Hi Peter K,
The occasional use of a ‘non-airfield’ ATOM site as a waypoint at an appropriate height above ground level is unlikely to cause major disruption or disturbance. I fully appreciate your concerns, however, about potential nuisance to neighbours which could be caused by pilots deliberately using such sites (especially in domestic premises) as waypoints on a regular basis, especially at low level - and this should certainly be discouraged except where used at an appropriate altitude in accordance with the terms of the ANO.
In reality, however, I suspect that this practice is relatively rare, and there is certainly
NO advantage to be achieved by flying close to known ATOM sites in an attempt to generate or improve your reported radiation pattern. In fact, exactly the opposite principle applies!
If you were to set up a
linear route directly overhead a series of ATOM stations all in a straight line, the resulting polar diagram would (assuming no other in-range stations and that your antennas have clear coverage all round with no significant obscuration) simply show coverage in a straight line in your 12 and 6 o'clock as you approach and then fly away from each station, but nothing whatsoever either side of the fore/aft line. Similarly, flying a perfect circle
around a
single ATOM station would (in theory) produce a report along a single bearing from the Aircraft, (3, or 9 o’clock depending on direction of orbit), with maximum range equivalent to the radius of the circle around the ATOM antenna.
If users want to see the maximum coverage from their aircraft, they need to fly ‘past’ as many ATOM stations as practicable,
whilst keeping as FAR away from each as will still achieve a report from as many points as possible around their aircraft. Failure to do this will simply produce a diagram showing coverage at relatively short range - or nothing at all if you are
outside reception range from all of the stations. To achieve maximum exposure, the route should ideally also be flown in both directions, to expose both sides of your aircraft to the receiving stations along your route. In practice, however, simply flying a decent length route
through an area with multiple ground stations will normally ensure a fairly accurate and realistic range / obscuration report from Vector, the accuracy of which will build up and improve over time (assuming fairly regular flights).
I have, for example, just re-checked the coverage from my own flexwing (405A14) using the Vector Tool on the PilotAware website after last weekend’s flight to and from Popham (from East Fortune - east of Edinburgh). The polar diagrams for each separate transmission mode - in my case PilotAware, Flarm and ADSB - have been created from a combination of reports from previous flights (since 8th April) plus those from the 60 to 70+ separate ATOM stations ‘passed’ during each of last weekend’s flights to and from Popham (I haven’t flown since). The high number of stations reporting and the significantly varying bearing and range from each, of course, helps to maximise reliability in the resulting polar diagrams (though accurate reports can also be obtained from significantly less stations).
For anyone who isn’t aware of the Vector analysis tool, you can look at my results (or those for your own aircraft) by inserting the relevant information in the Vector analysis tool available via the following link....
https://www.pilotaware.com/analysis/vectorHope this helps clarify the situation...
Best Regards
Peter R