[HOT] Starting on JOSM

althio althio althio.forum at gmail.com
Wed Jan 14 21:56:41 UTC 2015

Hi Andrew, welcome to HOT and our mailing list!

> Worldview-2 ... name given is Digital Global - is this one and the same.

Yes. "The imagery [...] is from Digital Globe’s WorldView-2 satellite
taken on February 20, 2014."
This gets confusing when sometimes we refer to the provider and
sometimes to the satellite.

The imagery handling is quite complicated and has been modified over
time in this particular project.
So you picked a tough one for a starter but brace yourself and follow us!
Everything related to the imagery is detailed for this project in the
very first tab "Description".

For your convenience I copy here two sets of explanation regarding the
imagery instructions.
[from a previous thread with close topic at:

>>> 1. Start editing a task.
>>> 2. Load the Bing imagery (now 2013 images). (In JOSM do not use the alignment database plugin settings, they are no long needed for Bing imagery)
>>> 3. Make sure some buildings and roads are mapped correctly using the Bing imagery. Move or map some new ones to match Bing.
>>> 4. Then load the WorldView imagery (2014 imagery).
>>> 5. Background align the WorldView imagery to match what you just mapped in using the Bing imagery if needed.
>>> 6. Carry on mapping using the WorldView imagery after you have aligned it or checked its alignment.

>> As a summary of what Blake explained, you should use both imageries for project #591.
>> 1. First use Bing as a reference for alignment and do the first pass with most of the mapping;
>> 2. Second use Worldview - to be aligned on Bing - as it is more recent. Use it for an update pass mapping (it should be a few more or less buildings mostly).

With this in mind, let me come back to your questions.

> When I converted to JOSM as loaded, on one
> occasion I moved the bling image to co-incide with my plotted items, and
> adjusted the placing of these areas.  Are both of these actions valid?

In this project, Bing imagery is the common reference for alignment so
you should not move it.
I think michael63 helped you already with your square.
Do not try to align on GPS traces even if you can find one, as we are
interested in homogeneity.
Everyone aligned to Bing is more useful.

>> if you are not sure about the nature of an object do not place any questions in the name tag, use the note tag for this purpose

The note tag is well suited indeed for a remark concerning tagging.
Another common practice is fixme=* for instance "fixme=confirm if
school and add name" or "fixme=confirm if farmland".
These "fixme" tags really stands out with the map-style Humanitarian
that can be loaded in JOSM.
Many experienced HOT mappers and validators use this style.

Thanks everyone and keep going!

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