History and archeology meet GIS! Azavea and Integrated Conservation Resources partnered to create Sandstone, a desktop software application for cataloging the condition of important buildings and other historically significant structures in need of architectural conservation, for the World Monuments Fund (WMF).

The software is designed to enable conservators to easily capture notes and drawings while using a stylus on a tablet PC in the field. Users can draw objects or conditions using points, lines and polygons on top of an image, CAD drawing or shapefile while being disconnected and then synchronize the changes from many tablets to a single central server later on. They can also perform queries across an entire site, fill out a form representing metadata while each feature (object or condition) automatically calculates a length, perimeter and area, as necessary.

The World Monuments Fund is a non-profit organization dedicated to the conservation of the world’s cultural heritage. At any given time they manage approximately 150 preservation projects worldwide, and employ hundreds of conservationists who rub elbows with 300-year old painted ceilings in Paris, catalog rain damage during monsoon season in Cambodia, or conserve a fourth century Roman emperor’s “retirement home”. The projects are spread out in locations across the world where the conservators work in challenging climates, on delicate and historic sites. As an organization that has dedicated itself to reviving and documenting ancient techniques of building and artistry, they also must seek out the best and most recent tools and technology in order to meet their goals.

Example of how Sandstone can be used – Angkor Wat, Cambodia. Background Photo Copyright: © 2009 Google – Imagery ©2009 DigitalGlobe, GeoEye

Before any actual restoration can begin on a project, a very detailed and thorough survey of the site is often needed to complete preliminary plans. Using special software, one or more conservationists may spend weeks cataloging every last crack or blemish across a massive site.

To tackle the challenge of coordinating survey efforts across different countries, people, and databases, some serious creativity was required. For starters the new software needed to reorganize itself ‘on the fly’; any site might require a totally different range of data, so we built a dynamic data model and a flexible user interface. With their work spread across fragile hardware in a potentially harsh environment, the next challenge was protecting their efforts. Since distributed database sharing wasn’t an option, we needed to create a way to maintain synchrony in a situation where multiple users may all be editing the same bit of information without a server to keep it all in line. All of this while in the field without an internet connection, and without a server room standing by. This led to the creation of a peer-to-peer network design and versioning model using the JXTA library, and an idea called a Lamport clock to keep the data consistent. JXTA was only one of the many open source tools used to create Sandstone. The World Monuments Fund hopes to eventually make the software available as an open source toolkit, so in addition to JXTA, it builds on existing open source tools such as uDig, Postgre SQL and Eclipse.

The Sandstone software is currently being used at the Church of Saint Trophime in Arles in the south of France. We brushed up our French, revised verb conjugations and their impossible pronunciation — come on! how do you even start saying “ils aillent”? — in the hope we might have to travel there. Mais non! Ah! C’est la vie … In any case, it was richly rewarding to learn from and use these tools, and to hopefully contribute back into them as the project continues. We’re hoping that over time we will be able to shape this project into something that might benefit even more users worldwide. We have just finished Phase I of the project. The World Monuments Fund hopes to make an official release of Sandstone after Phase II had been completed.