WP 100: Analysis of Freja charging events (IRF-U)

WP 110: Event identification and case studies

A detailed analysis of at least 10 Freja charging events from the statistical study (WP 130), which illustrate the different (if several) charging processes detected in the Freja data selected over the whole altitude range covered by the Freja spacecraft. This analysis will include the precise electron and ion energy distributions, lightning characteristics, geomagnetic location and activity conditions, as well as the cold plasma density and temperature characteristics. The aim of the study will be to identify the precise mechanism behind the charging events that operate at Freja altitudes. The detailed study of these events will be compared to similar studies carried out with the DMSP and ARCAD spacecraft, and the electrostatic environment will be investigated for the Freja case with this comparison in mind.

WP 120: Comparison with S/C charging codes

- Selection and preparation of a few (2-5) detailed analysed spacecraft charging events to be used for input to two spacecraft charging software, NASCAP and POLAR, provided by ESTEC
- Prepare a list of already available information of the materials used on the Freja spacecraft surface from the Swedish Space Corporation
- Comparison of the NASCAP/POLAR program results, based on the input above, with the actual observed Freja spacecraft charging events

WP 130: Statistical occurrence of charging events

A statistical study based on a substantial amount of the Freja spacecraft data in order to establish the occurrence and intensity characteristics of spacecraft charging events along the Freja orbits, using the full altitude extent (600-1800 km) of the Freja measurements. The statistics shall be complemented with information on the environmental characteristics during charging events. In particular, the cold plasma density, cold plasma temperatures, energetic electron and ion energy distributions, lightning conditions, geomagnetic location (MLT, CGLAT, UT), geomagnetic activity (Ap, Kp, solar wind Bz components), and possible variations during the Freja operation time (1992-1995) will be investigated and documented.

WP 200: Spacecraft anomaly forecast system (IRF-K)

WP 210: Simulation of S/C anomalies with local measurements

Satellite anomaly data and local measurements will be used for:
- analysis of high and medium energy electron influence on space systems
- analysis of anomaly occurrence frequencies and locations
- analysis of the environmental data set
- development of a neural network for anomaly prediction
- tests of the prediction system at ESTEC

WP 220: Simulation of S/C anomalies with non-local measurements

This work package includes:
- analysis of possibilities to use non-local data for anomaly prediction
- review of existing routine measurements of environmental data
- training of a neural network to predict the risk of spacecraft anomaly based on non-local data
- investigation of the possibility to define an anomaly risk index

WP 230: Simulation of S/C anomalies with heterogeneous data

The analysis shall result in:
- recommendations for how a combination of local and non-local measurements can forecast the risk of anomalies
- a review of literature on spacecraft anomalies
- possibilities to improve on-board instrumentation for space environment monitoring

WP 300: Global space plasma modelling programme (FMI/GEO)

WP 310: State of the art of space weather modelling

- analysis of the impact of solar-terrestrial relations on space systems
- review of current modelling capabilities for the relevant space plasma and energetic electron environments and associated disturbances
- analysis of the end-user requirements
- analysis of the physics requirements for modelling improvements
- evaluation of physics-based limits of predictability of the space plasma environment
- analysis of practical aspects for improvement of space weather modelling
- assessment of specific European capabilities for space weather activieties
- recommendations for rationalized development of space weather activity in Europe
- suggestions for space weather studies making use of Cluster and SOHO data

WP 320: Requirements for modelling tools

The analysis shall result in requirements for tools developed for
- an operative system for prediction of hazardous conditions, and
- post-event analysis of conditions during observed spacecraft anomaly events,
both giving relevant physical parameters at a given point in the (inner) magnetosphere, using available ground-based, magnetospheric, solar wind and/or solar data

WP 330: Development of space weather information server

Contents of the WWW server
- description of the existing European space weather resources
- links to other space weather servers
- access to data bases necessary for estimation of anomaly risks
- technical notes and other documentation of this study

WP 400: Management and project control (FMI/GEO)

WP 410: Contractual management

WP 420: Project control

- quality assurance of S/W products and documents
- quality assurance of charging and anomaly studies

17.10. 2003 - Ari Viljanen (email: firstname.lastname@fmi.fi)