Publication Date: 2021-11-29
Approval Date: 2021-11-18
Submission Date: 2021-08-13
Reference number of this document: OGC 21-055
Reference URL for this document: http://www.opengis.net/doc/PER/202107APISprintER
Category: OGC Public Engineering Report
Editor: Gobe Hobona, Joana Simoes
Title: July 2021 OGC API Code Sprint Summary Engineering Report
COPYRIGHT
Copyright © 2021 Open Geospatial Consortium. To obtain additional rights of use, visit http://www.opengeospatial.org/
WARNING
This document is not an OGC Standard. This document is an OGC Public Engineering Report created as a deliverable in an OGC Interoperability Initiative and is not an official position of the OGC membership. It is distributed for review and comment. It is subject to change without notice and may not be referred to as an OGC Standard. Further, any OGC Public Engineering Report should not be referenced as required or mandatory technology in procurements. However, the discussions in this document could very well lead to the definition of an OGC Standard.
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- 1. Subject
- 2. Executive Summary
- 3. References
- 4. Terms and definitions
- 5. Introduction
- 6. High-Level Architecture
- 7. Results
- 7.1. Augmented Reality Application
- 7.2. CubeWerx CubeSERV
- 7.3. ZOO Project
- 7.4. GeoServer
- 7.5. Ecere GNOSIS Map Server
- 7.6. Hexagon Geoprocessing Suite
- 7.7. QGIS MetaSearch Plugin
- 7.8. Mappings between ISO 19115-3 and OGC API - Records Queryables
- 7.9. OpenSearch Syndication Protocol
- 7.10. pycsw
- 7.11. pygeoapi
- 7.12. Other Outputs
- 8. Discussion
- 9. Conclusions
- Appendix A: Supporting Different Metadata Encodings in OGC API - Records
- Appendix B: Mappings from OGC API - Records Queryables to ISO 19115-3
- Appendix C: Revision History
- Appendix D: Bibliography
1. Subject
The subject of this Engineering Report (ER) is a virtual code sprint that was held from July 21st to July 23rd, 2021 to advance the development of the OGC API - Processes draft standard, OGC API - Records draft standard, and the OGC API – Coverages draft standard. An Application Programming Interface (API) is a standard set of documented and supported functions and procedures that expose the capabilities or data of an operating system, application or service to other applications (adapted from ISO/IEC TR 13066-2:2016).
2. Executive Summary
This Engineering Report (ER) summarizes the main achievements of the July 2021 OGC API Virtual Code Sprint, conducted from July 21st to July 23rd. The goal of the code sprint was to progress the development of the draft OGC API standards for Records, Coverages and Processes. The sprint served to accelerate development of candidate standards of the OGC APIs.
Specifically, the objectives of the code sprint were to:
-
Develop prototype implementations of OGC API – Processes
-
Develop prototype implementations of OGC API – Records
-
Develop prototype implementations of OGC API – Coverages
-
Test the prototype implementations
-
Provide feedback to the Editor about what worked and what did not work
-
Provide feedback about the specification document, especially what is missing from the document
Part of the motivation for holding the sprint was:
-
APIs are a popular, effective method for rapid software development
-
There is an increasing need for interoperability between Web APIs
-
The growing uptake of location within and outside of geospatial developer communities
The draft OGC API - Processes specification defines an interface that enables the execution of geospatial computing processes and the retrieval of metadata describing their purpose and functionality. Typically, these processes execute well-defined algorithms that ingest vector and/or coverage data to produce new datasets.
The draft OGC API - Records specification defines an interface that enables discovery and access to metadata records about resources such as features, coverages, tiles / maps, models, assets, services or widgets. The draft specification enables the discovery of geospatial resources by standardizing the way collections of descriptive information about the resources (metadata) are exposed and accessed.
The draft OGC API - Coverages specification defines an interface that enables access to coverages that are modeled according to the Coverage Implementation Schema (CIS) 1.1. Coverages are represented by some binary or ASCII serialization, specified by some data (encoding) format. Arguably the most popular type of coverage is that of a gridded coverage. Gridded coverages have a grid as their domain set describing the direct positions in multi-dimensional coordinate space, depending on the type of grid. Satellite imagery is typically modeled as a gridded coverage, for example.
