James Derrick's Diary Comments

Diary Comments added by James Derrick

Post When Comment
Reflections on 10 years of a changing Open Source Map over 4 years ago

Crikey - thanks for your kind words one and all!

As for survey images, it depends…

Mapilliary is useful for general survey images using a forward-facing phone camera when cycling or driving, but I still use a separate Garmin Oregon 750 camera for specific details.

For example, an older phone running Mapilliary continuously captured lots of useful images on a survey earlier today with minimal effort, but with a fixed forward view, it could not see a street name sign high up on a building wall 90deg to the road.

When photographing random details, a camera phone produces great images, but the GPS fix can be very poor when first extracted from a pocket. On the other hand, a dedicated GPSr gives a much better geo-location and runs for hours on AA cells, but the camera can be poor in low light.

So, everything is a trade off, but I tend to use Garmin GPSr most of the time as they have secure handlebar mounts, and complain less about heavy rain than I do! :-)

Photographs: A Contrast in Attitudes about 5 years ago

There’s one thing that stands out from all of Alex’s interesting posts - that of being a calm ambassador for OSM.

Any field mapper taking the time to gather detailed information by stopping and taking notes will sooner or later be greeted with the cry, “What do you think you’re doing?”. The key is to smile and calmly explain that you’re a volunteer surveyor for a global community project - not always easy with M* Angry breathing down your neck.

Humans are inquisitive species, with an eye for the unusual. What makes us map, also makes us question strangers. I’ve managed to turn a Neighbourhood Watch person from shouting loud questions into shaking my hand for volunteering, but unlike Alex, I’ve never been invited in to view the deeds for the surrounding land and discuss the history of the copse on the hill!

Happy Mapping, and please keep telling us about your finds.

New bike over 5 years ago

If I see you when surveying on my own green Brompton, I’ll definitely wave! :-)

Top tip - on a 6-speed check the bolts/ nuts holding the plastic derailleur arm are tight. Mine fell off after 6 months and caused great confusion in the dark.

I’m guessing you’ve probably used several cycle routing tools, but just in case…

I Ask for a #3 Buzzcut & This is What I Got! almost 6 years ago

Sadly, I remember when my head was landuse=forest, and tried to ignore as it changed to natural=scrub. Eventually, I succumbed to asking my barber for a tracktype=grade2, but fear ending up with a head of natural=bare_rock! :-)

BTW - your historical notes make interesting reading, and the tales of field mapping are all too familiar. I once encountered Mr Angry when out house number mapping, but after 15mins patient chat and a leaflet, he shook my hand and thanked us all for the project. Really didn’t see that coming!

TTFN, James

UK ITO! OSM Analysis has new road comparison data from OS Locator over 6 years ago

Hi Phil,

ITO! have a registration system for all their tools, and offer OSM Mapper (area change tracking) and OSM Analysis for free. I’ve had an account for years, but the direct link is:

ITO registration page - free

Details of ITO! tools - scroll down to OSM Mapper / Analysis

After that, data for each county is available in table (good for tracking), or slippy map (cyan = 100%) forms. Data imports from OSM can take about 3 days from edit to import. Note with the new OS Locater data, all of the stats are positive numbers, whereas usually you see negative values as areas are surveyed. I tend to manually compile a survey sheet with names and map extracts and head out into the field.

There is also a slippy map transparent overlay available in JOSM which shows the area of a diff which can be useful for looking at an area you are surveying.

I find it interesting spotting the areas with active mappers as they return to 100% agreement within weeks - e.g. the North West Wales, London, and Mappa Mercia areas quickly go cyan.



OS Locator update 201411 over 7 years ago

Hi Robert,

Thanks for the hard work behind this tool!

I find a combination of both the ITO Analysis tool and your Musical Chairs tool invaluable to keep my local area up to date.

Blyth Valley, Wansbeck, Castle Morpeth, Alnwick and North Tyneside are all getting back to 100% with your help and physical surveys to amend or to mark with not:name tags.

The ITO tools give a good numerical analysis by county area (UK Percentage Complete 98.00%), and an overlay which can be used directly in JOSM for comparison with OSM data and Bing imagery.

Your Musical Chairs tool is useful as it explains the data and logic behind a match in the sidebar, and is updated much more reguarly. I also appreciate the time you’ve taken to explain your algorithm, and extra features like the RSS feed which I intend to experiment with.

If the RSS feed can list diffs within a bounding box, could the processing produce a GPX file with the centroids of the non-green issues? I guess some areas could produce a very large query, but something directly loadable into a survey GPS would give paperless To Do list.

Thanks for your efforts.

Updating Sisters, Oregon over 11 years ago

Hi prathbun, and welcome to OSM!
Please be careful with the sources you use - Yahoo! and Bing have given a specific license to OSM to use their imagery, however Google has not and should _not_ be used. Doing so could pollute the open status of OSM and prevent re-use of the resulting map.
There's lots of information in the Wiki, and don't be put off by the legal bits. Pick a nice sunny day and get the GPS out yourself - it's amazing how many mistakes you'll find in so-called professional maps!

Mapping improvements made possible by [[Bing]] over 11 years ago

The talk mailing list included the announcement of an aerial image age viewer which uses the Bing API to display (presumably copyright) dates as an overlay to the images.

Unfortunately I must have been out when the camera flew over my house so dating the image by the colour of my car is not possible. Other features suggest the imagery is at the new end of my local quoted date range of 2004-08 - 2009-10.

New GPS iBlue 747 about 14 years ago

If you can live without a keyboard (useful for direct entry of street names when surveying), a N800 or 770 works well. If you can stretch to the N800, the additional CPU runs [[Maemo mapper]] very smoothly, and give a good mapping workflow (see for details).

From general comments, although the N810 has a GPS built in, an external BT device will give much better performance. For the best accuracy, try attaching your BT GPS to the shoulder strap of a backpack using rubber bands. This works well with a hydration pack for longer trips.

GPS logging on the Grand Union Canal about 14 years ago

Thanks Skywave - I'd seen the tailored map rendering for Cyclists, but not this one for canals. Looks like there is some very useful canal mapping going on.

I have seen other canal mapping sites, but none with the Creative Commons license for data: is commercial has excellent data but looks to be going commercial. It is based on Google Maps making it hard to run locally, although the WWW server module may be portable.