Design of the front end electronics for the infrared camera of JEM-EUSO, and manufacturing and verification of the prototype model

Abstract

The Japanese Experiment Module (JEM) Extreme Universe Space Observatory (EUSO) will be launched and attached to the Japanese module of the International Space Station (ISS). Its aim is to observe UV photon tracks produced by ultra-high energy cosmic rays developing in the atmosphere and producing extensive air showers.The key element of the instrument is a very wide-field, very fast, large-lense telescope that can detect extreme energy particles with energy above 10 19 eV. The Atmospheric Monitoring System (AMS), comprising, among others, the Infrared Camera (IRCAM), which is the Spanish contribution, plays a fundamental role in the understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. It is used to detect the temperature of clouds and to obtain the cloud coverage and cloud top altitude during the observation period of the JEM-EUSO main instrument.SENER is responsible for the preliminary design of the Front End Electronics (FEE) of the Infrared Camera, based on an uncooled microbolometer, and the manufacturing and verification of the prototype model. This paper describes the flight design drivers and key factors to achieve the target features, namely, detector biasing with electrical noise better than 100µV from 1 Hz to 10 MHz, temperature control of the microbolometer, from 10• C to 40 • C with stability better than 10 mK over 4.8 hours, low noise high bandwidth amplifier adaptation of the microbolometer output to differential input before analog to digital conversion, housekeeping generation, microbolometer control, and image accumulation for noise reduction.It also shows the modifications implemented in the FEE prototype design to perform a tradeoff of different technologies, such as the convenience of using linear or switched regulation for the temperature control, the possibility to check the camera performances when both microbolometer and analog electronics are moved further away from the power and digital electronics, and the addition of switching regulators to demonstrate the design is immune to the electrical noise the switching converters introduce.Finally, the results obtained during the verification phase are presented: FEE limitations, verification results, including FEE noise for each channel and its equivalent NETD and microbolometer temperature stability achieved, technologies trade-off, lessons learnt, and design improvement to implement in future project phases.

Microbolometer characterization with the electronics prototype of the IRCAM for the JEM-EUSO mission

“…Both parts are electrically isolated in the PCB and can be connected by a harness simulating the flex connector in the flight design or by direct electrical connections using jumpers. Further details about the design, implementation and tests of the prototype are included in [10] . Figure 7 depicts the FEEP.…”

Design and characterization of the optics and microbolometer electronics breadboard of the infrared camera for JEM-EUSO

“…Both parts are electrically isolated in the PCB and can be connected by a harness simulating the flex connector in the flight design, or by direct electrical connections using jumpers. Further details about the design and implementation of the prototype are included in [10]. Fig.…”