Geographical Information Systems V2


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Using Sat Nav and GPS in a geographical context

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Geographical Information Systems V2

  1. 1. Geographical Information Systems GPS and Sat Nav Garmin and Tom Tom
  2. 2. A walk in the hills • The plan was to meet with the mountaineering club on a Wednesday evening and go Rock Climbing. • I needed to find where they were climbing, get to the roadside parking and then walk up to the crag. • I started with the website – West Cumbria Mountaineering Club, they also have a Ning
  3. 3. This is the meet that interested me – Wallowbarrow crag, Duddon, Newfield Inn, Seathwaite.
  4. 4. Sat Nav • The Satellite Navigation works by touching the screen and entering a place, postcode or address; we tried Duddon, Newfield Inn and then Seathwaite [Cumbria]. • The Sat Nav calculated the route and then started giving instructions
  5. 5. The readout from the GPS on the windscreen Next turning 0.25 miles Total journey time 47 mins Speed = Stationary Arrival Time - 1758 Distance 21.6 miles
  6. 6. Problems occurred ‘en route’ Two diversions were passed and some care needs to be taken if it directs you down a closed road. There is a facility for finding alternatives and avoiding particular roads but this is where some of the problems with large lorries on small tracks and narrow bridges have occurred. It is worth checking signposts also as you travel.
  7. 7. The Sat Nav was directing us onto the A595 but ahead traffic flows were quite heavy for West Cumbria. We decided to turn right thorough Beckermet ignoring the instructions and travelling parallel to the main road.
  8. 8. Why heavy flows? The Sellafield Nuclear Power station ahead is the main employer in the area and at twenty past five the traffic leaving the site was quite heavy. The Sat Nav continuously tried to send us left back to the road but we persevered and were soon through the village and back on the A595 below the nuclear plant.
  9. 9. Back on the A595 - traffic
  10. 10. Normal rural delays • Although farmers milk twice daily you rarely get held up as their routine is known and most are happy to wait. The early morning milk is missed by most… • What delays do you experience on the way to work/school?
  11. 11. • Eventually we were through Eskdale and following good instructions up and over the open countryside of Birker Fell. • With few choices the Sat Nav makes good decisions
  12. 12. • We approach the village of Seathwaite and park The end is near beside the road
  13. 13. Tools available • I had grid reference for the crag so we took 1:25 000 map, Sat Nav and GPS with us. • Before starting the walked journey I turned on the GPS tracking so that it would follow the route.
  14. 14. Following • The Nav provided an arrow in relationship to the River Duddon but little else; a Lat and Long location can be extracted also • The hand held GPS gives you a much better current location and can record speed, location and in this case altitude. • It continually stores this data so that you can download it afterwards.
  15. 15. At the crag few climbers were to be seen so we Climbers? persevered on our walk looping around to return to the car about two hours later. Interesting features were tagged and added as way marks such as this rock
  16. 16. • The data was downloaded from the GPS to PC initially in the supplied Garmin Software. This Back at Base gives the shape of the journey Notice the variety of data recorded [line data from a series of points] and that some points have been and also the data as a table way marked.
  17. 17. This route was taken by minibus following a rivers collection day on the River Calder • A variety of different mapping packages support importing data from GPS units. This is 1:25 000 mapping from Anquet, the track is overwritten in green. Conversely ‘routes can be added on Choices your PC and then exported up to your unit for following.
  18. 18. Memory Map 1:50 • The whole walk with way marks was imported into memory map and laid over the 1:50 000 mapping • A profile or cross section was made of the route. As you follow this the cursor matches your position on the master map
  19. 19. Link to previous location Detail • Smaller detailed wanderings can be extracted using a Print Key Editor such as Print Key 2000. • These illustrate the route deviating along the former river meander and a newly established footpath not on our map [or the memory map] • The diagonal line is the fly in from the previously logged location - Langdale
  20. 20. Cross sections • The cross section of the map is linked to your track As you move the cursor across the profile it follows the track locating specific points. • Elevation data from the map can be compared with data from the GPS if it has barometric pressure assisting with identifying anomalies and changing pressure systems.
  21. 21. Fly through • Once a track is completed you can fly through the landscape, altering the vertical interval to exaggerate the landscape features. The journey can be paused to illustrate particular aspects.
  22. 22. Comparing Memory Map and the Garmin topological map • By generalising the cartographic detail on Ordnance Survey Very noisy maps the contours can be shown in clearer way. • This track was made on a trip up Easedale Tarn from Grasmere. • Note haw clear the hanging valley of Sour Milk Gill is shown.
  23. 23. Grasmere Detail • With simpler mapping it is often easier to identify geographical features; • Solifluction lobe shown poorly on 1:25 000 OS mapping • Footpath up Hanging valley indicates the position of the footpath. Relief shading also useful.
  24. 24. And finally at the end of the walk A quick check on line indicates that the Newfield Inn is CAMRA recommended and one of the Magnificent Seven, the best pubs in the area. We often ignore Google as a GIS, summary next
  25. 25. Review • Sat Nav and GPS are different devices, the latter has more geographical applications. • Sat Nav has to be used with some care especially when road conditions change. Good geographical knowledge helps with your decision making. • GPS can be used to collect a variety of good imformation but quality digital mapping is needed to make better sense. This can be point, line or area data. • Different mapping packages produce very different results. Tracklogs would not connect to the GPS so despite having this as our primary 1:50 000 maping it was of little use! • Google Earth, Census data and Aerial Images sources digitally all compliment Sat Nav and GPS.
  26. 26. Credits • Text and Images Mark OLLIS • Ever Faithful helper and standby camera operator Jacob • Creative Commons • • Made with the assistance of the beautiful Cumberland countryside.