Since we began using the Tree Radar Unit for undertaking root radar surveys, we regularly come across the same similar questions from our clients. In this blog post we will aim to address some of these common questions in greater detail.
How accurate is the unit and how can you verify this?
We have conducted several verification exercises with the unit, both for our own satisfaction and to prove the results of root surveys for LPA’s. Because we use the 900Mhz antenna we find our results are incredibly accurate. Below are a few root radar scan results, displayed in the B-Scan analysis mode with the air spade trial pit locations marked in red and a photo of the air spade trial pit with exposed roots.
Can you scan through reinforced concrete?
We can scan through reinforced concrete, the TRU™ does pick up the reinforcing bars in the concrete however you can also see where the concrete ends and soil/sub-base begins. When undertaking the initial data analysis, we are able to add an “ignore zone” to the area of reinforcing within the concrete. This means the depths of all remaining root points etc are retained, however any markers that are flagged within this zone are not included within the outputs.
What happens if there are underground services?
The same way that reinforcing bars show up on the survey underground services can also be picked up. Because of the different properties between the base soil and metal or plastic utilities lines they show up as very bright markers on the analysis. In the same way as the concrete these can then be ignored when undertaking the analysis.
What outputs and data can you produce after scanning?
The standard outputs that we produce in our reports are Root Density Maps, these show the amount of roots detected within a 1m square. Root point maps, these show in individual root points as detected. Virtual line scans – These take an imaginary slice through the soil with all of the root points marked at their depths and lengths along the scan line. 2D root morphology maps, these maps use the trees location, the root data points that have been collected and some very clever computer software to plot the likely locations of the roots between the points. The 2D morphology maps can be coloured to show detections within a pre-set depth range as well as relative root diameter. The depths are incredibly useful for projects where ground level changes are being proposed. Finally, we tabulate the detections per scan line and the average detections per meter. If required we can also show percentages of roots per depth range as well.
