Publication Date: 2019-01-20
Approval Date: 2018-11-12
Submission Date: 2018-09-21
Reference number of this document: OGC 18-084
Reference URL for this document: http://docs.opengeospatial.org/per/18-084
Category: Public Engineering Report
Editor: Luis Bermudez
Title: OGC Geospatial to the Edge Plugfest Engineering Report
COPYRIGHT
Copyright © 2019 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 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. Summary
- 2. References and abbreviated terms
- 3. Overview
- 4. Plugfest description
- 5. Results and recommendations
- 6. Test suites issues and releases
- 7. Applications and strategies from implementers
- 8. Initiative Feedback
- Appendix A: Revision history
1. Summary
The Geospatial to the Edge Interoperability Plugfest, co-sponsored by the Army Geospatial Center and the National Geospatial-Intelligence Agency (NGA/CIO&T), brought together technology implementers and data providers to advance the interoperability of geospatial products and services based on profiles of OGC standards. Specifically, servers and data available via GeoPackage, Web Feature Service (WFS), Web Map Service (WMS), and Web Map Tile Service (WMTS), all following National System for Geospatial Intelligence (NSG) profiles, were exercised and improved in various clients. Compliance Tests were executed and advanced based on feedback from the participants.
1.1. Motivation
The geospatial communities supporting defense, emergency response, and intelligence rely on geospatial data and open standards to accomplish their missions. Profiles of standards and data models were used to ensure sharing of data meet their specific needs. Profiles provide strict implementation guidance to ensure interoperability of geospatial systems and data in these highly specialized and demanding environments. Implementations following profiles compliant with open standards support mission critical operations for enhancing effective and efficient execution.
A Plugfest is an initiative of the OGC Innovation Program. Plugfests provides the right venue for sponsors and technology implementers to come together in a collaborative agile process to solve geospatial challenges. The Plugfest assisted tool enhancement and provided guidance to improve the delivery of enterprise geospatial data to end users. In this initiative, a Plugfest was used to bring more than thirteen data/service producers and clients of data following NSG profiles. The plugfest help discover implementation issues and advance executable test suites.
1.2. Prior-after comparison
Before the Plugfest, very few implementations were able to interact with NSG profiles of OGC standards. This is commonly the case when communities want to restrict a rule from the base standard or want to extend what the base standard offers. Support for NSG profiles is not commonly a feature that comes packaged in software products. After the Plugfest more implementations became available that implement the NSG profiles for GeoPackage, WMS, WFS, and WMTS.
The profiles implemented in the Plugfest had corresponding executable test suites. These profiles test suites were in beta by the end of the initiative, ready to be move forward for public release by the OGC Technical Committee. Feedback related to the executable test suites was provided by the participants. In particular, the GeoPackage test was improved during the Plugfest.
1.3. Recommendations for future work
Plugfests should be performed for any new profile of an existing OGC standard or any new candidate OGC standard including revisions. Allowing participants to come together to solve interoperability issues has high value in maturing and stress testing implementations of profiles or candidate standards. The result, of high value to the geospatial community, is improvement of the standards and advancement of test suites.
Recommendations for implementing the profiles in regards to the specific profiles are detailed in the Results and Recommendations Section.
1.4. Document contributor contact points
All questions regarding this document should be directed to the editor or the contributors:
Contacts
Name | Organization |
---|---|
Luis Bermudez |
OGC |
1.5. 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.
2. References and abbreviated terms
2.1. References
The following normative documents are referenced in this document.
