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Meet the team: Mark Greaves

11 Apr 2019
Ordnance Survey
Behind the scenes
GeodesyGeodeticGNSSGPSmeet the teamNational GridOS Net

Continuing our series to introduce you to the hard-working individuals within OS and showcase the wide variety of work we do, meet Mark Greaves. Mark has been with us for over 30 years and is definitely a fountain of knowledge here at OS! Here, he tells us more about how he keeps OS Net running…

Mark Greaves
Mark Greaves

How long have you worked for OS?

I have been at OS over 32 years and within this time held differing roles. I started as a Field Surveyor for 7 years, I then spent 1 year doing a HND in Surveying, 3 years as a Geodetic Surveyor, 1 year studying for an MSc in Engineering Surveying & Geodesy and 17 years as Geodetic Analyst.

How long have you been in your current role?

I have been a Lead Consultant for Geodesy for almost 4 years.

Can you describe your working day?

My days can vary greatly depending on what projects I am involved in. Aside from the obvious such as emails and meetings, I am in the team that supports the operation of the OS Net network.

I also occasionally receive geodetic enquires from the public from social media or through our customer contact centre ranging from simply “this trig pillar is damaged” or “can I move a benchmark on my house?” to complex “how does the OSTN15 transformation work?”.

What are you working on right now?

Right now, I am preparing an installation of a new version of the complex software we use to compute highly accurate coordinates from OS Net data. Additionally, I am taking part in some international consultancy work for OS as well as finishing an article on the OS Net receiver update and “future GNSS” for ‘Geomatics World’ magazine (the magazine of the RICS geomatics division). 

Next up, I will be planning the update to the OS Net data flowline required to handle all the new data streams from our recently upgraded receivers. 

What is your favourite part of your job?

I really enjoy the variety of the work and the fact that there is usually some kind of puzzle to solve. For example, I recently spent a few days crunching some numbers/formulae to derive an algorithm that generates the rotation between our National Grid projection and that used with WGS84 and the global “Web Mercator” projection (e.g. as used on Internet mapping services) at any point in GB. This was for the digital product development team. 

What is your OS highlight?

I have been lucky enough to travel to most of Europe and occasionally to the USA to represent OS and GB at geodesy conferences. More recently, international work for OS has taken me to the Philippines, Namibia and Guyana. 

I also enjoy the responsibility of computing the OSTN transformations that are used every day by our surveyors and many external surveyors. Without this, they wouldn’t be able to relate their GNSS surveyed data back to National Grid. 

In terms of moments that have made me think ‘I can’t believe I am getting paid for this’, I am lucky to have a few to pick from. I once spent an afternoon on a beautiful, deserted beach near RAF Kinloss in northern Scotland whilst surveying ground control points for an air survey. We had a white cross painted on an old antitank block as an air target and it was the perfect place to sit. 

Surveying in the Gaza Strip and West Bank was definitely a highpoint, especially as I was made to feel very welcome by the farmers whos land some of the survey control points were on – they even offered me fresh yoghurt and pots of tea!  

During the GPS survey of remote trig pillars for the OSTN transformation data, we flew around the Scottish Highlands by helicopter and I was dropped off for a few hours at a lonely pillar on the small island of Raasay (between Skye and the mainland) – it was stunning! 

What are you excited to work on (or continue working on) in the future?

The continued development of OS Net, especially preparing it for using the newer GNSS constellations BeiDou (China) and Galileo (Europe). Additionally, I am excited to be involved in future geodetic policy for OS and GB. This will include consultation on potentially changing the National Grid we have had for over 80 years to one more directly compatible with GNSS positioning.

Mark’s insight supports many of the historical blogs such as trig pillars, benchmarks and theodolites.

Ordnance Survey
By Ordnance Survey
Press Office

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