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Astronomical Data Analysis Software and Systems VII
ASP Conference Series, Vol. 145, 1998
R. Albrecht, R. N. Hook and H. A. Bushouse, e
Ö Copyright 1998 Astronomical Society of the Pacific. All rights reserved.
ds.
The Ground Support Facilities for the BeppoSAX Mission
Loredana Bruca, Milvia Capalbi and Alessandro Coletta
Telespazio, Via Corcolle 19, I­00133 Roma Italy
Abstract. The BeppoSAX ``Satellite per Astronomia X'', a program
of the Italian (ASI) and the Netherlands (NIVR) Space Agencies, was
launched on April 30th into a circular orbit of 590 km altitude and 3.9
degrees inclination.
The Ground Support System components are presented in order
to highlight the end­to­end operation approach to the scientific mis­
sion. The software systems are described following the forward and back­
ward data flow to/from the satellite: starting from the Observation Pro­
posal reception and archiving, the long term observation scheduling up to
the detailed weekly planning and telecommands sequence uplinking, and
vice versa the scientific and housekeeping raw telemetry acquisition and
archiving, quick look data analysis, data reformatting and distribution as
a Final Observation Tape to the Observation Proposal PI. Among these
components the Quick­look Data Analysis system is emphasized. The
main tasks of this system are both health monitoring of the BeppoSAX
instruments and quick­look inspection of the scientific results with the
goal of detecting and locating major changes in X­Ray sources and search­
ing for X­Ray transient phenomena up to high energy events as Gamma
Ray Bursts. This is carried out by performing both Data Accumulation
and Data Presentation and Analysis by using the raw payload telemetry
data stored on orbital basis.
1. Introduction
The ground support facilities for the BeppoSAX Mission are split among di#er­
ent ground systems components:
­ the Ground Station, located in Malindi (Kenya), for the telecommands
uplinking and telemetry retrieving when the satellite is directly visible
(approximately only 10 minutes of each 96­100 minute long orbit)
­ the Operation Control Centre (BSAX­OCC), which handles spacecraft or­
bital management and payload monitoring activities
­ the Scientific Operation Centre (BSAX­SOC), where the detailed plan­
ning of the onboard scientific activities is prepared, the orbit­by­orbit raw
telemetry is archived and made immediately available to the quick­look
processing
­ the Scientific Data Centre­Mission Support Component (BSAX­SDC/MSC),
where observation requests from the astronomical community are collected
296

The Ground Support Facilities for the BeppoSAX Mission 297
and checked, long range observation plans are prepared and raw data from
the entire mission are archived and delivered to the final users as Final
Observation Tapes.
Although all facilities are split into further components (OCC, SOC, SDC/MSC
are located in Telespazio, Rome), their design and overall integration allow e#­
cient and successful management of the mission operations.
2. The BeppoSAX forward and backward Data Flow
The aforementioned system components are described following the forward and
backward data flow to/from the satellite.
The BeppoSAX Data flow starts at BSAX­SDC/MSC with the reception
and management of the Observation Proposals:
­ Proposal Reception via e­mail and ordinary mail
­ Proposal Checks for completeness, consistency and syntax
­ Proposal archiving using database technology
­ Proposal Feasibility Checks: target observability and viewing windows,
target visibility, bit­rate evaluation
Proposals approved by the Time Allocation Committee and successfully checked
contribute to the Mission Plan file preparation. The Mission Plan File is the
main input to the Proposal Scheduling steps performed at the BSAX­SOC:
­ Long­Term Planning: an optimized timeline designed to maximize satel­
lite performance taking into account the observability and operative con­
straints and the proposer's specified priorities
­ Short­Term Planning: a one­week detailed timeline containing for each re­
quested pointing the attitude sequences, the orbital links, SAGA passages
and the on­board instruments set­up
­ Urgent Observation (e.g., TOO) Management: TOO feasibility checks,
quick replanning of the current short­term schedule
The Short­Term Planning products are the main input to the Spacecraft
and Payload command sequence generation. The observation execution involves
activities which are performed at the BSAX­OCC:
­ Telecommand uplink, Telemetry acquisition
­ Spacecraft and Payload Monitoring & Control
­ Satellite ephemeris determination: prediction and reconstruction
­ Satellite attitude determination and post­facto reconstruction
During the Observation execution the raw telemetry (housekeeping and
scientific) is collected at the BSAX­SOC:
­ Orbit­by­orbit telemetry acquisition and processing
­ Telemetry Data Quality checks for completeness, integrity, consistency and
accuracy
­ Temporary Telemetry filing (data from the last 60 orbits are always on
line)
­ Quick­look Data Analysis

298 Bruca, Capalbi and Coletta
Telemetry data, grouped by Observing Period (several orbits time span)
and Auxiliary data such as On­Board­Time/Universal­Time conversion Data,
Reconstructed Attitude and Satellite ephemeris are then stored in the Bep­
poSAX Mission Raw Data Archive at the BSAX­SDC/MSC. Its organization
and management is done according to the following baseline:
­ Optical Disk media as final support for the data archiving
­ A relational database to catalogue data and address data files on media
­ Optical jukebox in order to keep more media on­line and optimize data
retrieval
The last step in the BeppoSAX data flow facilities (BSAX­SDC/MSC) is the
data delivery to the final user:
­ Observation Data (housekeeping, scientific and auxiliary) retrieving from
the BeppoSAX Mission Raw Data Archive, on the basis of the PI proposal
­ Data reformatting and storing on the requested media support (e.g., DAT,
Exabyte)
­ Product delivery to the PI
3. Quick Look Data Analysis System
The Quick Look Analysis (QLA) is mainly conceived as a quick­look system to
allow feedback to the BeppoSAX satellite as soon as possible, typically within
a few orbital periods from when the relevant events were generated on board.
The QLA is performed by a team of eight Duty Scientists working shifts to
ensure 24h data monitoring.
Input data for the QLA are payload telemetry data stored in the BSAX­
SOC Archive for a time span encompassing the last 60 orbits.
The main tasks accomplished by QLA are both health monitoring of the
BeppoSAX instruments and quick­look inspection of the scientific results with
the goal of detecting and locating major changes in X­Ray sources and searching
for X­Ray transient phenomena up to high energy events such as Gamma Ray
Bursts. These latter events, triggered by the on­board Gamma Ray Burst Mon­
itor, are analysed by the Duty Scientist Team following a well­tested procedure
and up to now several real Gamma Ray Bursts have been identified and located,
giving input to follow­up observations in di#erent energy bands. In order to
accomplish the QLA goals the system provides both Data Accumulation, Data
Presentation and Analysis tools. Implemented accumulation functions provide
scientific telemetry data retrieving, packet information extraction to perform
accumulation of X­Ray events information and integration of on­board accu­
mulated data structures. Data visualization and general analysis are based on
a Motif Graphical User Interface developed by Telespazio with the PV­WAVE
analysis environment. Based on PV­WAVE Widget Toolbox applications, the
ad­hoc software developed using PV­WAVE processing routines provides a data
analysis/manipulation system with optimum ease of use.

The Ground Support Facilities for the BeppoSAX Mission 299
Figure 1. 3D Images of four Gamma Ray Bursts discovered by Bep­
poSAX (GRB970111, GRB970228, GRB970402 and GRB970508)