The data handling system for the AGILE satellite

Abstract

AGILE, Astrorivelatore Gamma ad Immagini LEggero, is a small space mission of the Italian Space Agency (ASI) devoted to observations for astrophysics in the gamma ray energy range 30MeV-50GeV with a simultaneous window in the X-ray band 15keV-45keV. AGILE Payload is composed by four scientific detectors: a Tungsten-Silicon Tracker, a CsI MiniCalorimeter, a Silicon based X-ray imager and an anticoincidence system for particle background rejection. Moreover, the Payload is completed by a Power Supply Unit (PSU) and a Payload Data Handling Unit (PDHU) and by three ancillary sub-systems (a GPS receiver and two Star Sensors). The PDHU tasks are: the Payload scientific and ancillary sub-systems control, the operational modes management, the scientific data processing and the Telemetry and Telecommands management. The scientific data processing involves the gamma-ray photons filtering, the X-ray data acquisition and a Burst acquisition logic able to perform an on-board Burst coordinates determination. The HW and SW design and implementation is in charge of the Alenia Spazio S.p.A. -Laben. In this paper we present a general description of the PDHU and the guidelines for the scientific simulations and the HW and SW testing activities.

Properties of terrestrial gamma ray flashes detected by AGILE MCAL below 30 MeV

“…The AGILE payload is composed of a tungsten-silicon tracker (ST) [Prest et al, 2003], for gamma-ray imaging in the energy range 30 MeV -30 GeV; a silicon based X-ray detector, SuperAGILE (SA) [Feroci et al, 2007], for imaging in the range 18 keV -60 keV; a CsI(Tl) mini-calorimeter (MCAL) [Labanti et al, 2009] for the detection of gamma-rays in the range Journal of Geophysical Research: Space Physics 10.1002/2013JA019301 300 keV -100 MeV; and an anticoincidence (AC) system [Perotti et al, 2006] made with plastic scintillator layers for the rejection of charged particles. The scientific payload is completed by the Payload Data Handling Unit (PDHU) [Argan et al, 2004] that takes care of data acquisition of the various detectors. ST and MCAL form the Gamma-Ray Imaging Detector (GRID) for observations in the energy range 30 MeV-30 GeV.…”

The AIV quick look and health monitoring system of the AGILE payload

“…A cluster is a set of contiguous readout strips that have passed the trigger logic implemented into the PDHU. 8 For each cluster the telemetry contains: e the extra fired chip index: for each view of the Silicon Tracker the max number of triggered chips that are acquired is 8. If more than 8 chips triggers, only the index of the additional triggered chips are sent to ground with the telemetry.…”

“…The instrument is surrounded by an anti-coincidence (AC) system, 7 made by plastic scintillator layers for the rejection of charged particles. These detector subsystems are controlled by the Payload Data Handling Unit (PDHU), 8 which interfaces their analogue and digital front ends in order to perform all the required signal and data on-board processing and generate the Payload telemetry. In turn, the PDHU interfaces the Satellite Data Handling (called On-Board Data Handling, OBDH) in order to transmit the payload telemetry data and receive the payload telecommand data.…”

In-flight performance of the AGILE mini-calorimeter and its gamma-ray burst detection capabilities

“…The instrument is surrounded by an anti-coincidence (AC) system, 8 made with plastic scintillator layers, for the rejection of charged particles and is completed by the Payload Data Handling Unit (PDHU). 9 AGILE was succesfully launched on April 23 2007 from Satish Dawan Space Centre (India) on a PSLV-C8 rocket. The AGILE orbit is quasi-equatorial, with an inclination of 2.5 degrees from the Equator and average altitude of 535 km.…”