Thanks for the link to the book Brent (Fraser). I'll check it out and
add a link to it on my blog.

You raised an interesting concept that I didn't think of before:

"Another interesting problem (and potential more difficult)
is tracing the lineage of an object (historical-style
relationships such as "was-created-from" and "became", etc)."

Perhaps an example of this that applies to my data model would be a
Coordinate feature that results from or was created from a Control Tie.
But things could get complicated fairly quickly. A Coordinate in this
context is actually the result of a Control Tie and a Network
Adjustment.

Brent (Pedersen) also mentioned a concept that I hadn't thought of. He
wrapped my Monument events in a "history" object. I hadn't thought of
linking events in this way.

You guys have given me some great stuff to chew on. I know there will be
some challenges, but I definitely plan on incorporating temporal data
into my data model and I will incorporate both your suggestion and Brent
Pedersen's into my work.

Thanks very much for taking the time to discuss this.

Landon

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Brent Fraser
Sent: Thursday, December 13, 2007 3:09 PM
To: [email protected]
Subject: Re: [Geowanking] Time In GIS

Landon,

  You could have a look at Gail Langran's book:

Langran, Gail (1992): Time in Geographic Information Systems


    As Brent Pederson points out, it can be as simple as a
table join once you've decided which objects you are going
to model and which events are important to those objects.

  Another interesting problem (and potential more difficult)
is tracing the lineage of an object (historical-style
relationships such as "was-created-from" and "became", etc).

Brent Fraser
GeoAnalytic Inc.
Calgary, Alberta

----- Original Message ----- 
From: "Landon Blake" <[EMAIL PROTECTED]>
To: <[email protected]>; "OSGeo Discussions"
<[EMAIL PROTECTED]>
Sent: Thursday, December 13, 2007 1:48 PM
Subject: [Geowanking] Time In GIS


This is being sent to the geowanking and OSGEO discuss list.
I apologize
in advance if you catch it in your inbox twice, but I didn't
want to
miss any potential resources.



I'm working on a GIS Data Model in which I am trying to
model some
temporal data. I've done a little research online, but most
of the info
is pretty ESRI specific. Although I'm somewhat curious about
the use of
temporal data in a GIS in general, I'm really interested in
a specific
approach to the problem.



Does anyone know if there is material available that
discusses using
events to model temporal data? (Like the "events" we use in
GUI
programming.)



I'd really like to read some "software-neutral" principles
on how events
can be used to model time in GIS if this is available. Or,
if you have
tackled this challenge personally, I'd love to learn more
about your
personal experience and solutions.



Thanks,



Landon (A.K.A. - The Sunburned Surveyor)



P.S. - I posted about the particular circumstances that led
to my
interest in this topic and some existing material I found
online at my
OpenJUMP blog: http://openjump.blogspot.com/





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