-
NSG GeoPackage 2.1 (raster and vector data), based on the OGC GeoPackage 1.1 standard: https://nsgreg.nga.mil/doc/view?i=4379
-
NSG WMS 1.0 (raster data), based on the OGC WMS 1.3 standard: https://nsgreg.nga.mil/doc/view?i=4209&month=11&day=13&year=2017
-
NSG WMTS 1.1 (raster data), based on the OGC WMS 1.0 standard: https://nsgreg.nga.mil/doc/view?i=4448
-
NSG WFS 1.0 (vector data), based on the OGC WFS 2.0 standard: https://nsgreg.nga.mil/doc/view?i=4388&month=11&day=17&year=2017
2.2. Abbreviated terms
-
CSV Comma-separated values
-
DoD United States Department of Defense
-
ESA European Space Agency
-
GEOINT Geospatial Intelligence
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GGDM Ground-Warfighter Geospatial Data Model
-
GMES Global Monitoring for Environment and Security
-
GML Geography Markup Language
-
IC Intelligence Community
-
JSON JavaScript Object Notation
-
NAS NSG Application Schema
-
NSG National System for Geospatial Intelligence
-
NSGM National System for Geospatial-Intelligence Manual
-
OGC Open Geospatial Consortium
-
WFS Web Feature Service
-
WMS Web Map Service
-
WMTS Web Map Tile Service
3. Overview
This OGC Plugfest, co-sponsored by Army Geospatial Center and the National Geospatial-Intelligence Agency (NGA/CIO&T), brought together technology implementers and data providers to advance the interoperability of geospatial products and services based on community profiles of existing OGC standards . The Plugfest assisted in tool enhancement and provided guidance to improve the delivery of enterprise geospatial data to end users.
Examples of how end user communities will benefit from this work are:
-
First responders, relief workers and fire fighters preparing for and operating in austere network environments;
-
Emergency planners and managers supporting hurricane, wildfire, and earthquake preparedness, relief/response activities and damage assessment; and
-
Soldiers/warfighters during planning and executing operations specifically in disconnected, intermittent, and limited network environments.
The geospatial communities supporting defense, emergency response, and intelligence rely on geospatial data and open standards to accomplish their mission. To make sharing of data meet their specific needs, they require the definition, testing, and community approval of profiles of existing OGC standards. Profiles provide strict implementation guidance to ensure interoperability of geospatial systems in these highly specialized and demanding environments. Non-compliance to open standards profiles prohibits mission critical operations from executing effectively and efficiently.
Note
|
The OGC membership recently approved an official definition of the concept ”profile” that includes the case in which a profile extends the base standard. NSG Profiles are of the latter type of profile and in the future these types of profiles should be referred as Profiles with Extension. Profiles restrict (remove) options (e.g., file formats or coordinate reference systems) that may be specified in the base standard. GML Simple Features is an example of a profile that restricts the number of requirements to be implemented. Extensions add options and/or capabilities that are not included in the base standard. |
Additionally, members of the Intelligence Community (IC), United States Department of Defense (DoD), non-DoD/IC Federal agency members of the NSG, international partners, state/local municipalities, and Native American tribal organizations that are responsible for the operation, acquisition and/or development of systems and applications which collect, procure, produce, serve, exchange, or use Geospatial Intelligence (GEOINT) data are mandated to comply with NSG implementation standards (NSGM 3202). Support of these standards, which may be profiles of OGC standards, affect government acquisition decisions to ensure that all systems within the government can communicate appropriately. [From GEOINT Functional Manager Standards Assessment (GFMSA) Program Manual, NSGM 3202, June 2016]
A Plugfest, an initiative of the OGC Innovation Program, provides a collaborative venue for sponsors and technology implementers to come together in a agile process to solve geospatial challenges. A plugfest provides the scenario and testing environment to advance implementation of profiles in commercial and open source software products. A Plugfest allows organizations to test and validate that their software products can interoperate with other products implementing the same standard or profiles of a standard.
4. Plugfest description
4.1. Goal
The goal of this OGC Plugfest was to increase interoperability of information systems using community defined profiles. The Plugfest assisted in tool enhancement and provided guidance to improve the delivery of enterprise geospatial data to end users.
