OpenStreetMap
Some of the areas have been mapped out remotely using satellite views, however on the ground things are somewhat different. Having done a walk around Gravesend today, quite a few road have missed, roads put in where there are none. The main problem is that shadows on the image causes errors to made.
Seems a shame that someone has taken a lot of time and effort to map out ways from
an image, only for then someone, me in this particular case, to rework lots of areas.
Another problem I have noticed is that the some of the imagery is quite old, some
I have seen is at least two years out of date.
So take care when using satellite views for mapping, try to use other sources as well if that is at all possible.
Discussion
Kommentar frå TimSC_Data_CC0_To_Andy_Allan, 1 april 2008 kl. 16:06
Hi netman55,
I was the someone who traced Gravesend. On your point on it being a shame to "rework lots of areas", people seem to be assuming that perfection should achievable first time or indeed at all. Neither are true. The map will always be a work in progress since the world changes continually.
When Galileo GNSS is available, the whole of OSM will need to be updated because of the improved accuracy available. They does not mean OSM is a waste of time before Galileo!
Anyway, I hope the tracing is of some assistance even if it contains errors. It is my preferred way of mapping and in some environments it is more accurate than GPS (or seems to be...).
TimSC
Kommentar frå daveemtb, 2 april 2008 kl. 12:04
I have done quite a bit of Yahoo tracing in the past, and would say that it really isn't a shame if you can correct traced areas - it's great! Tracing is done with the full expectation that the data will be incomplete and contain mistakes as you can't see what's going on under trees and lots of the Yahoo images are taken when shadows are very long, which makes interpreting them accurately very difficult.
The reason people like myself and TimSC are still tracing is that we believe it's better to have mostly accurate data than no data, and that it will save time for people like yourself who survey the area properly if the barebones are there already, even if it means you delete and redo areas. It should be clear from the lack of road names that surveying is still needed.
Kommentar frå daveemtb, 2 april 2008 kl. 12:05
Also, for a parallel, compare stub articles on wikipedia.
Kommentar frå amapanda ᚛ᚐᚋᚐᚅᚇᚐ᚜ 🏳️🌈, 2 april 2008 kl. 17:36
I'm an entusiastic tracer. But mostly I trace forgein cities I've been to once to twice, like Dar Es Salaam or Livingstone. I think it's great, because it lets you literally put these places on the map.