Aug
6
A day with TileCache: generating KML Super-Overlays
Filed on August 6th, 2008 at 12:55 pm under Apache, devs, FeatureServer, GDAL, GeoServer, GIS, kml, MapServer, MetaCarta, OpenLayers, Python, SharpMap, TileCache, TMS, Tutorials, WMS | 6 Comments
My friend Diego Guidi is the smartest GIS/.NET developer I personally know here in Italy. He is the developer of NetTopologySuite, the port in the .NET world of the popular Java's JTS Topology Suite from VIVID Solutions. I wanted, sooner or later, write some stuff here about WMS and TMS, and now I am very happy that Diego asked me to publish this brilliant article about this topic.
First of all, let me thanks Paolo for hosting this post! I hope that this article can be interesting and useful like other stuff that you can find here…
Introduction
There are a lot of discussions out there about how to define Google Earth, Google Maps, and related apps… are they GIS? Viewers? Video games? Even a neologism was created: Neogeography. I think that all the folks out there have the same idea in mind: maybe Google don't make the same business as ESRI, but Google Earth is cool, and it's funny to play with it!
Jun
6
Spatial Database for Postgres and ArcGis users: how to choose
Filed on June 6th, 2008 at 5:45 pm under ArcGis Desktop, ArcIMS, ArcObjects, ArcSde, FeatureServer, GeoServer, GIS, gvSIG, PostGIS, QGIS, uDig, ZigGis | 13 Comments
As many of you can have already read, ArcSde for Postgres is coming out at ArcGis 9.3 (it is currently in the release candidate state). It will let you store geometries in two formats, Esri geometry and PostGis geometry, in the same fashion ArcSde for Oracle is letting Esri or Oracle geometries be stored.
I have seen some interest in the GIS community about this new, and i was reading interesting posts by Bill Dollins, Paul Ramsey, James Fee and Dave Bouwman, so I thought i would post here my opinion. Plus, as some of you may already know, zigGis 2.0 is out, so I am very interested in understanding where it would be better to use one (ArcSde) or the other (zigGis 2.0) solution.
First let me introduce you my point of view: i am since the ARC/INFO era a great fan of Esri software, and I am one of the many users in the GIS community saying that Esri is much much better vs Open Source in the GIS desktop products sector.
In fact, while also in the GIS OS scenario there are good products like QGIS, uDig, gvSIG (and some other), in my opinion no one of them still can even fairly reach what ArcGis Desktop and its extensions can actually do (with the big limit that you can use it only in a Microsoft box, but that is another story).
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May
3
A day with FeatureServer #2
Filed on May 3rd, 2008 at 2:13 am under devs, FeatureServer, Flickr, GIS, OpenLayers, OpenStreetMap, PostGIS, Python, Twitter, Ubuntu, Web2.0, WFS, Windows, WMS | 4 Comments
In the previous post we have seen an introduction to FeatureServer, and we were just playing with the base edit sample, with the scribble layer.
Now it is time to use FeatureServer with our datasets: I am assuming that you will want to create FeatureServer services for shapefiles, PostGis layers, OpenStreetMap, Twitter and Flickr.
Feb
29
Do you get errors in the mapscript c# tutorial?…
Filed on February 29th, 2008 at 9:48 pm under .NET, devs, GIS, MapServer, PostGIS, Tutorials, Windows | 11 Comments
…well, this is the solution to your problems (at least I hope so).
I am continuing receiving emails from people in despair that cannot successfully use this tutorial. I am sorry but I cannot answer to all this emails, so I thought to write this post in order to allow people to configure it correctly.
BTW, this demo is still working since 2 years without any problems, and the code there is just the same you can download from this blog. So it must work also for you
So if you just cannot use it, this is a check list:
If you receive the "Unable to load dll (mapscript)" error, look at this article from Tamas Szekeres (the mapscript c# mantainer).
Feb
21
A day with FeatureServer #1
Filed on February 21st, 2008 at 10:10 pm under Apache, devs, FeatureServer, GIS, gvSIG, PostGIS, Python, QGIS, Ubuntu, uDig, WFS, Windows, WMS | 6 Comments
Some friends already spoke me well about FeatureServer by MetaCarta in the last weeks, so I already was waiting for having a bit of time to get started with it. Then James posted this on his blog, and my curiosity was definitely fired.
So I decided to spend a day for installing and testing it, without thinking of the lack of documentation (FeatureServer is still a young project, so no wonder here if the only way to get infos is digging in the source code and posting to the mailing list). The day I considered to spend on it then spawned to more and more hours that I could imagine, and given my actually very busy schedule at my job, I had to find free hours during the night and the weekend. I then decided to write this post to help people in getting started with FeatureServer in a quicker way that was for me.
FeatureServer is a simple and powerfull RESTful-Pythonic WFS server.
Only from this last sentence there are 3 very important things that made me like (and you should - also) FeatureServer before even getting started with it:
- Its RESTful architecture
- It is written in Python, and having chosen Plone as our CMS here at my office I am starting to like this language very much
- I truly believe that WFS is the way to go for remotely editing GIS data
Jan
30
Installing PostGIS on Ubuntu
Filed on January 30th, 2008 at 5:29 pm under devs, GIS, gvSIG, PostGIS, QGIS, Ubuntu, uDig | 9 Comments
With this post I will show how to install PostGIS 1.2.1 on Postgres 8.2.5 in Ubuntu 7.10 (but this procedure should work also for previous PostGIS/Postgres/Ubuntu versions) from repositories.
I will also show you how to load and secure GIS data and how to access them with some cool OS GIS Client (QGIS, UDig and gvSIG).
If you use this instructions together with my previous post, you will have a fully functional GIS Server Open Source Ubuntu workstation!
-1- Install Postgres
If you haven't Postgres, you need to install it (PostGIS runs on top of it). Open an Ubuntu terminal, and type:
sudo apt-get install postgresql postgresql-client postgresql-contrib pgadmin3 sudo apt-get install postgresql pgadmin3
Postgres (8.2.5) will be now on your Ubuntu box.
Jan
10
Installing MapServer on Ubuntu
Filed on January 10th, 2008 at 11:51 am under Apache, devs, GIS, MapServer, Ubuntu | 10 Comments
With this post I will show hot to install MapServer 4.10.3 in Ubuntu 7.10 (but this procedure should work also for previous Ubuntu versions) from repositories.
1) set Ubuntu sources needed for this software
Add universe ( http://archive.ubuntu.com/gutsy/universe ) and multiverse repositories to your sources (by default are not in Ubuntu)
sudo gedit /etc/apt/sources.list
and uncomment this two lines:
deb http://archive.ubuntu.com/ubuntu/ gutsy-security main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ gutsy-security main restricted universe multiverse
save the sources.list file and then then update your sources:
sudo apt-get update
Mar
21
zigGis 1.2 released
Filed on March 21st, 2007 at 7:44 pm under ArcGis Desktop, GIS, PostGIS, ZigGis | 7 Comments
zigGIS 1.2, the Open Source ArcGis Desktop's connector to PostGIS, has just been released and you can download it here.