4.2. Profiles
The profiles used in the initiative were:
-
NSG GeoPackage 2.1 (raster and vector data) profile, based on the OGC GeoPackage 1.1 standard: https://nsgreg.nga.mil/doc/view?i=4379
-
NSG WMS 1.0 (raster data) profile, based on the OGC WMS 1.3 standard: https://nsgreg.nga.mil/doc/view?i=4209&month=11&day=13&year=2017
-
NSG WMTS 1.1 (raster data) profile, based on the OGC WMS 1.0 standard: https://nsgreg.nga.mil/doc/view?i=4448
-
NSG WFS 1.0 (vector data) profile, based on the OGC WFS 2.0 standard: https://nsgreg.nga.mil/doc/view?i=4388&month=11&day=17&year=2017
4.3. Plugfest participation roles
The participants in the Plugfest took the following roles:
-
Data Providers were organizations providing data sources either serving it via OGC services or providing file.
-
Service Providers were organizations that produced services for clients to access.
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Client Providers were organizations that provided clients that consumed GeoPackage data and services to be used for a specific purpose.
4.4. Sprints
Sprints happened virtually allowing participants around the world to participate and to minimize costs related to travel. Each sprint lasted for 1 week. During the sprint week participants were available to respond to inquiries posted by other participants. In the sprint time clients performed a set of operations following a scenario and documented their success and failures.
Two sprints were executed in this Plugfest.
Sprint 1 tested existing commercial and/or open source products against the scenarios. A limited (not for public dissemination) report on Sprint 1 findings, not revealing vendor information, was shared with the Sponsors and relevant OGC Standards Working Groups. The findings that include the need for improvement in data structure, servers and clients were documented.
Sprint 2 Occurred 3 months after Sprint 1 was completed and documented. Sprint 2 repeated the tests performed in Sprint 1. Participants had three months to improve their software to better create the GeoPackage files and improve their services and clients based on the feedback from Sprint 1.
4.5. Schedule
-
March 6 - Participants kickoff (Pre-sprint clarification open to registered participants)
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March 30 - Update scenarios
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April 16 - Information about sources (data and servers) was provided to the OGC
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April 20 - Data and Servers ready for Sprint 1
-
April 23-27 - Sprint 1 clients testing
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April 30-May 11 - Compilation of results by OGC staff
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April 30-July 16 - Discussions in GitHub issue tracker
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July 16 - Information about data and servers was provided to the OGC
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July 20 - Data and Servers ready for Sprint 2 (Improved services based on feedback from Sprint 1)
-
July 23-Aug 2 - Sprint 2 clients testing
-
September 9 - Draft engineering report
-
September 28 - Report submission to the OGC TC for public release approval
4.6. Data
Two types of geospatial data, based on NSG Profiles, were used in the plugfest:
-
Vector data used to create, publish and ingest GeoPackage files as well as to publish to and ingest data from WFS servers.
-
Raster data used to exercise WMS and WMTS servers.
4.6.1. Vector data
Vector data used in the Plugfest was based on the Ground-Warfighter Geospatial Data Model (GGDM 3.0), which is based on the NSG Application Schema (NAS) version 7. Various files were created using the GGDM 3.0 schema, which were used by participants to create GeoPackages or vector files that were served via Web Feature Service (WFS) service instances.
The NAS Model Entity Catalog provides a set of features, attributes and enumeration values to be used when encoding vector information. The catalog was provided as an Excel File. It was used by participants to better understand the semantics of the feature types (semantics) of the data.
The was area if interest for the data was based on Puerto Rico. The datasets contained the following layers.
-
USGS Puerto Rico data for roads and trails, airports, rivers, selected buildings, built-up areas, and some surface areas including runways, counties, a forest, cemeteries and conservation areas.
-
US Transportation Data from which Heliport and Water Aerodrome points extracted from airport data and ports and anchorages extracted from existing port data.
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US Maritime data for maritime limits restricted to the Puerto Rico area.
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US Census Bureau coastlines restricted to land/water boundaries for the Puerto Rico area.
