Achieving OGC Compliance: GeoPackage 1.2, GeoTIFF 1.1, GML 3.2.1, KML 2.2.0

Introduction

FME 2021 currently implements 30+ OGC standards and has certified compliance to write GeoPackage 1.2, GeoTIFF 1.1, GML 3.2.1, and KML 2.2.0. This article will discuss the lessons learned through participating in the OGC’s certification process and suggest best practices for achieving compliance for some of the trickier standards (GML 3.2.1 and KML 2.2.0). The full certification specifications can be found here.  
 

OGC and Open Standards

users to build applications based on community-based standards to reduce dependency on specific vendors for support of proprietary formats. The OGC is the leading international organization creating standards to make geospatial information and services FAIR - Findable, Accessible, Interoperable, and Reusable. Getting OGC certified through The OGC Compliance Program helps organizations distinguish their products with a competitive edge in the marketplace. It serves as a universal credential that enables various industries to better integrate their solutions. Click here to read more about the importance of OGC & Open Standards. 
 

Testing for OGC Compliance

Validation of FME outputs were carried out on the TEAM Engine. The OGC’s TEAM Engine executes test suites developed using the TestNG framework or the OGC Compliance Test Language (CTL) to verify compliance. The installation maintained and hosted by the OGC can be accessed here. After creating an account, running a test is as simple as selecting the standards to test and uploading an output to test against. 



The OGC defines containers of coherent sets of requirements, referred to as conformance classes, that address the functionality of each standard. Each standard is accompanied by a list of conformance classes described in the appropriate encoding document. Depending on the standard, the encoding document will usually describe a Core conformance class that sets the minimum conformance requirements for certification followed by higher levels of conformance requirements with constraints that could hinder the utility, portability, or interoperability of the file if not conformed to. 



This diagram illustrates the general workflow that was required to validate and certify FME using the TEAM Engine. The yellow and blue boxes represent tasks carried out in FME and the TEAM Engine respectively. This workflow was efficient in diagnosing problems and discovering ways to achieve compliance by reconfiguring various features within FME.

OGC Compliant Standards in FME

OGC GeoPackage 1.2

Learn more about FME’s OGC GeoPackage Reader/Writer

GeoPackage is a platform-independent SQLite database file that contains the GeoPackage data and metadata tables. It supports direct use and can be accessed and updated without format translations. A GeoPackage that complies with OGC's standard does not implement vendor-specific extensions and are interoperable for enterprise or personal needs. GeoPackages are particularly compatible with mobile devices or in environments where there is limited connectivity and bandwidth. FME treats the tables in GeoPackages as features and provides read/write access to GeoPackage files. 

OGC GeoTIFF 1.1

Learn more about FME’s GeoTIFF Reader/Writer

GeoTIFF was developed in the early 1990’s with the goal of leveraging a mature platform independent file format (TIFF) by adding metadata that describes the geographic image data. GeoTIFF is used throughout geospatially involved communities to share geographic image data. The OGC provides an inclusive standardization process for the GeoTIFF user community by keeping up-to date with new requirements and needs for profiles, extensions, and improvements to the specification.

OGC GML 3.2.1 

Learn more about FME’s OGC GML Reader/Writer

GML is an XML language defined by the OGC to describe geographic features. There are 2 parts to understanding GML grammar - the schema that describes the document and the instance document that contains the actual data. In essence, a GML document is described using a GML Schema. The key capability of GML is its ability to integrate all forms of geographic information in a way that mainly concerns the representation of the geographic data content. This allows GML to serve as a modeling language for geographic systems as an open interchangeable format online. 

OGC KML 2.2.0 

Learn more about FME’s OGC/Google KML Reader/Writer

KML is an XML language that focuses on geographic visualization including annotations of maps and images. Geographic visualization not only presents graphical data on the globe, but also allows the user to control where they want to look. This functionality makes KML complementary to most key OGC standards.  KML was submitted by Google to the OGC for it to evolve within the OGC to be adopted as an implementation standard. The OGC has set objectives for KML as it continues to evolve that ensure that KML is managed properly in parallel with Google. 

Tutorials

Achieving Compliance: OGC GML 3.2.1
Achieving Compliance: OGC KML 2.2.0