The digital data processing concepts of the LOFT mission

TL;DR

This paper discusses the data processing concepts for the LOFT mission, focusing on handling large data rates from X-ray detectors with real-time filtering, compression, and source localization algorithms.

Contribution

It provides an overview of the data handling strategies developed for LOFT's instruments, highlighting real-time processing and algorithmic approaches for X-ray data analysis.

Findings

Design of real-time data filtering and compression for LAD

Algorithms for photon interaction localization in WFM

Efficient data handling concepts for high data rate X-ray observations

Abstract

The Large Observatory for X-ray Timing (LOFT) is one of the five mission candidates that were considered by ESA for an M3 mission (with a launch opportunity in 2022 - 2024). LOFT features two instruments: the Large Area Detector (LAD) and the Wide Field Monitor (WFM). The LAD is a 10 m 2 -class instrument with approximately 15 times the collecting area of the largest timing mission so far (RXTE) for the first time combined with CCD-class spectral resolution. The WFM will continuously monitor the sky and recognise changes in source states, detect transient and bursting phenomena and will allow the mission to respond to this. Observing the brightest X-ray sources with the effective area of the LAD leads to enormous data rates that need to be processed on several levels, filtered and compressed in real-time already on board. The WFM data processing on the other hand puts rather low constraints on the data rate but requires algorithms to find the photon interaction location on the detector and then to deconvolve the detector image in order to obtain the sky coordinates of observed transient sources. In the following, we want to give an overview of the data handling concepts that were developed during the study phase.