JOSM / OSM servers will limit the download of data, thus when I work on Grenoble for example which is highly built up, the maximum area I can download in one go is about 300m square.
All this means is that I must complete a number of downloads to download the town and merge the layers into one if I wish to use the OSM for a custom map - or just set JOSM to download to the same layer.

This is a chore but completely understandable given the amount of data this non commercial server must push backwards and forwards at any given time to the whole community.

I personally tell JOSM to upload in 100 segment chunks, thus a 1000 point upload will go up in 10 sequential uploads ( upload > Advanced tab ) , I have found this to be much more reliable than uploading in one go, especially with big change sets and or if I have inadvertently created conflicts which must be resolved
bri

hope that helps some

Just to back up previous posts and to explain. Open Street Map is just that, it is about making a OPen Source map that all can use, based on data that has been defined as Open Source by its contributors ( ie OSM editors such as yourself ).

Contributors ( OSM editors ) can use their own data ( GPS Traces, personal surveys of areas etc ) and use data that other suppliers have let us, including Yahoo Imagery and Bing.

The fact that the data starts as open source, means that the map remains open source for all users ( and you sign a license agreement with the website to confirm that you give your data as that ). No one wants to compromise OSM with data that even might belong to someone else ( Google etc ), explaining why the community gets very nervous when ( usually ) a new user suggests they have ( helpfully ) added data from a non open source.

Please keep up the good work and welcome to OSM, and keep us updated on your edits.
bri

Yep - all true - BING can be offset, ( I have pre built offsets for Kaduna ( northern Nigeria in Josm, backed up / confirmed by dozens of GPS traces taken over many days ).
Yes GPS can be off, and Garmins sometimes decide to offset themselves for a few minutes by several meters and then re correct themselves.
Really the trick is to have many GPS traces of the same primary highways, uploaded by different users, aggregated over periods of perhaps several years. In this way a fairly good average can be built up, and confirmed by Bing. At least with Bing, the offset will be reasonably constant over a certain area, so once you have an aggregate of GPS traces you can offset the Bing by a reasonable degree.

We should note that if you are using a GPS map derived from OSM, then GPS the user is navigating with will just as likely have a GPS offset, even if the map is 100% accurate, so I guess the word is always caution!

The map is probably about right, how good is ones receiver GPS ?This is possibly why many GPS units also offer the option of locking to map to 'correct' possible location errors.

More in my diary entry here - white space interference - interesting stuff..

@bri%20g/diary/13746

Just another thought, I was thinking that I only ever use batteries to power up my Garmin, but of course I, as all other mappers do, plug it in to the USB port every time I need to download data from it, and never had a problem. The 5V from a USB port is well regulated and extremely unlikely to be overvoltage, which brings suspision in your case,back to the car adaptor.

I have had three Garmins, the original etrex, the legend and now the legend HCX all bullet proof, dropped them, lost them, got them wet, had them hanging off my bicycle, fall off my bicycle ( many times ) all fine
I personally would check your car adaptor which probably cost 20 Euro, used to power up a 200 Euro GPS to deliver 5V via USB. A Small power spike etc from the 12V/5V lighter socket adaptor might be all it takes to destroy internal components.
Garmin UK sent me a free battery compartment cover once when I lost mine (dont ask how), they are good and no, I do not work for them.

Hi
I downloaded the last two sets of traces that you have uploaded - JOSM was happy with them no issues ( 20110630.gpx & 20110625.gpx ) so not sure what the problem with PL2 if any.

Your traces seem to be a little noisy ( possibly due to being in a built up area ) - and this part of Harvard Campus has excellent BING imagery which will always tend to have a better accuracy than GPS traces and more useful for absolute mapping purposes.

The Garmin Etrex units (depending on which one you have ) have a couple of options on how they store tracks.

The best setting for mappers is to set the units to cache your location every 1/2/5 seconds etc ( I personally cache on 1 second ) using a Garmin HCX Legend with a 2GB memory card. If you have an original Yellow Garmin Etrex, you will not have this option, and you are stuck with the Garmin caching technique, that when it detects that you have made a significant move from your last cached point, or are making a direction change. it is an efficient approach in terms of data storage, but can lead to rather untidy tracks especially when you are walking.

To Clean up GPX tracks before uploading can sometime be useful, especially if you have left the GPS unit on ( perhaps at home or work ) and you find a large cluster of noisy points etc. I usually drop my GPX tracks into JOSM and use the plugin EditGPX to tidy up a trace before upload. You can also merge a number of tracks down into one layer thus saving you multiple uploads of smaller GPX tracks.

