[OKGIS] Streaming map data services for Arkansas. Oklahoma?

Mon Mar 17 20:10:46 CST 2008

David,

Free data, maintained by others, provided in real time is awesome - until
all the servers are down because of a natural disaster ;).  That's mostly a
joke; I am not much of a fear monger. But, I would at least argue that
maintaining the ability to download the data is important.

I actually believe the opposite of what you said about size. If it is too
big then that IS the time to serve it up - case in point - raster layers.
Can you imagine every state agency housing a copy of 1' color
orthophotography for the state?! As a taxpayer I would be outraged - that's
a LOT of storage.

On your point about scale dependant layers, if you are talking image service
then the size of the output image has much more to do with the number of
pixels than how many features or layers are turned on. If you are talking
data service then I guess I agree, though part of providing a data service
has to do with (like you said) putting more control in the client's hands -
meaning you might not want to limit a layer by scale.

As far as the Arkansas data being the first useful service, I have a couple
of points:

First, every (yes every) layer in the National Map (nationalmap.gov) is -
because of the nature of the National Map - an image service. Here are just
the ones for Oklahoma:
http://nmcatalog.usgs.gov/catrepjsf/faces/partners_data.jspx. The US map of
partnerships is here:
http://nmcatalog.usgs.gov/catrepjsf/faces/partners_data.jspx. 

Additionally, a very smart man at another highly developed state's data
warehouse wrote an ingenious application called Mapdex (www.mapdex.org
<http://www.mapdex.org/> ) before being hired by the big boys. He found a
way to index publicly accessible ArcIMS servers. For example, if you search
for 'oklahoma' in the layers search you get this page
(http://www.mapdex.org/search/search.cfm?layerkeyword=oklahoma
<http://www.mapdex.org/search/search.cfm?layerkeyword=oklahoma&tab=lyr&type=
lyr> &tab=lyr&type=lyr) where you can see 4-5 different services offering
the mar_2002 Oklahoma City aerials. You should play around with it - its
pretty amazing.

David Lowther

  _____  

From: okgis-bounces at gis.gis.ou.edu [mailto:okgis-bounces at gis.gis.ou.edu] On
Behalf Of David W. Wheelock
Sent: Monday, March 17, 2008 5:49 PM
To: Oklahoma GIS Community
Subject: RE: [OKGIS] Streaming map data services for Arkansas. Oklahoma?

Hi David,

I'm all about free data, maintained by others, provided in real-time so that
I don't have to download and maintain it.

That being said, bandwidth can be an issue.  If it's too large it makes
sense to download it.  However, bandwidth can also be managed with scale
dependent layers, so that you don't pull down too much at once.  It can also
be managed with the ArcGIS map cache (Tools>Options>Data Interopability) and
letting ArcMap cache the downloaded data on your computer.

I use aerial imagery from streaming servers every chance I get.

This Arkansas data is the first useful data services I've found.

There's also a useful nationwide image service from the US Forest Service
called GeoMAC, www.geomac.gov.  It provides lots of base layers.  The
symbology is not the best, but for providing base layers for adjoining
states, it works well.

Cheers,

David

  _____  

From: okgis-bounces at gis.gis.ou.edu [mailto:okgis-bounces at gis.gis.ou.edu] On
Behalf Of David Lowther
Sent: Monday, March 17, 2008 12:22 PM
To: 'Oklahoma GIS Community'
Subject: RE: [OKGIS] Streaming map data services for Arkansas. Oklahoma?

David,

Shelby, Learon, and crew in Arkansas are rocking these days. But, I have to
point out that (as you mention) the OK Data Warehouse Mapper has been
providing WMS (image service) for over 5 years, and enabling WFS (data
service) would be a minor enhancement.  Back in the day, the decision was
made not to provide data services via the OK Data Warehouse Mapper because
of bandwidth and server horsepower constraints. Additionally, the people
using the OK Data Warehouse preferred (no, we didn't ask them ALL) to
download and lay hands on the data they were using. 

Of course, times have changed.

One of the main issues that I brought up (and I believe you chimed in!)
during the statewide "needs assessment" performed via the NSDI grant to the
GIS Council was that of data services. Are they a good idea? Would they be
used? Are they a priority? Statistics in Arkansas clearly show they are
used. The good idea is debatable, but I say if the bandwidth and horsepower
are there then there is not a lot to lose. Another issue is: what flavor of
data service should be provided? Obviously the primary client to these
services is an ArcGIS desktop product. While ArcGIS does provide support for
WMS and WFS (the OGC standards) it is clear that ESRI map services are
better supported within ESRI products.

I'd love to hear from others on what they think. 

Do you currently use any image or data services? (On your desktop? In your
web GIS?)

Do you desire data services over image services?

Is the notion of service over download at all appealing?

If you are / would be a data provider, do you have issues with sharing your
data as a data service (where you have no say over symbology) over an image
service (where you have complete control)?

Interesting topic, David. Thanks for bringing it up!

David Lowther

  _____  

size=2 width="100%" align=center tabIndex=-1> 

From: okgis-bounces at gis.gis.ou.edu [mailto:okgis-bounces at gis.gis.ou.edu] On
Behalf Of David W. Wheelock
Sent: Monday, March 17, 2008 12:29 PM
To: Oklahoma GIS Community
Subject: [OKGIS] Streaming map data services for Arkansas. Oklahoma?

Hi folks, 

I've discovered that Arkansas appears to be setting the standard for data
access in this region.  In addition to their data download that they've had
for a few years, like Oklahoma,
<http://www.geostor.arkansas.gov/Portal/index.jsp>
http://www.geostor.arkansas.gov/Portal/index.jsp, they're now streaming data
in ArcIMS as a Data Service, not just as an Image Service.  This means you
can load individual layers of Arkansas data directly into your map and
symbolize it however you'd like without having to download it to your
computer.

See here for instructions: 

<http://www.geostor.arkansas.gov/Portal/htm/map_services_help/map_service_ac
cess.html>
http://www.geostor.arkansas.gov/Portal/htm/map_services_help/map_service_acc
ess.html 

I thought OU CSA had an image service as a WMS service, but I haven't been
able to find it.  Does CSA currently have an image or data service for its
data?

Thanks, 
David 

David Wheelock     Application Specialist     david at oda.state.ok.us 

Oklahoma Department of Agriculture, Food and Forestry
2800 North Lincoln Boulevard
Oklahoma City, OK 73105-4298
Phone: (405) 522-5477 FAX: (405) 522-3590
 <http://www.oda.state.ok.us> http://www.oda.state.ok.us 

"We are usually convinced more easily by reasons we have found ourselves, 
than by those which have occurred to others." 
 <http://en.wikipedia.org/wiki/Blaise_Pascal> Pascal 

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