[talk-ph] Cebu tracks.

[D Tucny]

2008/12/31 Jim Morgan <jim at datalude.com>

> Well thanks for the tip. Unfortunately I'd already finished my tracks the
> hard way by the time I read your post, so I'll have to use it next time.


Doing it the 'hard way' can often be better, especially if you have multiple
tracks, which is better too :) GPS devices aren't totally accurate an can be
affected by alsorts of things, buildings, mountains, trees, passing trucks
etc... So having multiple tracks and personal memory/photos/notes/other
input can allow you to draw a road or other feature more accurately than
using a single GPS track alone...


> Anyway, the national highway is now in place northbound from Cebu, and the
> tiny 1km by 2km island of Malapascua now probably has the most detailed
> cartographic representation anywhere on the internet!
>
> By the way, if you ever fancy a remote island getaway, its an awesome
> place.
>

Looks good :) Though, one note, if a path or road has no name, you don't
have to put one on :) i.e. a path with no name doesn't need to be given the
name 'Path', the highway type tells us it's a path :)


>
> In doing this, I've noticed that the major impediment to mapping in
> OpenStreetMap is the level of detail of satellite images on Yahoo. I could
> have filled in a lot more information if I was allowed to use the higher res
> images on Google Earth for eg, but that isn't possible of course. I think
> this will hold back our efforts in the Philippines unless we can think of
> some way around this.
>

Many parts of the world have been mapped to some pretty impressive levels of
detail with no usable aerial imagery by using 'oldskool' techniques of GPS +
note taking + photos... It does mean that someone needs to go everywhere,
but, that's the only way to get certain information, like the name,
anyway... Certain things are much easier with decent aerial imagery
though... e.g. It's very difficult to map buildings without aerial imagery,
you'd have to take accurate reference points and make measurements from them
to calculate position and shape of buildings which would take quite a bit of
time and effort, tracing from aerial imagery on the otherhand is quick and
easy...


>
> I don't think Yahoo is in a position to be lobbied to provide more coverage
> at the moment, and what with Jerry Yang's departure, the future of the
> company is looking unsure. I think we need to find another source of
> satellite imagery which we can use, or at least reduce the dependency on
> Yahoo.
>

Getting alternative aerial imagery would be good... but... it's expensive,
and for larger areas and and high detail levels, very very expensive...
Which probably explains why Yahoo doesn't have high detail coverage for the
whole world and why nobody else has come up with a global alternative...
OpenAerialMap, does have some coverage of some areas, but, it's a bit up in
the air at the moment with license issues and lack of leadership that seems
to be down to the person who started the project spreading his time a little
thin over too many things and the fact that OpenAerialMap is never going to
get a massive contributor base due to the difficulty in getting the imagery
that can feed into it... Alternatively, for smaller areas, there are a
number of people who have done things with model aircraft... Also probably
not very cheap, or easy, but, if you're already into model aircraft,
possibly something that could be looked into...

d
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