Subject: SAIF, OGIS, SQL\MM: Just the FAQ's

From: [email-masked]
Date: Mon, 09 May 1994 11:59:36 -0700 (PDT)

To the Temporal GIS community

For those of you who don't know: OGIS is the Open Geodata Interoperability 
Specification, SQL\MM is the multi-media extension to SQL3 and SAIF is the 
Spatial ARchive and Interchange Format recently approved a Canadian Standard.
At this time OGIS and SQL\MM are based on SAIF 3.1.

As the SQL\MM and OGIS initiatives are gaining momentum I thought it might be 
useful to distribute some information about the cooperative (and not so 
cooperative) efforts that are ongoing.  As standards begin to emerge in the 
maturing GIS industry it is essential that the research and user communities 
have critical input into the process. Feel free to contact people listed in the 
atached document for more info.

Henry Kucera, P.Geo
Strategic Applications Team
Ministry of Environment
Province of British Columbia
Canada

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                    SAIF Frequently Asked Questions List 
                                 Version 1.00
                                April 27, 1994
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This is the first release of the FAQ (Frequently Asked Questions) for
the Spatial Archive and Interchange Format (SAIF).

This FAQ will be crossposted periodically to the following newsgroups: 

        comp.infosystems.gis
        sci.data.formats
        news.answers
        comp.answers

If you have any suggestions for corrections, changes, expansion or
further clarification of this FAQ, please send them to the SAIF FAQ
author and maintainer, Dale Lutz, care of "[email-masked]".

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The following topics are covered in this FAQ:
                                        
Q1: What is SAIF?
Q2: Where is SAIF being used?
Q3: Who created and maintains SAIF?
Q4: What is the SAIF toolkit?
Q5: Where can I get more information on SAIF?
Q6: Is the SAIF Specification on the Web?
Q7: What FTP sites carry the SAIF Specification document?
Q8: What's the easiest way to get familar with SAIF?

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Q1: What is SAIF?
-----------------
Spatial Archive and Interchange Format (SAIF, pronounced safe) is a
Canadian geomatics standard for the exchange of geographic data. The
underlying model itself is devoid of geographic meaning; rather it deals
with fundamental concepts from mathematics and computer science.  SAIF
uses an object oriented data model,  and consists of definitions of the
underlying building blocks, including tuples, sets, lists, enumerations,
and primitives.  It also includes the rules for defining higher level
constructs, and the SAIF standard defines a base set of approximately
300 classes.  These include such things as Points, Spatial Reference
Systems, Map Projections, Arcs, and Polygons.

By design, SAIF is intended to be extended by users through the
development of their own schemas.  SAIF has an object oriented data
definition language, Class Syntax Notation (CSN), which is used to
define new types.  In addition to being useful as the means of extending
SAIF, CSN is also the language employed to describe all of the types
included in the SAIF base schema.

Instances of objects in SAIF are expressed using Object Syntax Notation
(OSN), a simple character based notation.

There is also a binary exchange file format defined for SAIF data based
on the 'zip' compression format called SAIF/ZIP.  A toolkit is being
produced which will make it easy to read and write SAIF data in this
format (see Q4).

A company has formed to provide tools and training for the SAIF data
standard.  Safe Software may be contacted by email at [email-masked]
or by phone at either (604) 241-4424 or (604) 583-2016.

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Q2: Where is SAIF being used?
-----------------------------
In 1991 SAIF was accepted as a draft standard for the exchange of
geographic data by the Canadian General Standards Board, Committee on
Geomatics.  Since that time several upgrades have been made, culminating
in the current specification. SAIF has been approved (1993) through the
CGSB process as a national standard in Canada.  The province of
British Columbia has been using SAIF for more than two years.

The present document, Release 3.1, contains a number of significant
changes made in response to two related efforts.  The first involves the
development of the ISO SQL Multimedia Spatial standard. A new release of
SQL,  SQL3, is being developed. SQL/MM will be a companion standard. The
SQL/MM Spatial is a component of SQL/MM intended to address the
management of spatial and spatiotemporal data in the context of database
management systems.

The second effort concerns the development of the Open Geodata
Interoperability Specification (OGIS) under the auspices of the Open GIS
Foundation (OGF). The OGF has been designated (1994) by the U.S. Federal
Geographic Data Committee as the lead organization responsible for
defining an interoperability specification suitable for geoprocessing
activities.

Harmonization of SAIF, SQL/MM Spatial and OGIS is leading to a
common understanding of geomatics data. Integration with DIGEST
and SDTS is also being addressed.

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Q3: Who created and maintains SAIF?
-----------------------------------

SAIF is a product of the Geomatics Unit, Surveys and Resource Mapping
Branch (SRMB) of the British Columbia Ministry of Environment, Lands and
Parks. SRMB is involved in geographic data management, geographic
analysis, and image applications. The following individuals have been
involved with the SAIF initiative:

Joe Carr ------ SAIF Toolkit
   Internet: [email-masked]                Tel: (604) 387-1353
Peter Friesen - modelling and applications
   Internet: [email-masked]    Tel: (604) 387-9347
Henry Kucera -- databases and Canadian ISO SQL/MM Spatial contributions
   Internet: [email-masked]              Tel: (604) 356-2388
Mark Sondheim - SAIF formal definition; director of the SAIF initiative
   Internet: [email-masked]           Tel: (604) 387-9352

SRMB's fax number is (604) 356-7831. 