This is a major release, as far it implements new important features like selections and rendering. At this time editing is still not supported (so it is still a read only connector).
Also ArcMap documents persistence is now fully supported, meaning that you can save your mxd document with your PostGIS layer in them, and then open them again without problems.
zigGis should correctly work with ArcGis 9.0 (sp3), 9.1 and 9.2. Before installing it don't forget to install .NET support for ArcGis.

Here is a list of supported and unsupported features in ArcMap with zigGis 1.2:
Feb
21
PostGis WorkspaceFactory
Filed on February 21st, 2007 at 5:58 pm under .NET, ArcGis Desktop, ArcObjects, COM, devs, GIS, PostGIS, ZigGis | 2 Comments
In my previous post I have showed you how to install and using zigGIS for adding PostGIS data into ArcMap.
From the ArcMap user interface you just need to press the zigGIS button and an "Add PostGIS data" dialog will be shown to you. From there you can set a zig File path, where PostGIS connections settings are stored, and then a PostGIS layers list will be shown and you can check which layer(s) add to the map.

In this post I will show how to programmatically use zigGIS and ArcObjects to add PostGIS data into ArcMap.
zigGIS is a Microsoft .NET 2.0 library that can be used from .NET clients and also from COM clients.
You could use it in your ArcObjects .NET applications/library to manage PostGIS data, in any .NET language like VB .NET and C#.
As zigGIS it is obviously exposed to COM (ArcObjects are in COM), you could also use it in your COM applications/library, for example in applications developed with Visual Basic 6 and ArcMap's VBA (Visual Basic for Application).
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Feb
14
Installing zigGIS 1.1 for connecting ArcMap to PostGIS layers
Filed on February 14th, 2007 at 8:04 pm under .NET, ArcGis Desktop, ArcObjects, COM, devs, GIS, PostGIS, ZigGis | 1 Comment
zigGIS is an Open Source PostGIS connector for ArcGIS Desktop, that enables ArcMap to add PostGIS layers in the map.
Differently from other kinds of connectors, like for example PGArc, the very nice feature of zigGIS is the direct-read of PostGIS data, without the needs of proxy shapefiles. This meaning that the PostGIS features are directly readed and displayed in ArcMap from the PostGIS data source without a previous conversion to a shapefile or personal GDB.

This is a very interesting project, but still in a very early phase, in fact there are still important issues that are planned to be solved in the next future, like:
- edit features (edit PostGIS layer from ArcMap is still not implemented, and it is read-only)
- symbology not working (only simple symbol rendering is currently working)
- selections are not supported
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