OGC Requests

The Open Geospatial Consortium (OGC) seeks comments on the draft charter of a proposed Earth Observation Exploitation Platform Domain Working Group (DWG).

Earth Observation (EO) data captured by satellites has always been ‘big’ but an ever-increasing number of satellites capturing data at higher spatial and spectral resolutions has meant that client access to EO data has required larger and larger downloads, and even in-house IT infrastructure just to manage the volume of data. Thus, the incentive to create cloud-based, web-accessible platforms in which to access and analyse EO data on-the-fly has also grown in recent years.

This incentive has meant that cloud-based EO ‘Exploitation Platforms’ have been independently developed by many public organizations and commercial companies. However, their independent development has also hampered interoperability between these platforms. The next step in this data exploitation revolution, then, is to link the platforms together to create an ecosystem in which each platform can contribute its offered services to the implementation of more complex use cases.

For example, a scientist assessing climate changes may need data across several providers - from vegetation indexes, to predictive rainfall models and more - in order to answer a research question. Standardized elements of EO Exploitation Platforms could provide a single interface for this climate scientist where each ‘cloud’ talks to each other in the background, sharing the data, applications, tools and services between the platforms to generate a final ‘picture’ for the scientist.

Indeed, the ESA EO Exploitation Platforms built to date all share a common set of functionalities ripe for standardization:

• Data provisioning;
• Information visualization and analysis;
• Data processing; and
• User Authentication, Authorization, and Accounting.

This Domain Working Group will bring together service and technology providers of Earth Observation Data Exploitation Platforms in order to define a standards-based framework for the platforms’ interfaces that addresses and unifies the platforms through this common set of functionalities.

Third edition of this Abstract Specification describes the requirements for creating coordinate systems referencing locations in space and time.

The Open Geospatial Consortium (OGC) seeks public comment on the third edition of the Abstract Specification Topic 2: Referencing By Coordinates.

Aligned with the draft third edition (2018) of ISO 19111, Geographic Information - Referencing by coordinates, the Abstract Specification describes the data elements, relationships, and associated metadata required for spatial referencing by coordinates, expanded from a strictly spatial context to include time. The document was prepared by the OGC Coordinate Reference Systems Standards Working Group in close collaboration with ISO Technical Committee ISO/TC 211, Geographic information/Geomatics.

In addition to describing a coordinate reference system, the Abstract Specification provides for the description of a coordinate operation between two different coordinate reference systems, or a coordinate operation to account for crustal motion over time. With such information, spatial data referenced to different coordinate reference systems can be referenced to one specified coordinate reference system at one specified time. This facilitates spatial data integration. Alternatively, an audit trail of coordinate manipulations can be maintained.

This third edition cancels and replaces the second edition (OGC Topic 2 of 2008), which has been technically revised. This document also incorporates the provisions of OGC Topic 2.1 of 2010, which is to be cancelled.

The changes in this edition compared to the previous edition are:

• inclusion of applicable modern geodetic terminology;
• extension to describe dynamic geodetic reference frames;
• extension to describe geoid-based vertical coordinate reference systems;
• extension to allow triaxial ellipsoid for planetary applications;
• extension to describe three-dimensional projected coordinate reference systems;
• addition of 'datum ensembles' to allow grouping of related realizations of a reference frame where for lower accuracy applications the differences are insignificant;
• clarification in the modelling of derived coordinate reference systems;
• remodelling of the metadata elements scope and extent;
• addition of requirements to describe coordinate metadata and the relationship between spatial coordinates.
• additional modelling of temporal coordinate reference system components sufficient for spatio-temporal coordinate referencing;
• consolidation of the provisions of OGC Abstract Specification Topic 2.1 (Spatial referencing by coordinates - Extension for parametric values) into this document;
• change in name from 'Spatial referencing by coordinates' to 'Referencing by coordinates', due to the inclusion of the non-spatial coordinate reference system subtypes of parametric (from Abstract Specification topic 2.1) and temporal.
• the correction of minor errors.

The various OGC Abstract Specifications provide the conceptual foundation for most OGC standards development activities. Open interfaces and protocols are built and referenced against Abstract Specifications, thus enabling interoperability between different brands and different kinds of spatial processing systems. The Abstract Specification provides a reference model for the development of OGC Implementation Standards.

The Open Geospatial Consortium (OGC) seeks public comment on the OGC Web Services Security Candidate Standard.

For years various implementations of OGC Web Services have integrated some degree of security through Information Assurance (IA) controls . However, these implementations break interoperability, as they each extend the functionality of OGC Web Service (OWS) standards differently. As such, interoperability between secured OGC Web Services and clients is limited to systems custom-built to work with an IA implementation.

The objective of the OGC Web Services Security Standard is to allow the hosting of OWS on HTTPS, the implementation of IA controls and to advertise its existence in an interoperable way with no impact to existing implementations using a backwards-compatible approach. No changes to existing OGC Web Services standards are required. The approach used in this candidate standard is based on existing functionality in the OGC Web Services Capabilities document in a consistent manner.

Uptake of the standardized approach as a build-in to new OGC Web Services standards will ensure security interoperability.

This standard has come as a result of research undertaken during OGC Testbeds 11, 12, and 13, part of OGC’s Innovation Program.

The Open Geospatial Consortium (OGC) seeks public comment on the OGC SensorThings API, Part 2 - Tasking Core Candidate Standard. The OGC SensorThings API is a free and non-proprietary lightweight interface specification that simplifies and accelerates the development of Web-based Internet of Things (IoT) applications.

The OGC SensorThings API provides an open, geospatial-enabled, and unified way to interconnect the IoT devices, data, and applications over the Web. Part 1 was released in 2016 and allowed management and reception of observations or measurements made by IoT sensors. Part 2 provides a mechanism to tell the sensor/actuator what to do

Application developers can use this open standard to connect to various IoT devices and create innovative applications without needing to individually integrate the heterogeneous protocols of the different IoT devices, gateways, and services. System manufacturers can embed the OGC SensorThings API in their IoT hardware and software platforms so that the different platforms’ IoT devices can effortlessly connect with other servers that implement the standard. Because device location communication is useful in almost every IoT application, an open, lightweight, widely used standards-based location encoding is part of the SensorThings API.

This new standard is designed specifically for resource-constrained IoT devices and the Web developer community. The candidate standard follows REST principles and uses an efficient MQTT transport and the flexible OASIS OData URL conventions.

The candidate OGC SensorThings API Standard was designed to be compatible with a rich set of proven and widely-adopted open standards, such as the Web protocols and the OGC Sensor Web Enablement (SWE) standards, including the ISO/OGC Observation and Measurement Encoding Standard. Thus, the OGC SensorThings API is extensible and can be applied in both simple and complex use cases.

At a high level, the OGC SensorThings API provides two main functionalities: Sensing, and Tasking. Each function is handled by a part. The Sensing part, an official OGC standard since 2016, provides a standard way to manage and retrieve observations and metadata from heterogeneous IoT sensor systems.

This, the Tasking part, provides a standard way for parameterizing - also called tasking of - task-able IoT devices, such as sensors, actuators, drones, or even satellites.