You have highlighted a another problem - but I think that needs a new Diary entry
Good luck and enjoy making your traces - have a play with JOSM and some of the plugins, I am sure you will find them useful

The Streets and street names are in one way just the beginning of building the OSM map of a town or region. The map really becomes useful once the information about your community is added. For example addition of location of resources such as Banks, Shops, local facilities, Restaurants, Hotels, Petrol stations, Supermarkets, Libraries, Sports Facilities etc.

One can map a town from Bing in an hour, but that extra data can only really be provided by mappers on the ground such as yourself, so good luck and enjoy yourself and your mapping - and thank you for getting involved!

Might be useful comparing and contrasting the data from different sources - I have used the Cloudmade Garmin IMGs ( http://downloads.cloudmade.com/ )
and recently started using the custom maps found here ( http://garmin.openstreetmap.nl/ ) which are a little smaller and seem to have sightly friendlier rendering ( for my Garmin Legend HCX ).

I recently spen several weeks cycling in Spain - the OSM maps were great - but I still carried paper, as sometimes there is just too much detail in the electronic version, Zooming in and out all day - I also carried a compass - life saver, sometime you just want to head SOUTH! I always kept the HCX on, logging at 1 second intervals through the whole trip and later uploaded to OSM, some of the most accurate tracks I have generated I think - AA rechargeable batteries on the HCX lasted about 20 hours, recharging them in local cafes and bars ( I carried two sets ).

Good luck - enjoy spain

A very handy tool here for Garmins

http://garmin.openstreetmap.nl/

Yes - Very much enjoy the Sahara desert imagery : fake Steve just possibly?

Love it - agreed - no waste of time - what are computers for?

Great work - Africa needs much more mapping effort - keep up the good work - and YES please - link to the area of the map you are working with - bri

BING imagery does seem to have offsets to GPS Traces around the world. I have edited a number of places with BING but cross references with my own multiple GPS traces taken over multiple periods ( important for accuracy apparently, as it changes / shifts during the day )

JOSM does allow you to adjust the BING imagery with an XY offset. If you ask JOSM to download the GPS traces ( highly recommended ) you can check the imagery aligns with the GPS traces, if not I align the imagery to the average trace - assuming a main road is close by with intersections, allowing northing and southing to be checked.

Assuming there are multiple traces of the GPS on roads, assume that the average of these traces is pretty much about as accurate as we can get right now.

Not all GPS devices are the same, modern units are more sensitive ( Garmin etc ) than previous versions and generally more accurate - 3-5 meters with larger antennas than that possible to fit into a mobile prone thus generally more accurate ( more signal / less noise ).

You can check the date of the pictures in Bing imagery here

http://mvexel.dev.openstreetmap.org/bing/

Try Cloudmade -

http://downloads.cloudmade.com/asia/israel#downloads_breadcrumbs

I Added a button on the tool bar of my josm app with exactly this tag
(
highway=service
service=driveway
source=Bing
)
I have save loads of time - wave a look here to add the Oneclick buttons to JOSM - they are very useful if you are tagging a lot of roads

http://josm.openstreetmap.de/wiki/TaggingPresets

bri

Great to see some high detail, and 'good old fashioned ' walk the streets mapping being carried out in Brazil - Keep up the good work

bri

Also
GPSMID Convert OSM FILE to Java Midlet for Symbian ( works on my Nokia E51 )

http://gpsmid.sourceforge.net/

Josm has become increasingly powerful over the two years I have been using it. The new integration with BING is very good.

Great advice from !i! regarding reducing UI complexity, I have just two floating windows open, Properties and Layers, the rest are opened when needed.

One thing that has really improved my productivity on very repetitive work has been adding my own custom tagging buttons for basic things such as Residential, Unclassified, Tertiary roads and Buildings, with the extra tag of source=BING.

Take a look here
http://josm.openstreetmap.de/wiki/TaggingPresets

I took the original xml script from Dirk Stöcker - added my custom requirements for Residential / Unclassified Road etc ( with tag source=BING) and this has speeded me up no end.

Just as background I completed a lot of work around south Portugal over the Christmas period, as this has become available from BING to map, hence the need for the source tag

Hi Seth

Thank you for asking the community, before proceeding with a best guess. A good general rule in OSM is that if you do not know how to do something review and copy from best practice areas mapped such as in the US, UK or Germany where multiple mappers have worked and reviewed each others edits, so should be about right.

Rainer111 mentioned Merkator, JOSM is also very well developed, and once you start using a desktop editor ( as opposed to Potlatch ) you will not look back. The investment in effort to learn either of these very useful and stable tools is well worth the payback.

bri