SRMB would like to extend special thanks to those in the ISO SQL, OGIS,
and Sequoia communities who have contributed both directly and
indirectly to SAIF.

SRMB staff have also provided material for this FAQ.

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Q4: What is the SAIF toolkit?
-----------------------------
At the moment, there are no tools available to manipulate SAIF data.
However, by the fourth quarter of '94, the SAIF Toolkit will be
available.  This toolkit is being developed for the Surveys and Resource
Mapping Branch of the BC Ministry of Environment, Lands and Parks by
Safe Software Inc. of Richmond, BC.  The toolkit will contain a C
library for reading and writing data in SAIF format, which will simplify
the creation of SAIF translators.  As well, the toolkit will contain
tools to allow inspection and testing of SAIF Schemas.

The Toolkit is designed to work with SAIF datasets. Four points are
noteworthy:

1   Each SAIF dataset may contain a mix of data in SAIF format and other
    formats. (This capability may be of interest for example in
    multimedia applications.)
2   The Toolkit is being designed to accommodate datasets which may
    range in size from very large to very small.
3   Objects in a SAIF dataset may reference other objects in the dataset
    through object identifiers; they may also reference objects outside
    the dataset.
4   Geographic data in SAIF format, resident in a SAIF dataset, occupies
    significantly less space than typical proprietary formats associated
    with commercial GIS systems.

Although portability is the goal, the toolkit will initially target the
Windows 3.1 and Solaris platforms.  It is being written in C++ and will
be useable by both C and C++ developers in both Unix and Microsoft
Windows environments.

Safe Software will also be producing a suite of SAIFTools which will
supplement those provided by the toolkit.

If you are interested in more information about the SAIF Toolkit or
would like to participate in its testing or design reviews, please
contact Joe Carr.

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Q5: Where can I get more information on SAIF?
---------------------------------------------
1)  Safe Software maintains a home page for SAIF at this URL:  

        http://www.wimsey.com/~infosafe/saif/saifHome.html

    This home page will be continually updated to point to all known
    SAIF information available on the net.

2)  You can join the SAIF Mailing List which will keep you up-to-date
    with announcements and developments pertaining to SAIF.  Send an
    email to "[email-masked]" with the subject "SAIF Request" to be
    added to the list.

3)  You can FTP the SAIF 3.1 specification, print it out, and read it.
    See Q7.

4)  You can use physical mail and contact:

        SAIF Info,
        Surveys and Resource Mapping Branch, 
        B.C. Ministry of Environment, Lands and Parks,
        Fourth Floor, 1802 Douglas Street, 
        Victoria, BC  CANADA V8V 1X4
        Tel: (604) 387-1353
        Fax: (604) 356-7831

5)  You can order a hard copy of the SAIF 3.1 specification (price approx 
    CDN$20/copy) by contacting:

          MAPSBC
          Surveys and Resource Mapping Branch
          B.C. Ministry of Environment, Lands and Parks
          Third Floor, 1802 Douglas Street
          Victoria, BC  CANADA  V8V 1X4
          Tel: (604) 387-1441
          Fax: (604) 387-3022

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Q6: Is the SAIF Specification on the Web?
-----------------------------------------
Yes, a fully hypertexted version of the SAIF specification is available at:

    http://www.wimsey.com/~infosafe/saif/saif31spec.html

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Q7: What FTP sites carry the SAIF Specification document?
---------------------------------------------------------
The SAIF specification is available from the following two FTP sites:

    site:         s2k-ftp.cs.berkeley.edu
    directory:    pub/sequoia/schema/STANDARDS/SAIF
    
    site:         moon.cecer.army.mil
    directory:    ogis/related/SAIF3.1

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Q8: What's the easiest way to get familar with SAIF?
----------------------------------------------------
You should get the SAIF 3.1 specification document (either hardcopy
softcopy, or by browsing the Web).

If you are looking for a very high level understanding of SAIF, read
the Foreward and Section 1.1 only. This amounts to two pages.

If you want a greater degree of familiarity, say something that can be
digested in an hour or so, the following sections are suggested:
1.1, 1.2, 1.3, 2.1, 2.4, 2.5, 2.6, and 4.7. These constitute about 29
pages.

The WWW version of the document has a "quick tour" that will guide you
to these parts.

To come up to speed with the SAIF base set of classes, we recommend you
browse them with a hypertext tool rather than by reading the document.
If you have WWW access, you can do that (see Q6).

For those who do not have Web access, Safe Software is considering
producing a stand-alone Windows 3.1 hypertext version of the
specification and distributing it for a small handling charge.  Send
email to "[email-masked]" if you would be interested.

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Dale Lutz                    Safe Software, Inc                  [email-masked]
                            Richmond, BC, CANADA               (604) 241-4424
                         http://www.wimsey.com/~dal
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