Organised by Simon Ritchie.

Leatherhead Institute, Saturday 26th October 2024

£12 for the day, please buy a ticket here:  https://buytickets.at/merrrowinternetservicesltd/1418449(link is external)

Survey equipment using navigation satellites such as the Global Positioning System (GPS) has been around for over twenty years.  In the early days the equipment was expensive and only used by large organisations such as the Ordnance Survey.  Recently it's become much cheaper and easier to use.  Equipment that can tell you your position to within two or three centimetres is available off the shelf for about £300.  This one-day course combines hands-on experience of this low-budget technology, along with some of the theory behind it.  By the end, participants will be better able to choose what to equipment to buy and know how to use it.

On the face of it, the equipment is very easy to use.  Put it down anywhere with a view of the open sky, switch it on and a minute or so later it displays your position.  Job done!  The problems start when you try to interpret the numbers that it displays. 

Register from 9:30am, the day starts at 10am with some theory:

• How satellite positioning systems work.
• How much do they cost to buy and to run?
• Coordinate systems used (longitude, latitude and height, ECEF, the OS grid) and problems converting between them.
• Continental Drift, the problems it causes and some solutions.
• Configuring the equipment.
• Troubleshooting.

After a break for lunch (*) we will go to a suitable nearby location outdoors and use the equipment.

Continental drift is a problem for surveyors because modern equipment is accurate enough to reveal the effect, so it has to be accounted for.  The equipment gives you your position to within two or three centimetres.  The UK is drifting north-east at about 2.5 centimetres per year, along with the rest of the Eurasian tectonic plate.  If you measure a position on "solid ground", then within two years it will have shifted enough for the equipment to notice.

However, this creates an interesting project for schools, which is to measure and track continental drift over a school career.  This can be used to illustrate lessons in subjects including geology, mathematics, physics, chemistry, biology and ancient prehistory.

(*) Tea and coffee will be provided during the day but lunch is not provided.  The Leatherhead Institute is at the top of Leatherhead's High Street which has a thriving selection of cafes, restaurants and places to buy sandwiches.

The Leatherhead Institute:  https://www.leatherheadca.org.uk/.  The postcode is KT22 8AH.

Leatherhead is served by train from London Waterloo and London Victoria.  The Institute is five minutes walk from the station.  Buses run from Guildford, Kingston-upon-Thames and Dorking.  The nearest long-stay car park is on Station Road, postcode KT22 7AB.  For details see here(link is external).

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