Tree Radar

A consulting Arborist must be trained to a suitable level (usually Diploma level or higher) and have sufficient experience within the industry (usually a minimum of 5 years). A consulting Arborist can advise on a broad range of issues pertaining to trees and their management.

There are numerous reasons for requirement of an Arborist report. Most often, it's because a Council has requested one as part of the submission for a permit application. Typically, if building or excavation is proposed to take place in close proximity to established trees, Council will want to know

The above ground part of a tree depends on the root system for anchorage, absorption of water and mineral nutrients, the storage of energy reserves and the synthesis of certain organic compounds. Given the physical size of trees one can then appreciate that the size of a root system that can perform all these tasks is considerable. Tree roots therefore extend past the edge of its canopy for considerable distances. This distance is dependant on the surrounding environmental conditions and/or physical barriers. A tree's root system is also (by and large) confined to the top 1000mm of soil with a large percentage in the top 600mm.

TRU™ (Tree Radar Unit) is a single system which can be used to scan trunks to quantify decay and scan soil to detect and produce maps of a trees subsurface structural root density. The system utilizes ground-penetrating radar (GPR) and represents a novel application of GPR applied to arboriculture.

GPR is a mature technology and has been used for sub-surface investigations over 20 years. GPR's main uses have included concrete inspection (establishing concrete integrity and re-enforcement), asphalt roadway thickness, bridge structural integrity, buried utilities and buried historical sites.

TRU™ is a unique application of GPR for tree trunk and root inspection. A patent was issued in 2003.

Yes. For trunk scans, an antenna is moved over the bark surface which is no more harmful to the trunk than rubbing your hand on it. There is no need to hammer nails or drill holes into the trunk.

For root scans, the antenna is placed in a special Teflon-impregnated tub which slides along the ground.

Setup involves removing the field computer and antenna from their cases, connecting them with the control cable, and recalling the appropriate setup file stored in the computer's memory. This is done in a matter of minutes.

Each 360-degree circumferential trunk scan requires the time it takes you to walk around the tree, about 15 to 20 seconds. A complete trunk scan, usually at four to six elevations, takes about 20 minutes including setup.

If access to the trunk or root bed is obstructed due to physical constraints or large cavities, etc., sector scans, which are scans over a portion of the area, can be performed.

Scanning over bumps, protrusions, and small cavities will cause a temporary loss of data which is not a problem because of the hundreds of readings being automatically recorded throughout a scan. Some hardwoods, such as London Planes, have large nodules throughout their trunks that make scanning difficult. In these cases, sector scans conducted between the nodules, are the best approach.

The extent of the decay column is shown by the multi-elevation scans, and the amount of remaining solid wood (RSW) is shown by both the cross-sectional image and the plot of RSW around the entire circumference for each elevation. If decay is found, the location and extent of the decay pocket, along with the amount of Remaining Sound Wood (RSW) can be used by a certified arborist to determine if the tree has sufficient structural integrity or if there is sufficient risk to merit a recommendation for removal. The presence of decay, sometimes even extensive decay, does not necessarily mean the tree needs to be removed.

An elevation of 2 ft (60 cm) above the base can usually be scanned. Depending on the curvature (flare) of the base, an elevation of 1 ft (30 cm) can sometimes be scanned. The point mode of data collection is the main "virtual drill" procedure for recording data at the base level.

Yes, either in an Elevated Work Platform (cherry-picker) or by a competent tree climber.

Two ways. The easiest, and most common, way is to use the mobile scanning cart. If access is limited, such as scanning in a narrow strip of ground between a tree and sidewalk or between rows of plants attaching the antenna to an extendable handle works best.

The calibration setup required for root scanning takes about 20 minutes. Following setup, each scan line, whether linear or circumferential, usually takes about 2 minutes.

Yes. GPR can penetrate ground covers such as concrete, asphalt, paving plates and brick. The TRU system automatically calibrates itself to "look through" the hardscape and penetrate to the roots below.

The maximum penetration depth using the (900MHZ) antenna is 1m in an average soil, which is well below the depth at which most structural roots are found.

A root diameter of 1 cm is the smallest root that can be detected.

Yes. Buried utilities - metal pipes, air-filled or liquid-filled pvc pipes, electrical lines - are easily detected and their location and depth are recorded.

No. Three radar reflectivity features of buried utilities distinguish them from roots: (1) their reflected amplitudes are significantly larger than roots, (2) they are located at known depths (determined by local building codes) and (3) they are usually straight and at constant depths.

Yes, but only momentarily. A rock, which is usually a good reflector, produces a "root-like" reflected signal whenever it is encountered. However, rocks, unlike roots, do not persist from scan line to scan line, so they can be identified and ignored when the final map is produced.

Very. The three components - field computer, scanning antenna and control cable - can be carried in a backpack or in two carrying cases. This allows TRU™ to be used at any height accessible to a competent tree climber.

Yes. Tests conducted for the U.S. Federal Communications Commission show the instrument to be ten times safer than your cell phone.