The Data was available for download in the following formats:
-
Composite ArcGIS (10.1+) File Geodatabase in flattened mode with feature datasets and with no subtypes
The list of features types contained in the source files was as follows:
-
ADMINISTRATIVE_SUBDIVISION_S
-
BUILDING_P
-
BUILT_UP_AREA_P
-
CEMETERY_S
-
CONSERVATION_AREA_S
-
DAM_C
-
DAM_S
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DATASET_S
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DOLPHIN_P
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ENTITY_COLLECTION_METADATA_S
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FORESHORE_S
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FOREST_S
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GAUGING_STATION_P
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HELIPORT_P
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INLAND_WATERBODY_S
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LAND_AERODROME_P
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LAND_WATER_BOUNDARY_C
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MARITIME_LIMIT_C
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MILITARY_INSTALLATION_S
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NAVIGABLE_CANAL_S
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PARK_S
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PIPELINE_C
-
PORT_P
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REEF_C
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RIVER_C
-
RIVER_S
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ROAD_C
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ROCK_FORMATION_P
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RUNWAY_S
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SOIL_SURFACE_REGION_S
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TRAIL_C
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TUNNEL_C
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WATER_AERODROME_P
-
WATER_WELL_P
4.6.2. Raster data
The raster data for the plugfest was based on the Sentinel 2A Multispectral Instrument (MSI), which was made available by the European Space Agency (ESA) within the Global Monitoring for Environment and Security (GMES) programme. The true color composites (red, green, blue) from the orthorectified Level-lC products were used to generate map data for WMS, WMTS, and GeoPackage files.
The Sentinel data are freely available through the Copernicus Open Access Hub. The data used in the Plugfest corresponded to the region of Puerto Rico and the True Color Image (TCI).
The Table below lists the subset Product ID’s from the Sentinal 2A mission that were used by the data providers. From each image set, the *TCI.jp2
image was used to create the output products. Participants used the Copernicus Hub recommend API script to download each dataset.
Product ID | Unique ID (API access) |
---|---|
S2B_MSIL1C_20171209T150709_N0206_R082_T19QFA_20171209T195400 |
a6a9d67d-fbd5-47be-b5c7-92d680b5028b |
S2B_MSIL1C_20171209T150709_N0206_R082_T19QGA_20171209T195400 |
2c6a75a4-7327-45b0-b493-ea9a40982b13 |
S2B_MSIL1C_20171209T150709_N0206_R082_T19QGV_20171209T195400 |
2590351c-a1ae-4592-9b3d-83358d8b13f1 |
S2B_MSIL1C_20171209T150709_N0206_R082_T19QHA_20171209T195400 |
87f334c4-1993-409a-bd46-79a58a8ba243 |
S2B_MSIL1C_20171209T150709_N0206_R082_T19QHV_20171209T195400 |
96c5aee0-68d9-4c11-8182-e78b8adca7c1 |
S2A_MSIL1C_20161219T150712_N0204_R082_T19QFV_20161219T150714 |
31d6900f-3164-4243-84f8-84d39982a4fe |
After setting up an account, the unique id can be plugged in the URL string to form the link for download. For example:
https://scihub.copernicus.eu/dhus/odata/v1/Products('a6a9d67d-fbd5-47be-b5c7-92d680b5028b')/$value
After downloading the data the participants were responsible for the merge and tiling of this imagery data as per the NSG specifications for raster data.
4.7. Data consumer testing reports during sprints
4.7.1. Organizations acting as clients/users
The following organizations acted as clients/users of the Plugfest.
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AGC-Nett Warrior
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AGC-Sitaware
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Distributed Common Ground System–Army (DCGSA)
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Compusult
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Envitia
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Esri
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Image Matters
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U.S. Naval Research Laboratory (NRL)
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Visual Awareness Technology and Consulting (VATC)
4.7.2. Data, services and templates
The Data and Services were provided by:
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AGC-ENFIRE
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Aviation and Missile Research Development and Engineering Center (AMRDEC)
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Compusult
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Distributed Common Ground System–Army (DCGSA)
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Esri
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GeoSolutions
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U.S. Naval Research Laboratory (NRL)
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Visual Awareness Technology and Consulting (VATC)
The name of the sources were anonymized. The links and templates used in Sprint 1 are detailed in the table below.