The code sprint successfully met all of its objectives and achieved its goal of progressing the development of the OGC API - Processes draft standard, OGC API - Records draft standard, and the OGC API – Coverages draft standard. There were no issues found on the Processes API, which helped to validate the maturity and stability of the API. Discussion about the Records API helped to improve understanding of the potential relationship to other related specifications (e.g. STAC and ISO 19115). Issues raised relating to the Coverages API were focused around clarification, thereby identifying areas where the documentation could be improved. The sprint participants demonstrated that the OGC API pattern can effectively address the needs of communities that use, process and analyze geospatial data.
2.1. Document contributor contact points
All questions regarding this document should be directed to the editor or the contributors:
Contacts
Name | Organization | Role |
---|---|---|
Gobe Hobona |
OGC |
Editor |
Joana Simoes |
OGC |
Editor |
Adrian Akbari |
adrianakbari |
Contributor |
Adrian Cochrane |
OpenWork Ltd |
Contributor |
Amy Youmans |
AGC |
Contributor |
Andrea Aime |
GeoSolutions |
Contributor |
Angelos Tzotsos |
Open Source Geospatial Foundation |
Contributor |
Benjamin Pross |
52°North GmbH |
Contributor |
Bradford Dean |
Mohawk Council of Kahnawake |
Contributor |
Brian Hamlin |
Open Source Geospatial Foundation |
Contributor |
Byron Cochrane |
OpenWork Ltd |
Contributor |
Chris Holmes |
Planet |
Contributor |
Clemens Portele |
interactive instruments |
Contributor |
Colin Steinmann |
Ethar Inc |
Contributor |
Diego Caraffini |
Ecere co. |
Contributor |
Eike Hinderk Jürrens |
52°North Spatial Information Research GmbH |
Contributor |
Fabio Govoni |
MEEO |
Contributor |
Francesco Bartoli |
Geobeyond |
Contributor |
Gérald Fenoy |
GeoLabs |
Contributor |
Gladys Villegas |
Ghent University |
Contributor |
Iain Burnell |
Dstl |
Contributor |
Ingrid Lagares |
UFMG |
Contributor |
Jeff Harrison |
AGC |
Contributor |
Jerome St-Louis |
Ecere |
Contributor |
John Ferry |
Trenchant Analytics |
Contributor |
Mario Cavicchi |
MEEO |
Contributor |
Martin Pontius |
52°North Spatial Information Research GmbH |
Contributor |
Nazih Fino |
Global Nomad GIS Services |
Contributor |
Panagiotis Vretanos |
CubeWerx Inc. |
Contributor |
Patrick Dion |
Ecere Corporation |
Contributor |
Paul van Genuchten |
GeoCat BV |
Contributor |
Philippe Pinheiro |
LIST |
Contributor |
Richard Conway |
Telespazio UK Ltd |
Contributor |
Rob Emanuele |
Microsoft |
Contributor |
Roger Brackin |
Envitia |
Contributor |
Stephan Meißl |
EOX |
Contributor |
Steven McDaniel |
Hexagon Geospatial |
Contributor |
Tom Kralidis |
Meteorological Service of Canada |
Contributor |
2.2. Foreword
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The Open Geospatial Consortium shall not be held responsible for identifying any or all such patent rights.
Recipients of this document are requested to submit, with their comments, notification of any relevant patent claims or other intellectual property rights of which they may be aware that might be infringed by any implementation of the standard set forth in this document, and to provide supporting documentation.
3. References
The following normative documents are referenced in this document.
-
OGC: OGC 18-062, OGC API - Processes - Part 1: Core candidate standard
-
OGC: OGC 20-004, OGC API - Records - Part 1: Core candidate standard
-
OGC: OGC 19-087, OGC API - Coverages - Part 1: Core candidate standard
-
ISO 19115-1:2014, Geographic information — Metadata — Part 1: Fundamentals
-
IETF: RFC-7946 The GeoJSON Format (2016)
4. Terms and definitions
For the purposes of this report, the definitions specified in Clause 4 of the OWS Common Implementation Standard OGC 06-121r9 shall apply. In addition, the following terms and definitions apply.
