# 2022 03 16: [PICC](https://geoportail.wallonie.be/catalogue/b795de68-726c-4bdf-a62a-a42686aa5b6f.html) meeting

###### tags: `meetings with externals`

* **Nathalie Stephenne**: geomatics;
Geomatics works on geoportail & she works on data acquisition (including PICC);
50 people: topographs on the ground, photogramometers, administration
Nathalie works on remote sensing, landuse, qualigeo: e.g. with ULG analysis of PICC quality (available onlin!), documentation program for the diverse ways PICC takes shape

* **Sophie Petit**: ISEP, who works on qualigeo. From Navteq, ULG

* **Julien Minet**: at ChampsLibres, geo company. OSM contributor in Wallonia and community organizer.

* **Joost Schouppe**

## Introduction

* osmbe introduction
* OSM is a crowd, OSMbe is a face to the crowd
* [e-mail] as a single point of contact
* supporting volunteers to do their own thing
* taking the lead on some projects to fill in the gaps
* an Activity of Open Knowledge Belgium
* a Local Chapter of the OpenStreetMap Foundation

Building import: all the software written by Glenn, but with lots of input & organizational support from others, supported by OSMbe

* general principles of our "import"
* not "as fast as possible", but "slowly create the best possible dataset of buildings" (we're ambitious)
* OSM is an integrated datamodel: every building needs to fit into existing roads, landuse, POI, addresses, ... > most buildings will be touched manually before upload to OSM
* several year process to get to full coverage
* adding "external REF" (i.e. PICC object ID) to the building, so we can detect change easily (+ combined with geometrical change detection; mostly experimental)

Mappers are motivated by seeing correct data. This often extends to "external datasets", i.e. PICC. Many of us want to correct PICC as well. OSMbe also believes in governement data, especially for the fundamentals.

## Improving source data

### Systematic errors that we know of now
* Glenn has noticed **systematic errors** in PICC data:
* double versions of buildings
* the export query of "PICC+history" to "current PICC" depends on correct data. Sometimes, people make changes that should change an ID but it doesn't > hence duplicated buildings in "current PICC"
* possible causes mentioned by Nathalie: NGI buildings or export errors
* other causes of overlaps
* it seems like during digitization, the validation process is imperfect


Suggestions
- API access to our database > **Joost to ask Glenn to share examples and API access**
- bulk export of such cases

### Small errors that we notice as we map

* should we / how to report "**small errors**" (this building is gone, there are buildings missing, the building is drawn wrong; also address issues perhaps?)
* email, webform, ... > not needed at this time. But useful to see if we detect more mistakes as the PICC processes detect. PICC will share a map
* PICC is 5 years old on average, so missing/razed buildings is to be expected
* different processes in design (landuse / photogrammetry) to improve this, but not implemented yet.
* PICC has "field precision" (measured, streetside) or "image precision"

* Examples:
* very thin polygons stuck to main buildings, eg, building 5 and 12 on https://geoportail.wallonie.be/walonmap#BBOX=229095.79643014056,229198.65340668784,63825.27371593261,63874.42016839218
* small gaps between buildings: https://geoportail.wallonie.be/walonmap#BBOX=227737.26095076444,227840.11792731172,60811.70517906694,60860.85163152651 (in the center)

* how to detect the discrepancies (between PICC and OSM)?
* manually when the mappers integrate PICC
* by runnning comparison between integrated PICC buildings and OSM vs PICC buildings

## what PICC can do for us

* find people in their network who like to help, or can help find people who like to help
* communicate about the import in their newsletter/social media
* automated download service (> now registration + link via e-mail; also problemativ for Road Completion)

## Follow-up

- Julien to speak at PICC meeting (April 26th)
- Glenn to give data about systematic errors
- Joost & Jonathan to meet with Nathalie about Road Completion feedback
- Joost to look into PICC minor objects as a possible source of a MapComplete Notes project: e.g. benches (banc public), post boxes (Boîte postale), Borne incendie, Eolienne, Parcmètre, Poubelle, Fontaine ([full list](https://geoportail.wallonie.be/files/documents/WT_vNom_FINAL_24082017.pdf))

# Import flow

* start with an empty/partially mapped area

* load all the PICC buildings

* load OSM buildings

* keep only buildings that don't exist identically within OSM

* copy to JOSM
* validate validate validate