OSGeo - User contributions [en]

MetaCRS

2016-08-08T11:58:06Z

Wiki-Hugueswski:

'''NOTE: This document has migrated to the MetaCRS Trac Wiki, and is now at: http://trac.osgeo.org/metacrs/wiki/WikiStart'''

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== Background ==

MetaCRS is a project encompassing several projections, and coordinate system related technologies. Our plan is to treat a variety of coordinate system activities as one Project from an OSGeo point of view. This helps provide enough "project mass" to justify the full OSGeo project treatment. But more importantly it would give us a forum to cooperate. Sharing things like coordinate system dictionaries, test suites and mathematical formulations.

== Project Steering Committee ==

The project steering committee consists of the following individuals and operates according to the [[MetaCRS PSC]] procedures.

* Frank Warmerdam (chair)
* Simon Liu
* Norm Olsen
* Mike Adair
* Howard Butler
* Martin Davis

== Sub-projects ==

The following are sub-projects of MetaCRS:

* [http://trac.osgeo.org/proj PROJ.4] - lead - Frank Warmerdam
* [http://trac.osgeo.org/proj4js Proj4js] - lead - Mike Adair
* [http://trac.osgeo.org/csmap CS-Map] - lead - Simon Liu
* [http://geotiff.osgeo.org/ GeoTIFF/libgeotiff] - lead - Frank Warmerdam
* [http://spatialreference.org/ SpatialReference.org] - lead - Howard? Chris?
* [http://trac.osgeo.org/proj4j/ Proj4J] - lead - Martin Davis

== Committers ==

Committers are technically able to commit on any part of MetaCRS but traditionally they have sub-projects on which they focus, and they will avoid commits on other sub-projects without discussion with the project lead. New committers may be [https://www.osgeo.org/cgi-bin/auth/ldap_group.py?group=metacrs added] after a vote of the PSC.

* Howard Butler (hobu): libgeotiff, spatialreference.org
* Mike Adair (madair): Proj4js
* Norm Olsen (normolsen): CS-Map
* Paul Ramsey (pramsey): libgeotiff
* Frank Warmerdam (warmerdam): PROJ.4, libgeotiff
* Chris Schmidt (crschmidt): spatialreference.org
* Richard Didier (drichard): PROJ.4
* Martin Davis (?): Proj4J
* Landon Blake (surveyor): Proj4J, testsuite
* Martin Desruisseaux (desruisseaux): testsuite

== Mailing list ==

In order to facilitate further discussion I have created a mailing list. Please join if you have an interest.

http://lists.osgeo.org/mailman/listinfo/MetaCRS

== Practical Questions ==

Answers are not authoritative - they are one opinion on possible answers.

=== Are we trying to merge the source into one super-library? ===

No, though there may be opportunities that arise for consolidation over time.

=== Is my library/component going to be subject to the whim of other contributors? ===

I imagine we will want to use the ''lieutenant model'' of development where particular components are essentially maintained by a chief maintainer. The project steering committee would establish broad policy (such as contributor rules) and facilitation for shared components (perhaps some dictionaries) while leaving technical direction of some components to their primary maintainer (ie. Norm for CS-Map).

=== So will all these packages live in a single subversion repository with a single Trac instance? ===

The current plan is to use a single SVN repository for MetaCRS projects (http://svn.osgeo.org/metacrs) with distinct subtrees for each project. But each project has the option of it's own distinct Trac instance - for example http://trac.osgeo.org/proj and http://trac.osgeo.org/proj4js.

=== What are Java developers doing on the mailing list? ===

The Java developers come from a range of projects; and are very interested in geeking out about correctness and accuracy issues. There are also a couple opportunities for collaboration (shared testing scripts and the like).

We will seek close cooperation with a variety individuals and organizations interested in interchange of spatial reference system descriptions, and related standards including other open source projects, organizations like OGC, national mapping agencies, and proprietary software developers.

== Non-Programming Collaboration ==
What opportunities are there for collaboration with projection libraries in languages that are not directly compatible with C programming language or C++ programming language libraries? (For example: GeoTools includes functional code for spatial reference systems in Java based on the ESPG database.)

Suggestions:
* Common Spatial Reference System or Coordinate Reference System Names and Descriptions
* Coordinate System (and CRS related object) dictionaries. Stuff like the EPSG dictionary.
* Datum shift lists (towgs84), and datum grid shift files (NTv1, etc).
* Transformations, calculations, and algorithms written in pseudocode that can be edited in different languages.
* Descriptions of spatial reference systems that can be used by developers in different programming languages.
* Notes on transformation from different representations of a CRS (WKT, PROJ.4, GCTP, GML,...).
* Test suites with test points in a variety of coordinate systems and their lat/long and WGS84 equivalents).
* Articles on spatial reference systems and translations useful for programmers interested in spatial reference system implementations. For example:
** Understanding The Difference Between National Vertical Datum of 1929 and the North American Datum of 1988

== Standard MetaCRS Test Data Files ==

Work has begun on a set of standard test data files that can be used to verify the coordinate transformations/conversions performed by
the various OSGeo projects that fall under the MetaCRS umbrella. You can learn more on the [[Standard MetaCRS Test Data Files]] wiki page.

