Cosmic ray oriented performance studies for the JEM-EUSO first level trigger

Abstract

JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 · 10 19 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light 5 conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics.

EUSO-SPB1 Mission and Science

“…The DC coupling permits, for example, photometric calibrations using pulsed and DC light sources and direct measurements of background light levels. The on-board trigger system [20,21] operates at the MAPMT level and looks for locally persistent signals above background within 3×3 pixel cells. The local background threshold is adjusted…”

The trigger logic of EUSO-SPB and its performance

“…The FLT logic and first tests are described in [2]. The FLT rejects most of the fluctuations of the UV night-glow as well as electronic noise by requiring a locally persistent signal that lasts a few GTUs above the average background.…”

“…Most of them were successfully downloaded on ground and are being processed. EUSO-SPB mounted on-board an autonomous First Level Trigger (FLT) similar to the one foreseen for JEM-EUSO [2]. Prior to its flight, EUSO-SPB was tested on a ground campaign in Utah, at the TA-EUSO [3] site where the detector was exposed to the night sky luminosity and to a variety of point-like and diffused light sources such as stars, meteors, airplanes and lightnings with the aim of understanding its performance.…”

Studies on Cup Anemometer Performances Carried out at IDR/UPM Institute. Past and Present Research

“…The line of work related to wind speed sensors calibration represents, together with space engineering [1][2][3][4][5][6][7][8][9][10][11], wind engineering [12][13][14][15][16][17], and different high education degree programs such as the Master in Space Systems [18][19][20][21], the core of the activities being carried out by the IDR/UPM research institute's staff.…”