OpenStreetMap

Mungewell's Diary Comments

Diary Comments added by Mungewell

Post When Comment
Let's Fix Canada! about 12 years ago

401 - Unauthorized

Count me in on the fixing... PM me if you need to set up an account.
Mungewell.

vehicle tracking and road mapping over 12 years ago

One way to relieve the concerns about privacy on the raw data might be to pair adjacent points (so that there is still some direction/speed relationship which is useful in 'seeing' road structures), but otherwise randomize/zero out all other data.

Just to get some idea of how we can improve the data, how do you currently use Google maps (live position display, etc) and why is it lacking??

Where in the world are you (or rather the cars)?
Simon.

XC Ski Trail Map over 12 years ago

So is it possible to render differently depending on locale?

XC Ski Trail Map over 12 years ago

here...
http://osm.virtuelle-loipe.de/loipemap/?zoom=15&lat=49.66724&lon=-114.60483&layers=B000TT

XC Ski Trail Map over 12 years ago

Hi,
I've mapping out my local trails here:

There seems to be a contention between the difficulty colouration, we seem to use green for 'easy' (where you use blue) and blue for 'intermediate' (you use red).

http://www.crowsnestguide.com/allisonwonderlands/allisonmap.html

Cheers,
Simon

Northern Nigeria almost 13 years ago

I would ask the 'supervisor' to introduce you to a few of the drivers, and explain to them what it is all about. Show them a few maps of Nigeria verse other places and say that they can put 'it' on the map.

Most importantly explain how to turn the GPS on/off, I assume that their first impression is that you want to snoop on them. If they buy into the project that would be a great 'win' for OSM.

Yes, bribes (or 'tokens of appreciation') will work well too... ;-)

merge multiple files mergemultiple.pl almost 13 years ago

If you want to merge/extract or other mess with OSM files you can also use Osmosis...
http://wiki.openstreetmap.org/wiki/Osmosis

Position accuracy revised about 13 years ago

and.... when doing your stats you probably want to consider the horizontal plane seperately from the vertical. Elevation accuracy is weaker and will be approaching 2x the error of that for lat/long.

I believe that it is also 'valid procedure' to eliminate outlying data points from your data.

I'll stop typing now... ;-)
Simon.

Position accuracy revised about 13 years ago

Oh, you'll need a recent almanac file:
http://www.navcen.uscg.gov/GPS/almanacs.htm

Simon.

Position accuracy revised about 13 years ago

As RichardB points out the constellation repeats on an approximately daily basis, but your specific location can affect the performance significantly.

In general you want to have a good sky view, with a fair number of satellites overhead. You can find out the orbits and plan the best time for your 'survey' with a tool such as:
http://www.sokkiagps.com/support/s_planning.php

Another factor would be obstructions around your horizon, which could block signals or cause multipath. The rotation of the receiver/antenna may have effect too.

Did you know you can actually get raw measurements out the Garmins (http://artico.lma.fi.upm.es/numerico/miembros/antonio/async/node3.html), but doing this you could post process the data to find out whether the accuracy is down to the antenna/RF frontend or the positional processing of the micro.

Add in a local reference station and you should be able to get really (for a cheap unit) accurate....
Cheers,
Simon

East Hendred, Oxfordshire pretty well complete. about 13 years ago

Good Job. I did some time at the Rutherford Lab (south side of the Harwell site).

Being build on a old airfield the driveway (Fermi Ave on the map) was a bit of a cycle on windy days... ;-)
Mungewell.

Gzip for compressing planets about 13 years ago

oh I should add... you did recompile the compressors with optimisation for your machine, didn't you?

Gzip for compressing planets about 13 years ago

Interesting.... there's another compressor you could try 'LZO' which is intended to be fast on the decompress side. After all the planets are a compress once, decompress many scheme.

Most of these compression algorithms spend some time computing the best 'dictionary' to use. Since the planets contain pretty much the same data is it possible to force a pre-defined 'dictionary' into the compressor to speed it up?

Henley-on-Thames, Oxfordshire about 13 years ago

Looking really good.....

You might want to check the one-way stuff down by Mill Meadows though (unless you guys have started driving on the right).

Mungewell.

Hi, new member over 13 years ago

Hi Bobby,
Yes you can download/use/display maps for your project providing you meet the reqirements of the CC-SA license (basically putting 'maps CC-SA by openstreetmap.org' in or next to image).

Depending on what you want included you can download graphics from the 'export' tab, or download the map data and render the image to your liking.

There are some 'directions' websites and applications. If you require this to work in an offline mode, I suggest you look at Gosmore (http://wiki.openstreetmap.org/wiki/Gosmore).

Cheers,
Mungewell.

Comin along nicely over 13 years ago

Here's to putting ourselves on the Map!!

Good job,
Mungewell.

Clarification on what I'm looking for in terms of audio mapping over 13 years ago

link:
http://wiki.openstreetmap.org/wiki/Talk:Audio_mapping#Many_Short_Audio_Recordings

Clarification on what I'm looking for in terms of audio mapping over 13 years ago

I wrote this up and put on the Audio Mapping discussion page, if you can confirm that it works I'll promote it to the main page.

Cheers,
Mungewell.

Clarification on what I'm looking for in terms of audio mapping over 13 years ago

Whoops that GPX file didn't show all the tags... must have been stripped rather than escaped. :-(

Regarding the accuracy of the timestamps, the recordings might be made on a system (laptop?) with NTP hooked into the GPS receiver's 1PPS output. They could be very accurate.

Munge.

Clarification on what I'm looking for in terms of audio mapping over 13 years ago

Whilst you are waiting for JOSM to be improved....

--
$ cat strip_times.awk
{
if (first_time == 0)
{
# aiming at something like 2007-12-09T14:44:25Z
print strftime("%FT%T%Z", $1);
first_time = $1;
}

print strftime("%M:%S", $1 - first_time), $2;
}

$ find . -name '*.wav' -exec stat --format='%Z %n' {} \; | sort -n | awk -F ' ' -f strip_times.awk > events.txt

$ cat events.txt
2009-03-04T11:54:26MST
00:00 ./sample1.wav
00:04 ./sample2.wav
00:08 ./sample4.wav
00:11 ./sample3.wav
--

This should be passed to GPS event sync, which will produce a GPX output something like
--


14.0764
00:00 ./sample1.wav


16.4797
00:04 ./sample2.wav


18.4023
00:08 ./sample4.wav


15.0377
00:11 ./sample3.wav


15.0377
00:11 ./sample3.wav

--

If I remember correctly JOSM will play the audio contained in waypoints if the 'name' marker is replaced with 'link'.

Have fun,
Mungewell.