MetaCRS PSC

2008-08-14T18:25:32Z

Wiki-Hugueswski: /* Summary */

= RFC#1: MetaCRS Project Steering Committee Guidelines =

Author: Frank Warmerdam

Contact: warmerdam@pobox.com

Status: Adopted

== Summary ==

This document describes governance and decision making for the [[MetaCRS]] Project.

The MetaCRS project is a effectively a confederation of projects related to coordinate reference system handling and transformations. As such, it's governance is somewhat decentralized with some component projects operating in a partially autonomous manner. On initiation the sub-projects are [http://trac.osgeo.org/csmap CS-MAP], PROJ.4 and PROJ4JS.

Each sub-project has a project lead who is considered primarily responsible for the sub-project. It is anticipated that most technical decisions will be made within the sub-projects on the basis of consensus, and be supervised by the sub-project lead.

However, the MetaCRS Project Steering Committee exists to make decisions on contentious sub-project decisions, matters that cross sub-project boundaries and official matters relating to OSGeo project governance such as committer approval.

== Detailed Process ==

# Proposals are written up and submitted on the metacrs@lists.osgeo.org mailing list for discussion and voting, by any interested party, not just committee members.
# Proposals need to be available for review and voting for at least two business days before a final decision can be made.
# Respondents may vote "+1" to indicate support for the proposal and a willingness to support implementation.
# Respondents may vote "-1" to veto a proposal, but must provide clear reasoning and alternate approaches to resolving the problem within the two days.
# A vote of -0 indicates mild disagreement, but has no effect. A 0 indicates no opinion. A +0 indicate mild support, but has no effect. Not voting is also an acceptable way of indicating no opinion.
# Anyone may comment on proposals on the list, but only members of the Project Steering Committee's votes will be counted.
# A proposal will be accepted if it receives +2 (including the proposer) and no vetos (-1).
# If a proposal is vetoed, and it cannot be revised to satisfy all parties, then it can be resubmitted for an override vote in which a majority of all eligible voters indicating +1 is sufficient to pass it. Note that this is a majority of all committee members, not just those who actively vote.
# Upon completion of discussion and voting the proposer should announce whether they are proceeding (proposal accepted) or are withdrawing their proposal (vetoed).
# The Chair gets a vote.
# The Chair is responsible for keeping track of who is a member of the Project Management Committee.
# Addition and removal of members from the committee, as well as selection of a Chair should be handled as a proposal to the committee. The selection of a new Chair also requires approval of the OSGeo board.
# The Chair adjudicates in cases of disputes about voting, or procedure, and can choose to extend the voting period if it is judged helpful to reaching consensus.

== When is Vote Required? ==

Generally speaking, technical decisions should be made by consensus within sub-projects. However, if a decision cannot be decided by consensus of the commiters involved in the sub-project, any commiter can request the decision be brought to a vote of the MetaCRS PSC. Technical decision that would be suitable for such a process include:

* Anything that could cause backward compatibility issues.
* Adding substantial amounts of new code.
* Changing inter-subsystem APIs, or objects.
* When releases should take place.
* Anything that might be controversial.

The MetaCRS PSC will also be directly responsible for some activities, particularly activities that cross sub-project boundaries such as interpreting coordinate system definitions, work on CRS dictionary tools, development of cross project test suites, and establishing best practices for coordinate system interchange and expression.

The MetaCRS PSC will always be responsible for:

* Approval of project commiters.
* Approval of sub-project leads.

== Observations ==

* The Chair is the ultimate adjudicator if things break down.
* The absolute majority rule can be used to override an obstructionist veto, but it is intended that in normal circumstances vetoers need to be convinced to withdraw their veto. We are trying to reach consensus.
* While it is generally intended that sub-projects operate fairly automously, the MetaCRS PSC always has the ultimate right to impose decisions on sub-projects.

== Bootstrapping ==

Frank Warmerdam is declared initial Chair of the MetaCRS Project Steering Committee.

Hugues Wisniewski, Norm Olson, Frank Warmerdam and Mike Adair are declared to be the
founding Project Steering Committee. The current list will be maintained by the MetaCRS
chair on the MetaCRS web pages.