Source type | Source short name (with link) | Template used to report |
---|---|---|
GeoPackage_Vector |
||
GeoPackage_Raster |
||
WMS |
||
WMS |
||
WMTS |
||
WMTS |
The links and templates used in Sprint 2 are detailed in the table below.
Source type & Source short name | Template to provide feedback |
---|---|
[GeoPackage_Vector_Rigel] |
|
[WMTS_Calypso] |
|
4.7.3. Communications
If there were any issues with a test, the questions were logged to the issue tracker. Participants were encouraged to watch the repository during the sprint so they would be notified and be able to provide comments if a question from another participant came up.
4.8. Templates
Each user (client) had to test a data or server and then answer a set of questions. The questions for the vector and raster sources are summarized in this section.
4.8.1. Vector questions
Inland water body query
Find all inland water bodies where the full name starts with 'Lago’ and the highest elevation is greater than 70.
Reservoir query
Find all inland water bodies where the inland water type is reservoir and the area is greater than 0.046.
Trail Number query
Provide the full names of all trails that have specified domain value attribute containing the string subset: TraillNumber:T300.
Guaynabo query
Find all built up areas where the height is less than 35, the memorandum is ‘San Juan’, and the World Port Index Identifier is 'Guaynabo'.
Firefighting Carretera query
Find all buildings where the address does not contain Carretera, the feature function is firefighting, and the specified domain value starts with '(Zipcode:006'.
S1200 query
Find all roads where the geography name is 'Pr- 20', and where the feature unique identifier is S1200.
Conservation area query
Find the largest conservation area based on area and report the full name of that conservation area. What is the full name? What is the Area? Provide a screenshot.
4.8.2. Raster questions
Provide screenshot for the zooms (and scales) specified.
Note: In the below requests, the center point of a designated area is identified. The participant should go to the center point and then zoom to the designated scale and take a screen capture of the resulting image. The screen capture should be bigger (contain) than the image returned to ensure that we will be able to compare images returned by different clients.
Scale: 1:500,000
The extent of the image returned should be centered on the centroid of Puerto Rico, which is approximately this location: EPSG 4326: - 66.66, 18.20 and then zoom to the 1:500,000 scale. If the designated scale is not available, zoom to the closest scale that is available and include that information along with the image.
Scale: 1:20,000
The extent of the image returned should be centered on the centroid of Puerto Rico, which is approximately this location: EPSG 4326: - 66.66, 18.20 and then zoom to the 1:20,000 scale. If the designated scale is not available, zoom to the closest scale that is available and include that information along with the image.
5. Results and recommendations
5.1. Summary of experiments
The results of Sprint 1 were summarized in the following table.
The first row provides the label used to identify each client in an anonymized way. For example: Client E, Client L, etc. In total, ten clients were used in the Plugfest.
The first column identifies the sources of data and servers. The contributions were also anonymized. They were sorted in the table by the type of contribution. For example, the Plugfest had 3 WMTS servers: Pluto, Calypso, and Oberon.
The red marks indicate that the client was not able to interact with the server provider. Overall most servers were able to communicate with the clients.
The results for Sprint 2 are shown in the Sprint 2 Results table. Similar to the previous table, it shows if a client was able to interact with the server provider. In addition, it was also captured by shading the cells green if the client was able to successfully perform all the tests with a particular source.
5.2. Selected screenshots
In the following figures are some examples provided by the participants.
5.3. WMS
5.3.1. Use both name and title for naming layers
A server didn’t use the <Name> element to name the layer. Clients were not able to do GetMap request. The WMS 1.3 Specification states the role of <Title> and <Name>:
7.2.4.2 Names and titles
A number of elements have both a <Name> and a <Title>. The Name is a text string used for machine-to-machine communication while the Title is for the benefit of humans. For example, a dataset might have the descriptive Title “Maximum Atmospheric Temperature” and be requested using the abbreviated Name “ATMAX”.
