[Talk-ug] Import of Buildings in Districts Bordering DRC

Bert -Araali- Van Opstal bert.araali.afritastic at gmail.com
Tue Jul 14 06:55:23 UTC 2020


Thanks for the feedback Deogratias,

Appreciate a lot what you are doing and the approach.  This seems a well
managed project in the pipeline.  Keep on going !

One question, you state the Maxar imagery is again available in JOSM ? I
am running version 15553, about 1 year old, and it still doesn't load
Maxar.  Do we need to update to most recent ? What version are you
running with Maxar available ?

Greetings, Bert

On 14/07/2020 09:29, Deogratias Kiggudde wrote:
> Hello Bert,
>
> Thanks for your insightful feedback and comments about the process. 
>
>  1.  Regarding the offsets, you are right, the team will be updating
>     that section of the process so that mappers rely both on the
>     buildings and road features when making the offset to align features.
>  2. For the imagery, the team will be using a purchased updated maxar
>     Imagery. Maxar imagery is now back on JOSM and ID editor
>     (premium and standard). The imagery purchased covers the bordering
>     districts in Uganda as well as DRC and is of a 2019 date. The
>     import team will also be trained to use buildings under
>     construction and other features to determine the most recent
>     imagery. From our initial assessment, the imagery purchased is
>     newer than inbuilt maxar and bing imageries and clearer than the
>     Esri World Imagery.
>  3. Replacing geometry is definitely a tricky situation, the team
>     plans to use the conflation tool mainly for the buildings be able
>     to replace geometry and reduce on the number of deletions in the
>     process. Through this process, the tags already existing on a
>     building feature will be preserved and only new tags will be
>     added. The import team will also be trained to be able to align
>     prereferral features like gates and boundary walls but I do agree
>     that will be a sticky situation that I will discuss with the team
>     to see how we can navigate it smoothly
>  4.  Yes, we are counterparts in DRC are in touch with the UN Mappers
>     that are currently mapping in the areas of Ituri province. The
>     discussions on ways how we could combine forces as well as share
>     responsibilities are still ongoing but that's for highlighting
>     this situation.
>
> Thanks again Bert for the good comments I will be discussing to my
> team to make some of the edits you sighted as well as acquire more
> concrete information on our collaboration with the UN mappers and
> revert to you with more information.
>
> Best 
> Deogratius
> *Humanitarian OpenStreetMap Team *Project Manager, Uganda Email:
> kigguddedeogratias at hotosm.org
> <mailto:kigguddedeogratias at hotosm.org>Skype: deogratius kiggudde
> Twitter: @KigguddeDUG Mobile: +256 703 143 225
> http://donate.hotosm.org/
> *Using OpenStreetMap for Humanitarian Response & Economic Development*
> web <http://hotosm.org/> | twitter
> <https://twitter.com/hotosm> | facebook
> <https://www.facebook.com/hotosm> | donate <https://donate.hotosm.org/>
>
>
> On Thu, Jul 9, 2020 at 10:08 PM Bert -Araali- Van Opstal
> <bert.araali.afritastic at gmail.com
> <mailto:bert.araali.afritastic at gmail.com>> wrote:
>
>     Hello Deogratius,
>
>     First of all, great project, really looking forward to get going.
>
>     I went through both wiki pages, and overall very solid and
>     detailed approach.
>     I do have some concerns, points on which improvements could be made.
>
>     1) Offsets - in many previous HOT projects offsets were provided
>     by the project manager, which are easy to store and implement in
>     JOSM. Until November 2019 we could use the MAXAR imagery in JOSM
>     (still blocked ? only Maxar imagery in ID), and I used it a lot. 
>     My experience was that it has significant offsets in comparison
>     with other imagery layers, especially on hill sides you see a lot
>     of distortion.  This can even be seen in the offset of roofs in
>     regard to the ground level.  An important issue in correct
>     alignment of the imagery.
>     So when you state in the procedure that we should align the layers
>     by looking at the buildings this will not be correct.  On a tile
>     by tile basis you should align with features on ground level, most
>     convenient are roads.
>     Another way could be we have GSM tracks or reference points from
>     the field.  The project manager could make offsets available for
>     every tile using these field datasets or you could engage some
>     people in the field to get them.  Because even many of the
>     existing buildings could be misaligned.
>
>     2)  How to determine which data is the most recent.  The Maxar
