IEM Access & Free GIS

Daryl Herzmann

Department of Agronomy

Iowa State University

Outline

IEM Background Info

Free GIS components

PostGIS

UofM Mapserver

OpenGIS

IEM GIS Efforts

IEM Access

IEM Overview

Collect, compare, disseminate, and archive environmental data in Iowa

Currently tracking over 650 sites in the Midwest US.

Our goal is to bridge the gap between those that need data and those that have data.

Why GIS?

Provides a framework for data management, analysis and display

Provides a large community of folks able to use GIS datasets

OpenGIS & FreeGIS provides standards to fit our software philosophy

Free GIS

“Free software” is a matter of liberty, not price. To understand the concept, you should think of “free” as in “free speech” or “free markets,” not as in “for free” (gratis).

IEM GIS development fits under the FreeGIS umbrella (software & data)

http://www.freegis.org

'Free' Components

PostgreSQL (Relational Database)

PostGIS (Spatial Blade for PostgreSQL)

UofM Mapserver (Internet Mapping Server)

PHP (Application logic)

Apache (Web Server)

Grass (Desktop GIS)

Proprietary Free

Oracle

ArcSDE

ArcIMS

ASP

Microsoft IIS

ArcGIS

PostgreSQL

PostGIS

Mapserver

PHP

Apache

Grass

IEM Access

Project name for our internal data management system.

'Access' refers to the ability for applications to seamlessly get at these data sources.

At the simplest, it is a publicly available spatial database.

What does IEM Access hold?

Latest observation

Daily Summaries

Monthly Summaries

Growing Season Summaries

Yearly Summaries

Climatologies (soon)

Ex App: Current Sortables

PHP generates a custom view of sites you are interested in

Mapserver can generate a plot of whatever you like.

Ex App: Shapefile download

One-click to download a dynamically generated shapefile with the current conditions in it.

Shown plotted in JUMP (Free GIS)

Other Applications

Give the database your current position and ask for the nearest observation.

Ask the database to take a site observation and compare it to its 10 nearest neighbors. (QC)

Aggregate to some other polygon layer, ex) counties, states

PyIMS Fascade

Allows Mapserver to appear as an ArcIMS service

Homepage: google for 'PyIMS'

Currently only supports RASTER

IEM's PyIMS server is here
db1.mesonet.agron.iastate.edu

Serve nationwide NEXRAD (4326)

Mapserver WMS

First publicly accessible RADAR WMS?

URI:
mesonet.agron.iastate.edu/wms/radar.php?

Currently serves UTM Zone 15 North (epsg: 26915)

Current Challenges

Including time within GIS

Dynamic refreshes with desktop GIS

Inefficiencies of WMS

'Interoperability'

Time for demos?

ArcExplorer

Talk with pyIMS server

Talk with WMS

Ortho server and Mapserver

Website

Current Sortables

Dynamic Plotting

I'm done, questions?

Daryl Herzmann

3010 Agronomy

294-5978

akrherz@iastate.edu

2003-10-21T21:25:52