The European reference radiative transfer model was renamed as Eradiate. Information and news about the model are available at In this post, we summarise the requirements elicitation process and give a brief overview of ongoing activities.

A part of the activities taking place in the framework of MetEOC-3 consists in laying foundations for the development of a next-generation radiative transfer model to support calibration/validation activities. Initially simply named ER2TM, as in European reference radiative transfer model, this software package is meant to provide a reliable, extendable and comprehensive framework for radiative transfer simulation.

A new name, a new website

In June 2018, the ER2TM was renamed Eradiate. This uncommon word, which has the same meaning at ‘radiate’, brings a more distinctive identity to the radiative transfer code. In addition to this rebranding, a website was launched at The latest news on development, events, and all the material related with the radiative transfer model will be published there.

Our design approach

Eradiate, despite being research-oriented, was not born just like any other research software project. Many pieces of scientific software are developed as a means to achieve a main research goal: the ‘product’ is the outcome of the research, and the software is just a means of achieving it. In contrast, the development of Eradiate is a goal in itself: the resulting software package is a product.

This simple statement has broad implications in terms of user base, development practices, quality control and many other things, among which the most fundamental one is the design approach. Eradiate being a product, it needs to be designed as such. Following engineering practices, one of the first things to do is to identify product users, and understand their requirements.

Understanding our users

Of course, when the idea of writing a new radiative transfer model came up, potential users were at least partially identified. Work started back in 2016 with a few brainstorming sessions between a few people who wanted to bring together the advances made in Earth observation scientific subcommunities. In late 2017, MetEOC-3 started and Rayference was tasked to assess user requirements for Eradiate.

A community user workshop was held on April 23rd-24th in the JRC facilities of Ispra (Italy), during which 20 potential users of Eradiate presented their work and explained how they use radiative transfer models. Attendees were coming from the various Earth observation European subcommunities: atmospheric sciences, lands, ocean color; but also from the metrology and planetology communities. During the workshop, Eradiate developers presented the ideas they had come up with on how the software package should be structured to improve cross-community knowledge exchange, secure future maintenance and open the doors to improving and extending the model with minimal development costs. This workshop was a rare opportunity to discover common views and differences between scientific communities and yielded valuable information for user requirements assessment.

From these discussions, follow-up correspondance between workshop attendees and developers, the outcome of previous small-size brainstorming sessions and a literature review, an analysis of user requirements was produced and reported in the first issue of the User Requirements document (see the docs section on the Eradiate website). This document, which contains a list of 120 requirements identified by developers, is meant to be used as a base for the general design phase.

What is next?

Now that we know who our users are and what they need, we can proceed with the general design of Eradiate. In this phase we will define the general structure of the software package, the underlying principles of the application programming interface, and the main logical entities and data manipulated by the algorithms. This step of the design process is essential to ensuring that we meet user requirements; it is also critical as an ill-designed software package can have prohibiting maintenance or upgrade costs.

The results of the general design phase will be released in the General Design document, also as part of the radiative modelling work carried out in the framework of MetEOC-3.