ATHENA/WFI Instrument Application Software Definition

Short Description

Starting point / motivation

ATHENA is an ESA L-class mission currently undergoing the definition phase B1. It is an X-ray observatory mission selected within ESA's Cosmic Vision programme, to address the Hot and Energetic Universe scientific theme. Its launch is foreseen for the early 2030s.

ATHENA will consist of a single large-aperture X-ray telescope, utilizing a novel technology developed in Europe, with 12m focal length and 5 arcsecond angular resolution. The focal plane contains two instruments. One is the Wide Field Imager (WFI) providing sensitive wide field imaging and spectroscopy and high count-rate capability. The other one is the X-ray Integral Field Unit (X-IFU) delivering spatially resolved high-resolution spectroscopy over a limited field of view.

The Wide Field Imager (WFI) is based on DEPFET (depleted p-channel field-effect transistor) technology. This kind of device provides almost Fano-noise-limited energy resolution and minimal sensitivity to radiation damage. Because each pixel is addressed individually, readout modes can be highly flexible and extremely fast. The large field of view is achieved with a focal plane composed of several chips, where one of them will enable fast readout to accommodate measurements of very bright targets.

A complex instrument like the WFI needs to be controlled by a powerful computer. This is the Central Processing Module (CPM). Aside from instrument control and monitoring tasks, the science data are processed and compressed for lossless transmission to Earth. This is accomplished by the Instrument Application Software (IASW), which is developed by us at the University of Vienna.

Contents and goals

The proposed project allows us to carry out the work to complete the definition phase B of the ATHENA WFI IASW. Two payload reviews, the iSRR and the iPDR are covered by the project period. Our contribution to ATHENA is a key component in the overall mission design. It is being developed as a fully-fledged ECSS application software which carries out instrument control and on-board science data processing tasks.


The main task of the proposed work is the preparation of the review data packs for the IASW. The primary components of this work package are the software tailoring document, the requirements specification document, the architectural design document, TM/TC ICD, PA plan and application software test plan. These are accompanied by additional documents, such as the software reuse file, the schedulability analysis and technical notes about the implemented algorithms.

Towards the end of the definition phase, a first version of the IASW will be deployed to support interface tests with the spacecraft platform and early EMC tests.

Project Partners


University of Vienna

Contact Address

University of Vienna
Universitätsring 1
A-1010 Vienna