate the scientific implications of Thermal Imaging, and that it has potential as a valuable tool in our industry.

 

I am genuinely keen to see thermal imaging prove its efficacy as a tool for assessing the functional capabilities of trees under stress, and enabling us all to make better judgments on their potential for recovery, and or their response to treatment.

 

The choice of tree was nothing to do with myself and I knew from the outset, that the PICUS would produce results, perhaps more impressive to the lay person on such a subject tree and I am keen to be able to demonstrate to my colleagues and anybody else that's interested, that both systems do have value in Arb, and I agree with your order of application.

 

I would really appreciate being able to use your response, along with your report on the tree in Enfield, as I feel that both, together with my report, would put things in perspective, and may hopefully allow more people to understand the uses of thermal imaging over ultra-sound.

 

I trust the above is sufficient to answer you question.

 

 

 

 

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[Marcus B-T]

Getting back to the strictly scientific. There is one point that none of you have realised and that is that the system has the ultimate in auditable data.

 

If someone takes a thermal image and makes a claim about it, even if they have not subscribed to TTMS, you can take their image and run it through TTMS to analyse it. There are some real caveats with this of course, one being that they don't lie about the time and date they took it, but there are ways of even estimating this from angle of shaddow etc. Also a good TI image is almost as good as a photo in terms of being able to tell which tree it is from. Now that is transparity!

 

It means that it an LA is presented with an image as evedence for a planning application or TPO apeal. The LA can analyse the image independently using the software for themselves.

[Marcus B-T]

Ben,

 

The following is a section from the e-mail exchange with Jim Mead regarding the demonstration you speak of.

 

 

When it comes to the cascade of assessments methods we have for trees I would suggest that the following order should be considered:

 

• Visual Tree Assessment by an Arborist

• Acoustic hammer (Elison style)

• Thermal Imaging to observe functional heat flow

• PICUS / TreeTronic / Radar

• Resistograph / DDD / core sampling

 

The above list is ordered with a view to:

 

• Surveyor expertise

• Speed of application (therefore cost)

• Requirement for visual evidence

• Invasiveness of equipment

 

I Would like to propose the following amendment to the above.

 

VTA

Acoustic hammer

Thermal Image

Evaluation of tree height and dbh followed by canopy density and degree of sheltering if necessary

Picus etc

Invasive inspection

 

We have all the inforamtion we need to evaluate the relationship between potential wind load and potential failure, whether you use my system or one of the other systems so why not use it?

 

At the end of it all it is about using the tools available, so why not use them?

When you look at it critically, none of these methodologies are that expensive compared to the cost replacing a mature tree.

[Bundle 2]

"When you look at it critically, none of these methodologies are that expensive compared to the cost replacing a mature tree. "

 

You surely cannot be suggesting that the costs on either side of that equation are borne , and so shared by, the same party?.......

Perhaps an untimely query given the scientific bent to the discussion so far. Caveats and proprietal issues, either intellectual or otherwise, are of interest to those who may hold some interest in employing the technology in the very least. Perhaps the rest of us also?

[Amelanchier]

Marcus, what is the extent of the predictive capacites of TI/TTMS? I can see the function of comparison with a normal population but does it allow the user to test a hypothesis about possible causes of dysfunction? Would the user be able to walk up to a tree, identify some kind of symptom (tip dieback for example) and predict the result of the TI based on the possible causal agent (perhaps root damage)? What level of distinction can be achieved between causes that affect similar parts of the tree?

 

Often we are presented with images that have been translated/decoded after the fact and I wonder if there are any reasonable consistent correlations that could be tested up front.

[Marcus B-T]

The answer to both of the last two postings is sort of the same (the science bit not the cost bit will need to explain that later).

 

It is a question of the time line in the production process of the software. The first phase of the investigation is in essence a decoding process. An understanding of three processes:

 

How the environment affects the T max (you'll have to refer to my recent paper for this).

 

How the surface temnperature is altered relative to Tmax by dysfunction and decay.

 

But then thow the 3D jigsaw of the cahnge in temperature relates to certain symptoms, disorders, pests, types of decay etc, etc.

 

This is a long process of matching changes in temperature to causes.

 

This took about 4 years but is still an ongoing process as we learn more about new insect pests and all sorts of other things and will actually never stop.

 

We now have a robust software to calibrate the images, and thes images can then be analysed to identify where the critcal changes in tree functional wood are located. These tell you what is going on in the trees. If there is gross dysfunction at thye base, you know you have a root/rootplate problem. If it is at a branch union then that is where the problem is. I am of course talking in a simplistic way. Two principles are used the cahnges in T against Tmax but also the T distribution, these tell you about the amount of dysfunction but also the type of dysfunction e.g. is it a canker or maybe decay or then again dry wood.

 

This can be acheived because the speed of the technology allows you to collate large data bases.

 

Realy we are so far down the line with development of the technology, that IP doesn't worry me too much, there are some things that need to be retained, but I am happy to talk about most issues these days.

 

Be warned though that thermodynamics is a tricky subject I have been accused by one perosn of hinding the truth about how the system works. The fact of it is that although the mechanism of heat movement is quite simple and elegant, the physics behind it is complex. Having said that physics follws rules which cannot be broken so it is hard to lie with physics. If the tree is warm it iswarm if the tree is cold it is cold. The trick is to understand how warm it should be and why it should be at that temperature.

[Marcus B-T]

To answer Tony's question. Because some of the work shown has been historically old, it appears that we found the symptoms and then matched the thermal images. This is true because we were in that phase of development, but that was 3-4 years ago. This data was used to build the software. We now have a system that collects surface temperature data in a rigorous way, and this is used to establish changes in the way the tree moves heat around. This relates directly to the quality of tissues that allow this process to happen (basically wood with water in it). The conformation that this system works is that time and again the diagnosis and prognosis matches what was ultimately found to be true. It is true and fair to say that in the early days (4 years ago)the diagnoses and prognoses were occasionally inacurate, but this is part of the steep learning curve. It's a double edged sword, you stick your head above the parapet to have agood look but you also risk having your head blown off. I would like to say however that no trees were needlessly felled as the reslut of a thermal maging survey from me, even in the early days because I was careful always to advocate an invasive inspect just in case. I know there are rummours out there that I had this tree or that tree condemned when it was unecessary. The answer is not by me. There were condemned trees we used as tests and there was two occasions were I said "no the tree just needs to be monitored" and they cut it down any way. So it may seem that we find the probelm and then say it's like this following thermal imaging, but this is very old news and not what happens these days.

[Marcus B-T]

The other part of Tony's question is harder to answer. If the symptom is well developed then the cause can be easily determined. If the symptom is not well developed then it cannot be distiguised from other casuses. These are not visual symptoms by the way they are thermal syptoms I am talking about. This is true of methods though. So what we constsntly try to do is two things,

 

The first is to reduce the amount of noise that might obscure early symptoms that could identify the cause. The other is to constantly improve the description of each symptom sinsce this will allow us to better distnguish between symptoms and make earlier diagnoses. This is important becasue it allows treatment of the casues earlie and allow better management of the trees.

 

The issue here is that we have a great deal of data on some symptoms (e.g. K dusta on Beech) others we have less data on. However becasue we are constant collecting data we know more and more each day.