The document presents the experience of swisstopo at the EPFL-ETHZ Open Science Summer School 2022, focusing on the strategies and specifications for open government data (OGD) in Switzerland. It outlines the timeline of OGD strategies from 2014 to 2023, legal and financial considerations, and the implementation of the STAC (Spatiotemporal Asset Catalog) specifications for efficient geodata management. Additionally, it highlights technical solutions and the infrastructure supporting the federal spatial data system, along with its impact on various applications and services.

1. Open Government Geodata, Open
Standards, Open Software
The experience at swisstopo
EPFL - ETHZ Open Science Summer School 2022, 2022-06-28 Lausanne
Pasquale Di Donato – COGIS/swisstopo
Federal Office of Topography swisstopo
COSIG

2. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Agenda
• Definitions and context
• The STAC Specification
• The STAC API Specification
• The STAC API of the Federal Spatial Data Infrastructure
2

3. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Government Data, Open Government
Data
• Government Data: data produced, collected, managed,
processed and stored by public authorities to fulfil their legal
obligations
• Open Government Data: government data that can be freely
used, processed, analysed and transferred without any
significant legal, financial or technical restrictions
• Legal point of view: free (as in «free speech») terms of use
• Financial point of view: free (as in «free beer») use and
reuse
• Technical point of view: machine readability
3

4. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Open Government Data Strategy in
Switzerland
• The move towards “openness” of government data in
Switzerland has been fostered by:
• Open Government Data Strategy for Switzerland 2014 –
2018 (approved April 2014)
• Strategy for open government data in Switzerland 2019-
2023 (approved November 2018)
4

5. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
OGD Strategy 2014-2018
• opendata.swiss is developed as central portal for open
government data
• Metadata for geodata is harvested from geocat.ch, the
metadata catalogue of the Swiss geodata
• A report of the implementation of the strategy (published July
2018) has shown that:
• Despite being binding, the strategy was not perceived as
such by all stakeholders
• The differences in the implementation were still too great
• So many and different regulations on fees as a barrier for
the implementation
5

6. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
OGD Strategy 2019-2023
• «Open by default»:
• Data produced or commissioned by public authorities
should in principle be considered open government data,
provided no legal provision exists to the contrary
• Find a legal solution that would ensure at the same time:
• The free use and reuse of data
• The mitigation of any financial loss
6

7. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Legal and financial constraints
• Public authorities have to address legal and financial issues
before they can publish their data as open data
• E.g. swisstopo:
• Ordinance of the DDPS on the Fees of the Federal
Office of Topography (before March, 1th 2021): defines
for each dataset the fees that have to be paid
• The implementation of the OGD strategy results in an
estimated decline in swisstopo’s income of about 4-5
Million CHF/year
7

8. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
swisstopo goes open
• Under the impulsion of the «Strategy for open government
data in Switzerland 2019-2023» swisstopo decided early
2019 to initiate the process that would have allowed its data
to be published as open government data
• Legal as well as financial issues had to be addressed
8

9. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
swisstopo goes open
• The «Ordinance on Geoinformation» had to be adapted
(entry into force on March 1th 2021):
• Art. 2: introduces the concept of «open government data»
• Art. 28a: geodata (access authorisation level A) are made
accessible as «open government data» by means of
«geoservices»
• Art. 44: no fees are required for «open government data»
• The «Ordinance of the DDPS on the Fees of the Federal
Office of Topography» (entry into force on March 1th 2021)
has been substantially revised:
• No fees for service-based access to «open government
geodata»
• Fees for analog products, special services, misuse of the
geoservices
9

10. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
swisstopo goes open
• The shortfall of 4-5 Million CHF/year had to be approved by
the Parliament
• The new swisstopo’s budget was approved by the federal
chambers in December 2020
10

11. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Implementation
• Meanwhile, while waiting for changes in legislation and
budget approval, COGIS was charged with identifying a
technical solution for the implementation
• COGIS (a division of swisstopo) coordinates the activities of
the federal administration in the field of geoinformation and
with regard to establishing and developing a federal and a
national spatial data infrastructure
• COGIS develops and operates the federal spatial data
infrastructure (FSDI). Open standards and open software are
pillars
• The technical solution for the ODG had to be based on open
standards and open software and implemented in the general
context of the FSDI (so that other offices could profit of it)
11

12. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Implementation: the STAC
specification
• “The SpatioTemporal Asset Catalog (STAC) specification
provides a common structure for describing and cataloging
spatiotemporal assets”
• “A spatiotemporal asset is any file that represents information
about the earth captured in a certain space and time”
• The data model is based on the following concepts:
• Collection: is a set of metadata about a geospatial dataset
• Item: represents an atomic collection of inseparable data
and metadata. An Item serves as an index to Assets
• Asset: the actual geodata file
12

13. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Implementation: the STAC
specification
• The STAC data model has been mapped in the context of the
FSDI as follows:
• Collection: each dataset is described by a collection
• Item: datasets that can be downloaded as a complete
package, have at least one item, but can have more, one
for each version of the data made available. Tiled datasets
(e.g. national maps, orthophotos) have at least one item
per tile, but can have more, one for each version of a tile
• Asset: an item can reference several assets, one for each
configuration of the data in terms of spatial reference
system, format, etc.
13

14. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Implementation: the STAC API
specification
• The STAC API Specification specifies a RESTful API for
querying STAC resources. It is designed with a set of
endpoints for searching across collections and items
• A STAC API can be implemented in compliance with the
OGC (Open Geospatial Consortium) API Features
14

15. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
STAC Tools
• Server
• Client
• API
• CLI
• Data Creation
• Data Processing
• Visualisation
https://stacindex.org/ecosystem
15

16. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The STAC API of the Federal Spatial
Data Infrastructure
• The FSDI STAC API is a «file based» download service
implementing and extending the STAC and STAC API
specifications version 0.9
• Migration for version 1.0 is in the backlog
• All data files are stored in a S3 bucket
• All metadata (collections, items and assets descriptions) are
stored in a PostGIS database in order to implement the
query functionalities (e.g BBOX, datetime, intersect) of the
API
• Django and Django Rest Framework
• BSD-3-clause license
• Available on github: https://github.com/geoadmin/service-stac
16
https://www.geo.admin.ch/stac-api

17. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
Demo
• Landing Page
• List of Collections
• A single collection
• List of items
• A single item
• BBOX
• Datetime
17

18. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The STAC Browser of the Federal
Spatial Data Infrastructure
18
https://data.geo.admin.ch/browser/index.html#/

19. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The STAC Browser of the Federal
Spatial Data Infrastructure - Search
19
https://data.geo.admin.ch/browser/index.html#/search

20. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The FSDI STAC API on STAC Index
20
https://stacindex.org/catalogs/datageoadminch#/

21. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The FSDI STAC API in a more recent
STAC Browser
21
https://radiantearth.github.io/stac-browser/#/external/data.geo.admin.ch/api/stac/v0.9/

22. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
OGD via other FSDI services
• Web Map Tiling Services
• Web Mapping Services
• Vector Tiles Service
• … and more at api.geo.admin.ch
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23. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The impact of OGD
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24. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The impact of OGD - Integration in
global geoservices
24
ArcGIS Living Atlas
MapBox Satellite
Maptiler Imagery
…
https://www.esri.com/arcgis-blog/products/arcgis-living-atlas/imagery/high-
resolution-data-updates-to-living-atlas-world-elevation-layers-and-tools-june-
2021/
https://www.mapbox.com/blog/new-imagery-for-the-netherlands-and-
switzerland

25. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The impact of OGD - Outdoor Apps
25
https://www.imaginemag.ch/realitymaps-die-app-fuer-alpinisten-und-alle-die-es-werden-wollen/
https://info.skitourenguru.ch/index.php/swisstopo4guru

26. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The impact of OGD - User Apps
26
https://mesh-tiler.karavia.ch/#6.86517/45.83267

27. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS
The impact of OGD - Commercial reuse
27

28. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS 28

29. EPFL - ETHZ Open Science Summer School 2022
2022-06-28 Lausanne
Federal Office of Topography swisstopo
COGIS 29
… thanks for your attention