Related issues:
5.4. WFS
5.4.1. Axis order
Data providers should treat properly urn:ogc:def:crs:epsg::4326. The axis order is Latitude Longitude. This can happen in the following situations:
-
When performing an HTTP request
-
When returning data about a feature
The snippet code bellow shows an incorrect axis order for Puerto Rico.
<gml:MultiSurface gml:id="INLAND_WATERBODY_S.5.pl" srsName="urn:ogc:def:crs:EPSG::4326" srsDimension="3"> <gml:surfaceMember> <gml:Polygon gml:id="INLAND_WATERBODY_S.5.pl.0" srsName="urn:ogc:def:crs:EPSG::4326" srsDimension="3"> <gml:exterior> <gml:LinearRing> <gml:posList>
-66.57471640699998 18.36690177100007 0
-66.57475487399995 18.36692017100006 0
-66.57479807399994 18.36692930400005 0
-66.57483167399994 18.36693850400007 0
-66.57488447399999 18.36694770400004 0
-66.57494700699993 18.36696597100007 0
5.4.2. Query issues
Some queries seem difficult to execute. Several clients reported that Query 10 can’t be executed:
Query 10: Find the administrative subdivision that contains the building “Cuerpo de Bomberos de Orocovis”
The process might involve a 2 step process:
-
Select the layer
-
Run a query inside that layer: select * from BUILDING_P WHERE ZI005_FNA="Cuerpo de Bomberos de Orocovis";
Similarly it was reported that it was only possible to query one layer per request (Issue 52).
A thin client didn’t support attribute querying (Issue 85).
Related issues:
5.5. WMTS recommendations
5.6. GeoPackage results
5.6.1. Raster and vector data in one file
The GeoPackage standard and NSG profile permit a user to include both raster and vector data in the same file. One provider combined the GGDM vector data with a patch of imagery at a higher resolution than the supplied Sentinel 2A data and also added an elevation raster dataset. Although their demo exceeded the scope of the prescribed tests, it highlighted the potential for doing useful raster/vector mashups within NSG profile guidelines. This screenshot shows the edge of the imagery patch overlaid on a public basemap.
5.6.2. Sort attributes in the SQLite schema
When users are interacting with clients and users are not experts in the data, it might be useful that the schema is presented in a more useful way. Sorting attributes alphabetically in the SQLite schema will allow to easier find attributes in user interfaces when selecting features to filter.
Related issues:
5.6.3. Remove local links
If GeoPackage files contain links to data producer local file system, some data (e.g styles) might not be accessible. In the testing, at least one client saw significant slowing in the opening and displaying of the data because of these links.
A client reported:
Selecting all layers caused QGIS 2.18 to show pinwheel of death for 15 minutes. Data loaded when selected only the 9 feature tables included in the test, excluding other feature tables and all style and attribute tables.
Since test does not require styled features it might be useful to omit style tables from schema, as they account for most of its size and complexity.
Related issues:
5.6.4. Investigate further GDAL validation issues
Several GDAL validation issues were reported that require further investigation with GDAL developers:
Related issues:
5.6.5. Investigate further GeoPackage performance
Some files >600 MB were slower to load. Need to investigate further the raw causes of such behavior.
Two files in Sprint 1 with raster data were 1 GB and 5 GB. Raster queries were easy to perform.
Related issue: #22 - Bigger files load slower
5.6.6. Investigate further transparency
Some clients reported apparent transparency in raster layers.
5.6.7. Mashups containing raster elevation data
All the clients were able to open the file containing both raster and vector data. The GeoPackage contained high resolution images and elevation data in the 2D gridded coverage extension schema. Tile-based, pyramidal, floating-point raster data is a distinguishing feature of GeoPackage.