The Great Newlands Trigonometrical Survey
Contents
Information
Created By: Jonny Huck
Currently Used By: Jonny Huck
Location: Newlands Valley (requires transport to Little Town)
Instructions
Get the group on a minibus and transport them to the car park at Little Town (£5 per day honesty box so cash required).
Give out the equipment (put each person in charge of something that they then have to bring back!) and set off along the path towards Newlands Valley.
About half way there, stop where you can see the white building with a large telegraph pole behind it and there is space amongst the bracken to set up a tripod. Give them a bit of chat about Triangulation, you can use the Principal Triangulation image from Wikipedia, and the Lancashire Triangulation map from the map library to help illustrate this. Show them how to:
- set up the tripod
- mount the automatic level (don't level the automatic level, as we are using it as a theodolite)
- use a mirror compass to get the direction to the telegraph pole
- set the automatic level using the compass
- use the OS Locate App to work out where they are (with a brief explanation of how GNSS receivers work), understand that they need to add a '3' and a '5' to the easting and northing values respectively
Walk them on to the foot bridge, and get them to work out where they are, including orientating the map. Explain about coordinates and how to locate points on the map (which has a 100m grid). While walking, you can chat about the industries that have affected the valley - mining (copper & lead; graphite in Borrowdale); sheep farming, biodiversity; tourism; reforestation on Skiddaw etc.
Explain the task (to plot the course of the stream. You can split them into two 'teams' if kit allows and there are enough students. Note that the students can only access the river bank on the East side, so tell them to map this, and to be careful around the large river cliff (go over the top on the path). They must have a clear plan, including how far should the staff(s) move each time? (100m = c. 60 double paces) and who is doing which job (operating the level, the staff, the app, plotting the result onto the map, etc.).
They should set up their 'base stations' each side of the spoil heap (they won’t be able to see each other) - the further apart the better. Success is basically directly proportional upon the area of the triangle so make sure that the baseline is nice and wide (at least the full width of the spoil tip)! Walk straight up the hill for the group south of the spoil heap and follow the path for the group to the north (it is extremely boggy in-between). Make sure that you are up there to make sure that they set up the level correctly - if they mess up the orientation, then they have no chance of success!
When they return, compare their effort to the real map; you can then have a discussion about accuracy, precision and uncertainty and how these things build up in field work, as well as about how well they worked as a team (invariably they will have set off before really agreeing on a proper plan). Then ask them to measure their river section (using compass string and grid squares) and lead into a discussion about the Coastline Paradox (the measured length is just a function of the scale of analysis, in this case, how big the gaps between readings were).
Leave 45 mins for packup, debrief (comparison & coastline paradox chat) and to walk back to the van.
Equipment
Students (per team, comprising two 'bases', one or two staffs and a controller):
- Mirror Compass x 2
- Surveying Staff x 1-2
- Automatic level & Tripod x 2
- Walkie Talkie (one each plus one for staff)
- Android mobile phone with waterproof case x 1-2 with the project app (to handle the triangulation maths) and the OS Locate app to get their location.
- Pencils
- A4 Clip board x 1
- Student Handout x 1
Staff require:
- Staff Handout x 1
- Principal Triangulation image from Wikipedia
- Lancashire Triangulation map (can just excerpt the triangulation bit)
