Tag Archives: geonode

Clearinghouse for the environment – the girders (II)

In February 2012 I wrote about “Environmental Spatial Data Infrastructure” on this blog. Later that year the case complex matured somewhat and in August I wrote the posting “Clearinghouse for the environment – the scaffolding (I)“.

Since then I have together with my colleagues had the opportunity to test systems in full scale by contributing to the implementation of clearinghouses in partner countries.

Last time I showed how a stack consisting a hardware layer with vmWare as one of the basic modules could form the basis of an environmental spatial data infrastructure. In some ways this was a rather optimistic setup.

A stack of hardware and software which could become very usefull...

Some of our main challenges with the above set up was maintenance of physical equipment. So we removed that layer. Maintaining a complex setup with a virtual machine environment, or getting access to local environments proved in general to be difficult. So we ditched it.

To get the systems running we needed:

  • Shared access to the systems for administrative purposes
  • A flexible backup-system
  • An option to duplicate successful setups
  • Scalability
  • High availability
  • Flexible security system

Other things we considered important

  • The system should not tie our partners up in future licensing costs
  • Compliance to central standards
  • An option for partners to move the systems to physical infrastructure if necessary
  • Option to keep traffick outside our own company networks – since they are de-facto external systems paid for by external partners

As you all can see in all a lot of considerations which we had to relate to.

AWS_LOGO_CMYK-588x214Since internet access across borders in any case would be relevant for retrieving external map layers we started looking at how we could use Amazon services. I already had experience in running virtual macines using Amazon EC2. Amazon helped us out with many of the issues mentioned above. So in short we moved the whole setup to Amazon. The following figure illustrates the setup.

sdi_onestop_amazon

In addition to the components relying on EC2 we have also found that using Amazon Simple Storage (S3) for storing survey data of some size could be a good ide. S3 allows the user to distribute files using “secure” links and even using the bit-torrent protocol for files up to 5 Gb.

We now have one such system built up and under testing. It looks good but as always the technology is but a small part of the equation. Establishing information flows, using standards etc represents the major parts of a national envoronmental spatial data infrastructure.

Should the need arise to develop custom made solutions it should be possible to add more virtual machines in the setup.

sdi_onestop_amazon

Given that our partners find this setup trustworthy we will probably suggest this as an entry level spatial data infrastructure for environmental data.

WordPress directly, and through countless plugins, supports many standards for embedding information. How information should flow between the different systems in this setup has been given some thought. I will try to elaborate on this in a later posting – hopefully in less than two years time.

Integrating the OGC WMS getcapabilities information in WordPress (iframe)

wms_tools_codeOver the last two years I have worked with WordPress as a content management system for several projects. WordPress has proved to be a flexible platform for publishing documents, files in general, imagery and maps. There was one thing missing though. I wanted to be able to list map layers available on a given wms-server.

To solve this I have now made a small php-script which allows the user to integrate server capabilities information from a geoserver based WMS-server. The code is a work in progress and does admittedly have some shortcomings.

The feature would not be possible without wms-parser.php and Openlayers. Continue reading

Clearinghouse for the environment – the scaffolding (I)

In our work with development cooperation GIS we have come to a point where we find it necessary to establish an overall publication system for environmental information. We will do this together with some of our partners. The system, a clearinghouse, should enable our partners to present project related information to the general public.

A draft system was set up and documented in a former posting on this website. In the article, Environmental Spatial Data Infrastructure – technology, I described the system and some of the challenges. In this article I am taking it a bit further, hoping to stimulate to discussions about how such a system could be implemented.

This posting is about designing a clearinghouse predominantly intended for environmental data. It describes a work in progress. We are working on a requirements document and this posting is ment to inform interested parties about the work. Inputs to our work is both asked for and necessary.

Continue reading

Environmental Spatial Data Infrastructure – technology

Maubissie in Timor-LesteEstablishing the basics for handling environmental spatial data relies on proper organization of the data into repositories where it is stored and prepared for dissemination. This article points to how such a structure could be made using geoserver, geonetwork, WordPress, Geonode, Postgis and Linux. All modules has been chosen because of being open source. As a consequence this constellation is an excellent starting point for establishing thematic data infrastructures in developing countries. As it is, the infrastructure below would not be possible without the support of contributors like the WorldBank and OpenGeo.

Will the suggested infrastructure can do the job. And if it does, how is it used by the human/organisational part of the equation? The answers to latter are beyond the scope of this article. This time I will try to answer the first question – and thus look at the technical sides of it. Continue reading