[Talk-GB] Mapping from a survey

[James Derrick]

On 13/05/2022 10:51, Mark Goodge wrote:
> I want to map something that's not yet visible on the aerial view, and 
> probably won't be for a while. I could do something which approximates 
> to the right positioning of the various ways that I'll need to add, 
> and then update them later when the imagery is available.

In the last 15 years, I've tried most techniques from voice recorders, 
Nokia cameras, pen and paper, walking papers, and even compass/ 
protractor for mast heights!

These days, my main mapping tasks are cycle survey of building sites 
every 3-6 months to collect new street geometries (GPX) and names (GoPro 
images).

A phone running an app to collect a GPSr location once a second into a 
GPX file and a camera with GPSr location tagging turned on is all you 
need. (Although I will admit to rather excessively going on cycle 
surveys with 4x GPSr devices - Garmin 550, Garmin 750, OSMand+ on an 
Android phone, and GoPro!)

If you are interested in different survey methods then can I suggest:

https://www.openstreetmap.org/user/James%20Derrick/diary/43039

https://wiki.openstreetmap.org/wiki/Pick_your_mapping_technique

Check out the animation of a GPX survey showing one point per second - 
new residential sites are the same as mapping 15 years ago - high-res 
imagery doesn't exist, unless you get out and collect it! :-)


IMHO geo-located automatic high-res images give the best balance of 
accuracy, effort on the ground, post-processing and information capture.

An old Android phone, a pound shop USB battery, and OSMand+ is more than 
enough to survey new estates with GPX location tracks. Adding images, 
the Mapillary app running on an old phone pointing forwards captures 
more detail, but a GoPro works in the rain for 3 hours if you have 
£200-400 to spend.

A GoPro time-lapse offers more than a regular GPX 1-point a second log 
as the geo-located 5MP high-res images are very clear. Recent cycle 
surveys have allowed not just newly built streets to be added, but also 
sometimes a complete set of address information down to individual 
buildings. Three visits to a friend yielded about 100 homes with full 
address data as the numbering plan is sane (1, 2, 3 or 1, 3, 5) and 
enough images showed door numbers to be sure of the pattern.

Happy Mapping,


James
-- 
James Derrick
     lists at jamesderrick.org, Cramlington, England
     I wouldn't be a volunteer if you paid me...
     https://www.openstreetmap.org/user/James%20Derrick