If I Were a Small City GIS Manager
Posted on January 03, 2012 by Adam Lodge
If I were a small city GIS manager
...I would deploy significant portions of the City's GIS infrastructure using free and Open Source technology. Why?... why not? It's free to procure and provides top notch capabilities. In the absence of specific technological or organizational constraints, here are the components I would use.
Database:
The database would be PostgreSQL with PostGIS. Using PostGIS, anyone with even minimal SQL skills can develop spatial queries, integrate data between GIS and other business systems, and serve data to almost any application tier technology.
Desktop:
I would use Quantum GIS (QGIS) as the desktop GIS technology of choice. QGIS beautifully meets the 80/20 rule for ad-hoc GIS processing and display. Meaning - it has the geo tools required for most any task you throw at it. All it is missing are the obscure tools that rarely get used. (Has anyone ever used "Calculate Distance Band from Neighbor Count"?) The good news is, if I am that guy who needs a custom analytical tool, I could build it in Python (also Open Source), embed the functionality within QGIS, and share it with the QGIS community.
Application Server:
My server GIS would be powered with GeoServer. Nothing makes it easier to transform a table or view in a database into a functional web service ready to be consumed by most any viewer - Google Earth, Open Layers, or even ArcGIS Server.
Presentation Tier:
Lastly, web applications would be built using Open Layers. I'm no web developer, so what makes Open Layers awesome to me is its simplicity. It lets me consume and expose whatever basemap I want. It can be Google Maps, Bing Maps, ArcGIS online, WMS, WFS - you name it, Open Layers can sprinkle your custom data on top of it.
All of this free, enterprise-class capability makes me marvel at the oodles of cash that are blown on proprietary software (and software maintenance) by cash-strapped local governments every day. As a former GIS Manager for San Mateo County, I have to ask what is it that you think keeps cities spending the money? Drop a line if you have any ideas.
Tags:
Open Source
Smartphones, tablets, and GPS accuracy….
Posted on December 20, 2011 by Jeff Smith
I am consistently amazed by the quality of the GPS chipsets present in average smartphones and tablets. Typically these devices give location readings with accuracies of 10 of meters, although under ideal conditions I have seen several Android phones report an accuracy of 2 meters! This is pretty impressive considering that these devices do so much beyond just GPS.
Still it is a fair question to ask, "Can a consumer based smartphone really meet the demands of my organization's spatial problem? Don't we need a more accurate, professional grade device with a high accuracy GPS receiver?". The answer to this really depends on how you intend to apply the spatial data. It's the same question (and answer) that GIS practitioners have been arguing with surveyors about for decades: The higher the level of spatial accuracy you need, the higher your equipment costs are going to be. Thus it is very important to avoid the pitfall of imposing arbitrary data accuracy requirements on a project just because the numbers sound good, and not because they provide any greater business value. Ask yourself; Do you truly need the gold-plated solution to meet your business objective?
Even if you do really need higher spatial accuracy than a standard smartphone or tablet can provide (say for an engineering design project) there are still options for leveraging the user experience provided by modern smartphones and tablets. Recently I worked on a project where the client required 2-5 meter accuracy on the spatial data they were collecting. Fortunately there are several professional grade GPS devices that now run the Android operating system, including the Trimble Nomad. Using these devices allowed us to leverage the Android user interface to create a fast and easy to use application while still meeting the enhanced spatial accuracy requirements of the client.
So what if you need really need survey grade spatial accuracy. Fortunately, there are survey grade GPS receivers like the Trimble Rover which provide a bluetooth interface. Using bluetooth we can create applications that run on a standard smartphone or tablet, but leverage a survey grade GPS sensor on another specialized device. This allows us to take advantage of the benefits provided by modern smartphones and tablets like form factor and intuitive user interfaces, while still meeting the spatial accuracy requirements a project may impose.
Tags:
GPS,
Mobile
eCatch 2.0 - rebuilding sustainable fisheries on the California coast using GIS
Posted on December 16, 2011 by Joe Metro
If you follow environmental news then you probably already read about eCatch, a new iPad app developed by The Nature Conservancy that gives fishermen real-time access to the latest information on where the fish are – the abundant ones they want to catch and the overfished ones they need to avoid.
The basic idea behind eCatch is that some fish are becoming endangered through overfishing, and the best way to mitigate this is to give fisherman as an industry, the tools to manage their fishery sustainably themselves.
Using eCatch, fisherman at sea, report areas where they caught overfished species and learn from other fisherman where the more abundant species are. By collaborating and sharing information in real-time, fisherman can prevent rapid declines in fish populations and rebuild robust fishing industries and communities along California’s Central Coast.
eCatch 1.0 is a web-based application that allows for:
- Visualizing the locations of catches for a variety of fishing vessels
- Developing reports that summarize the species and catch from each vessel, and as aggregates for a group of vessels
- Monitoring the progress towards catch limits
- Tracking the capture of depleted species
The results are pretty impressive so far so The Nature Conservancy has engaged Farallon Geographics to help them develop eCatch 2.0.
eCatch 2.0 will introduce significant enhancements to the UI and mapping technology to make accessing and interacting with fisheries data both more dynamic and more intuitive. It will also expand the application so it is useful to managers and administrators as well as fisherman.
Users will be able to query and visualize catch histories in order to predict trends as well as define and view reports and histories on species limits, location and amount of overfished species taken for a given time period for individual vessels and aggregated by associations.
Some specifics:
- Fishermen will be able to see on a Google basemap of the central California coast, locations where overfished species have been caught from their vessel, as well as any other vessel.
- Fishermen will be able to display any portion of their fishing history on the map by indicating the time span and species caught.
- Managers and Administrators will be able to link to a form that allows for editing logbook data simply by clicking on a set point.
- The application will alert users when an overfished species catch event happens as soon as the data are entered into the system
Farallon is working with the Nature Conservancy on a set of web services for geospatial data access and reporting using Microsoft .NET web framework along with PostGIS/PostgreSQL, ESRI SDE, ESRI ArcGIS Server, ExtJS, and OpenLayers.
eCatch 2.0 is expected to go public sometime this year.
Tags:
Asset Management,
Database,
ESRI,
Open Source,
Sustainability
Google Maps V3 45 Degree Imagery in OpenLayers
Posted on October 20, 2011 by Rob Gaston
Using the OpenLayers 2.11 with Google Maps API V3 provides some great new functionality that will lead most users to want to upgrade their existing mapping applications. Not only do you get the latest functionality and imagery from Google Maps, but it also simplifies deployment of your application by eliminating the need for managing API keys.
However, there is a minor ‘gotcha’ in this latest version of the Google Maps API that could cause certain developers a lot of grief which OpenLayers 2.11 will not handle by default. In certain locations, Google Maps API V3 now provides access to 45 degree satellite imagery. “Great!,” you say, but not so fast. The imagery only shows up in certain locations and at certain zoom levels. What’s more, if you don’t specifically disable it, you will always get the 45 degree version of the imagery if it is available. This can create a pretty disjointed user experience when navigating the map, but more importantly it causes any 2D vector layers which you are overlaying on your map to appear improperly registered against the base imagery.
Luckily there is a solution to this issue that is fairly simple to implement. Whenever you add a Google Maps layer to your OpenLayers map, it adds a reference to the Google Maps mapObject that it is using to request the Google Maps imagery. By calling the setTilt method on the map object, we can disable 45 degree imagery for all Google Maps layers, like so:
googleMapsLayer.mapObject.setTilt(0);
Just ensure that this call is deferred until after the layer is added to your map, and you should never see the 45 degree imagery in any of your Google Maps layers.
Tags:
Web Mapping