- ● coordinate reference system
-
coordinate system that is related to the real world by a datum term name (source: ISO 19111)
- ● coverage
-
feature that acts as a function to return values from its range for any direct position within its spatiotemporal domain, as defined in OGC Abstract Topic 6
- ● record
-
atomic unit of information of a catalogue that is used to provide information about a particular resource
- ● OpenAPI Document
-
A document (or set of documents) that defines or describes an API. An OpenAPI definition uses and conforms to the OpenAPI Specification (https://www.openapis.org)
- ● Web API
-
API using an architectural style that is founded on the technologies of the Web [source: OGC API - Features - Part 1: Core]
Note
|
See Best Practice 24: Use Web Standards as the foundation of APIs (W3C Data on the Web Best Practices) for more detail. |
5. Introduction
This Engineering Report (ER) summarizes the main achievements of the July 2021 OGC API Virtual Code Sprint, conducted from July 21st to July 23rd. The sprint had been organized to advance the development of draft standards of OGC APIs for Records, Coverages and Processes. Sprint participants prototyped implementations of the draft standards, validating the requirements and providing feedback so that the draft standards could be improved.
An OGC Code Sprint is a collaborative and inclusive event driven by innovative and rapid programming with minimal process and organization constraints to support the development of new applications and open standards. OGC Code Sprints experiment with emerging ideas in the context of geospatial standards, help improve interoperability of existing standards by experimenting with new extensions or profiles, and are used for building proofs of concept for other OGC Innovation Program initiatives, or to support OGC Standards Program activities.
6. High-Level Architecture
6.1. High Level Overview
The code sprint was executed in support of the development of the draft OGC API - Records, OGC API - Processes and OGC API - Coverages standards. Implementations of these draft standards were deployed in participants' own infrastructure in order to build a solution with the architecture shown below in Figure 1.
As illustrated, the sprint architecture was designed with the view of enabling client applications to connect to different servers that implement OGC APIs. The servers were provisioned with metadata, implementations of algorithms for geospatial analysis, vector feature data, and coverages such as satellite imagery.
6.2. Candidate Standards
6.2.1. OGC API - Processes
The draft OGC API - Processes specification defines an interface that enables the execution of geospatial computing processes and the retrieval of metadata describing their purpose and functionality. Typically, these processes execute implementations of well-defined algorithms that ingest vector and/or coverage data to produce new datasets or analytical products.
6.2.2. OGC API - Records
The draft OGC API - Records specification defines an interface that enables discovery and access to metadata records about resources such as features, coverages, tiles / maps, models, assets, services or widgets. The draft specification enables the discovery of geospatial resources by standardizing the way collections of descriptive information about the resources (metadata) are exposed and accessed.
6.2.3. OGC API - Coverages
The draft OGC API - Coverages specification defines an interface that enables access to coverages that are modeled according to the Coverage Implementation Schema (CIS) 1.1. Coverages are represented by some binary or ASCII serialization, specified by some data (encoding) format. Arguably the most popular type of coverage is that of a gridded coverage. Gridded coverages have a grid as their domain set describing the direct positions in multi-dimensional coordinate space, depending on the type of grid. Satellite imagery is typically modeled as a gridded coverage, for example.
7. Results
Multiple organizations provided servers, API implementations, and capabilities during the event. The rest of this section describes each of the implementations.
7.1. Augmented Reality Application
Developers from Ethar Inc and Global Nomad took part in the code sprint, extending an Augmented Reality (AR) application that they are building for Testbed-17. The AR application, which runs on a smartphone, allows a coverage such as one representing a Digital Elevation Model (DEM), to be visualized in a three-dimensional AR view as shown in Figure 2. This facilitates 'tabletop' visualization so that a group of people could potentially stand around a table and see geographic representation superimposed onto that table, with the DEM viewed either through smart glasses or a smartphone. The AR application can ingest coverages encoded in GeoTIFF format, therefore the application could be served by an implementation of OGC API - Coverages.