ASOG Article of the Month - July 2020
ASOG Author: Gareth Davies ; Image: mypolice.gld.gov.au
With a growing effort to integrate drones in the public safety sector around the world, one of the hardest part for a public safety organization is what to think about or plan around when it comes to starting a drone program. Gareth Davies, based on his professional experiences, discuss what to think about when starting your drone program.
Drones, UAV, UAS call them what you will, seems they are here to stay. However, before I start and for clarity of terminologies within my article, I’m going to use the term Unmanned Aerial Platform (UAP). My rationale is that a helicopter is a Rotary platform, an aircraft is a fixed wing platform and a drone, UAV (unmanned airborne vehicle) or UAS (unmanned airborne system) are UAPs. O.K., enough of that.
So, from the position of an Air Support Unit (police, Fire dept. emergency service, a.k.a., ASU) or as an Operations Officer you have decided that there is something in all the hype regarding UAPs. So, where do you start or what you should think about before obtaining a UAP? Even though there are many technical things to think about, and from my experience, here are my top three things to contemplate.
Frequency
The labyrinth is the frequency. Frequency defines almost everything about a platform, i.e., from controlling the platform to sending imagery to the ground. When it comes to sending data to the ground, this is known as ‘downlinking’. Frequency defines how much data (data rate) you can transmit within the frequency. How much data defines the resolution you need for the task at hand. You do not need 4k resolution to determine a fire, however I submit it would be essential if you are going to put a bullet in someone or a hellfire missile though a windscreen.
Currently most video transmission systems operate in the 1.9 to 2.5 gigahertz range. The 2.4 range is by and large licence free which means you should not use them if you are in the Emergency service game or if you don’t want the press ‘looking’ in. Please check with your frequency allocation people when you wish to start operating (They will be chuffed you have asked. However, they will also know you are taking the whole business of frequency serious. This is a personal experience).
Power & Distance
Consider how far from platform transmit (TX) to receive (RX) site. This number or average number is critical because it defines the TX power requirement. Be careful here because blasting away on the TX site with a powerful transmitter that is often frequency and location restricted and for the most part bigger is not better, because, as you will read later, you will upset the wrong people.
Output power in watts defines the actual physical size and weight of your unit. This clearly will have a form fit issue with the platform.
And last but not least, the wattage of your eventual transmitter will have to be generated from the platform, so you UAP has to be ‘big’ enough provide sufficient power but having enough left over to fly and return.
Frequency Management
All ASU’s have a prime and backup frequency. It used to be that (in the UK anyway) these were ‘purchased’ for their exclusive use The Police take a very dim view of anyone caught using them.
DO NOT use a frequency that is not yours unless it has been allocated to you for specific period of time. Think ‘dim view’, police, Government officers and being “Upset.”
If you do use a frequency without authorization, you will probably get caught. Here’s a good story to reinforce the point. Since WWI when prevailing winds meant that there were only three ways across the channel for the Zeppelin’s the Military knew which path they were going to take because there was significant increase in ‘activity’ (voice and signal traffic) from one of the three stations. I would hazard a guess and suggest that GCHQ (UK’s listening centre, amongst other things) have become a tad more sophisticated since then. And that most countries will have followed suit.
Just as a tip, ask to ‘borrow’ (most transmitters are frequency agile) your local ASU’s backup frequency and run a number of ‘missions’ in parallel. Start collecting and collating data from these missions until you have sufficient to populate a matrix document. Then you will start to see which ‘service’ better suits the task at hand.
Operations
Clearly task, locations, mission specifics et al all affect mission operations but here are a few things from real life that I have found useful. They apply to drone operations just as they did in the real word
I was taught as a kid that when canoeing you always row against the current so that if you are tired and/or underestimate your ability you can always float back on the current to your starting point.
I hear next to nothing about air currents but obviously 15 mins with the prevailing wing and air current will take you farther that 15 mins against the same conditions so be wary.
Sorry to bore you again with Spacecraft control analogies, however…
I was controlling a telescope called ROSAT at the German Space Operations centre, Nr. Munich, with a ground station south of Munich, that had 7/8 passes of 7 to 8 minutes windows. This was our commanding and data collection time. These times were predicted (AOS, Acquisition of Signal and LOS, loss of Signal) so that the Ground station was ‘visible’ to ROSAT. We usually needed 5/6 passes to complete all commanding.
During an oversight that saw us still transmitting commands some 20 secs after official LOS, we were staggered to discover, during the next pass, that these commands had actually reached the Spacecraft. Over the next months we carefully ‘pushed’ the envelope to discover that for some reason ( jokingly said that we bounded commands of the weather station roof that is built into the rocks on the summit of Germany’s highest mountain, the Zugspitz, however I suspect a more technical and esoteric explanation would be ionosphere refection after AOS and LOS).
I tell this anecdote because the following year we had a requirement to send a massive file that breached the official single pass parameters and the fear was that by splitting up the commanding into 2 passes we would lose continuity and therefor the integrity of the file.
Imagine the surprise when the command team hit the command button 30 secs before AOS and we ran about 25 secs after LOS and the complete file was loaded.
Parameters
This will be short-and-sweet. Find out your complete mission critical kit parameters before your mission becomes mission critical. This might cost you a battery or two, but the rewards are real if a little further down the line.
Implementation
At some point the bean counters will ‘suggest’, because of budgetary considerations there will have to be a crossover between Rotary platform operations and a supplementary UAP.
Having been in international sales for 20 years I know that words alone will not suffice to convince an ASU that your drone can replace its helicopter. And neither should it. As I have just said it should be supplementary, so at some point you are going to have to run your UAP and rotary in parallel and compare the outcomes.
To do this you are going to have a regularity the Air Support Unit (ASU) boys can ‘see’.
In Summary
No matter what you call a Drone, the critical aspect of implementing or integrating this new kit of technology to your Air Support Unit is planning. When it comes to planning, there are many variables to consider. However, there’s always the top 3 or 5 things to consider, in this case, and in my professional opinion and experience, is Frequency Management, Operations, Parameters, and Implementation.
So, with that, Good ‘hunting’
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