Meet our Alumni: Stephen Middleton

 

Stephen Middleton, one of the graduates of our Radar Masters programme, kindly agreed to be interviewed for the website:

 

Tell us a bit about yourself:

Stephen Middleton
Stephen Middleton

I grew up in Johannesburg and matriculated from St Benedict’s College in Johannesburg.

Thereafter, I obtained a BSc in Electrical Engineering from the University of Cape Town, and then went on to complete the M Eng, specialising in Radar and Electronic Defence. This included completing a variety of radar orientated courses including clutter modelling and analysis, target tracking, radar signal processing and radar imaging.

The topic of my thesis, which was supervised by Prof Mike Inggs, was “Target tracking in the range-Doppler space”.

I am currently based in Cape Town and am working at Von Seidels, an intellectual property law firm in Century City, Cape Town.

 

Can you tell us a bit more about your research at the time?

CFAR output with ghosting to illustrate target tracks
CFAR output with ghosting to illustrate target tracks

My project report was directed at target tracking in the range-Doppler space for commensal radars. Commensal radars make use of transmitters of opportunity to detect, locate and track targets in a manner that is non-detrimental to these transmitters.

The target detections are displayed on amplitude-range-Doppler plots and follow curved trajectories with time. In the case of FM band commensal radars, these detections are subject to low and fluctuating range resolution, making them difficult to follow visually.

This complication can be alleviated by tracking the targets in the range-Doppler space.

My project compared the Kalman, polynomial and recursive Gauss-Newton tracking filters for this purpose by using simulated and real data. The filter performance was evaluated on: tracking errors, computational load, data association statistics and real data tracking. All three filters were found to perform well, however the recursive Gauss-Newton filter tracked the most targets in the real data, achieved low errors and was the most efficient in terms of computational load.

Filter tracks of the two targets
Filter tracks of the two targets

I also conducted some research on Doppler-only tracking. One paper I co-authored investigated target tracking using Doppler only, observed from multiple receivers in a multi-static configuration. The tracking filter selected for the study was the recursive Gauss-Newton filter based on the Levenberg-Marquardt method.

FM Band Commensal Radar (radar that uses another system’s EM emissions) produces a Range versus Doppler plot, where the Doppler resolution is very precise due to the long integration time, but range resolution is at best poor due to the narrow broadcast channel bandwidth.

Thus, tracking that relies mostly on Doppler seemed the most sensible for this type of radar.

(You can read the Abstract of Stephen’s MEng Dissertation here – and also download a PDF of it.)

 

What benefit did you derive from the Radar Masters programme?

The programme exposed me to some of the leading researchers in the field. Through various courses, the programme touched on but a few of many aspects of radar and illustrated the complexity of modern radar systems. I gained valuable skills including conducting research, presenting findings, writing research reports and so on. The course strengthened my analytical and reasoning skills.

 

What did you find the most enjoyable?

The academic lifestyle was, of course, enjoyable. Being a part of a research group, with regular group meetings to discuss projects and latest findings was also great. I found the courses both interesting and challenging.

 

What did you find the most challenging about the course?

Some of the courses, the clutter modelling and analysis course in particular, were challenging.

 

What is your current area of interest or research?

I am currently training to qualify as a patent attorney. I spend much of my time researching, studying, understanding and describing new inventions. This presents great versatility in that each week you can be dealing with a completely different technology. This, in combination with dealing with cutting-edge technology on a daily basis, means that there is little room for boredom and monotony.

 

What are your goals for the future?

Simply to enjoy life.

 

What advice do you have for your fellow students?

For students at studying under the Radar Masters programme, to participate in the group as much as possible, to make use of the opportunities that present themselves, and most of all, to enjoy it.

 

I believe that you visited Antarctica during your Masters. Can you tell us a bit about that?

Stephen in Antarctica
Stephen in Antarctica

Yes, I did go to Antarctica during my Masters. I went as a technical assistant for the South African National Space Agency (SANSA) from December 2011 to March 2012.  I assisted with the maintenance of the radar down there, helped to resupply the base for the next year – and shovelled a lot of snow!

We travelled down on the SA Agulhas (the last trip it made to the continent before being retired). It took about three weeks to reach the base – with a few days spent completely stuck in ice – and about ten days back. We were on the continent for about 6 weeks.

The highlight of the trip was the uniqueness of the experience. It is something that few have ever experienced and something I will unlikely get to experience again. The continent still has a pristine feel to it, which adds to the experience.

We worked very hard, but had a lot of fun doing it.  I would recommend it to anyone.

Practically it is probably a once-in-a-lifetime experience; however, if the circumstances allowed, I would undoubtedly go back!

 

Thank you very much for the interview, Stephen. We wish you all the best for the future.

 

 

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