>     imagery is dated. Other imagery layers on which existing buildings
>     are mapped is mostly not.  SO there is no clear reference of what
>     is most recent.  Comments and descriptions in changesets can
>     provide some information, as many existing mapping is done based
>     on field knowledge. So some improvement and more details could be
>     provided in the procedure on how to determine which is the most
>     recent and accurate data by referring and evaluating data in the
>     changesets.
>     Same applies to building relations when 3D mapping was done.  You
>     should provide some details there that in these cases only the
>     building outline should be replaced and other building:parts
>     should be updated.  There are not many but some are there because
>     I added them.  This is a very complicated task.
>
>     3) Replacing building geometry.  Will be a much more extensive
>     exercise as described.  Many areas are far more detailed then just
>     the buildings.  As you probably know many have the plots aligned
>     with landuse tags, other features as fences and gates are present
>     at many locations.  If you replace the geometry with the new
>     buildings all these "attached" features, some even sharing nodes
>     with the building, must be updated.  I have no experience with
>     geometry replacement so how will this work ?  If a misalignment is
>     seen all the features need to be aligned as a group.
>
>     4) Currently there are two UN mapping teams doing a lot of work in
>     these areas, in support of MONUSCO troops. One focuses on roads
>     and buildings, the other team on landuse.  How do we avoid
>     conflicts with those projects or get them involved ? They
>     contacted me several times so they are open for cooperation.
>
>
>     Greetings and success with the project.
>
>     Bert Araali
>
>     On 02/07/2020 17:46, Deogratias Kiggudde wrote:
>>     Hello community,The subject of this message is to inform the OSM
>>     community in Uganda of an import prepared by HOT [1] as part of a
>>     project to scale up the Missing Maps initiative, combining data
>>     extracted in a way automated and information collected in the
>>     field [2].In the Uganda , this import consists of more than 2
>>     million footprints of buildings located in the districts of
>>     Kisoro, Kanungu, Rubirizi, Kasese, Bundibugyo, Ntoroko, Bulisa
>>     Hoima, Kikuube, Nebbi, Zombo, Arua, Koboko, Maracha, Kiryandongo,
>>     Kamwenge, Kyegegwa and Insigiro. This data was extracted from
>>     high-resolution imagery provided by Maxar over the period 2015 to
>>     2019.
>>     A wiki page with details of the proposed import is available here:
>>     https://wiki.openstreetmap.org/wiki/FR:Import_B%C3%A2timents_Maxar-Ecopia_Est_RDC_%26_Ouest_Uganda <https://wiki.openstreetmap.org/wiki/FR:Import_B%C3%A2timents_Maxar-Ecopia_Est_RDC_%26_Ouest_Ouganda>
>>     A second page contains the practical details of the proposed
>>     methodologyto perform this import:
>>     https://wiki.openstreetmap.org/wiki/FR:Import_B%C3%A2timents_Maxar-Ecopia_Est_RDC_%26_Ouest_Ouganda/D%C3%A9roulez <https://wiki.openstreetmap.org/wiki/FR:Import_B%C3%A2timents_Maxar-Ecopia_Est_RDC_%26_Ouest_Ouganda/D%C3%A9roulement>
>>     Experienced OSM contributors who would be interested in
>>     participating inthis import will be welcome.
>>     A similar message regarding this import will also be shared on
>>     the OSM mailing list of DRC and the HOT mailing list to gather a
>>     maximumfeedback.
>>     Don't hesitate to share your comments, questions, or
>>     problemsrelated to this import before it begins.
>>     Best
>>     Deogratius
>>     [1] https://wiki.openstreetmap.org/wiki/Humanitarian_OSM_Team[2]
>>     https://www.hotosm.org/projects/leveraging-ml-generated-building-data-and-motorcycle-mapping-in-the-drc-and-uganda-to-enhance-humanitarian-response/
>>     *Humanitarian OpenStreetMap Team *Project Manager, Uganda Email:
>>     kigguddedeogratias at hotosm.org
>>     <mailto:kigguddedeogratias at hotosm.org>Skype: deogratius kiggudde
>>     Twitter: @KigguddeDUG Mobile: +256 703 143 225
>>     http://donate.hotosm.org/
>>     *Using OpenStreetMap for Humanitarian Response & Economic
>>     Development*
>>     web <http://hotosm.org/> | twitter
>>     <https://twitter.com/hotosm> | facebook
>>     <https://www.facebook.com/hotosm> | donate
>>     <https://donate.hotosm.org/>
>>
>>     _______________________________________________
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>
-- 
Ing. Bert Van Opstal Mobile: +256 782 304106 Email:
bert.araali.afritastic at gmail.com
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