The data layer is a MySQL database provided by Google Cloud SQL.
Instructions for how to connect to the data layer using a MySQL client are here (archived versions here).
There exist some specialized APIs that can be used to obtain data-layer-level data for specific purposes:
A description of the database table and field structure is here.
A list of useful SQL queries is here.
The middle layer consists of several “calculation services,” which are basically bits of code that do calculations of some sort. They are structured as “web services” that receive an HTTP request, which is the protocol that a standard web browser uses to request web pages from a server, but can also be used by almost any programming language or computational environment. The service returns results formatted in a way that can be read by the requesting program. For a web browser, this would be HTML-formatted text as normally used for web pages. For other software that is interested in using the numerical results rather than displaying the web page, the response is text that is formatted in a data encoding standard such as XML that can be easily read by software.
At the moment, the only middle-layer calculation service available to the ICE-D project is provided by the online exposure age calculators that have been in existence since about 2007 and are familiar to most researchers involved in cosmogenic-nuclide geochemistry. These run on servers at http://hess.ess.washington.edu and http://stoneage.ice-d.org. These are most commonly used by interacting with them using a web browser, in which a user enters text into a webpage, submits it to the server, and receives in response another webpage containing numerical results. However, they can also be used programmatically as a web service. How to do this is explained on this page.
There are no others at the moment. We plan to have a workshop on how to make one.
An “analysis layer” is a layer that obtains information from the data layer and the analysis layer and displays or uses it in some way.
The ICE-D web server is an example of an analysis layer application. Mostly, the purpose of this application is to display information to a user via a web browser, but there are a couple of tricks embedded in the web page that allow one to also use this application to get information in a form that can be easily used by software. This is explained here.
An ICE-D WFS service enables desktop GIS software (ArcGIS, QGIS, etc.) to display and work with exposure-age data from ICE-D applications.
Details about the WFS and how to connect to it are here.
Information about ARC/QGIS toolboxes and applications is here.
The web server code also can serve ICE-D data in a georeferenced form that can be used by web mapping applications. Some examples and instructions for how to do this are here.