WLDCL in European Space Agency's research project "Multi-Magnetometer Methods for Magnetic Dipole Modelling"
In various exploration missions, magnetometer-carrying spacecrafts aim to reveal the structural composition of planets and to study the complex interactions between the solar wind and the planetary environments. Magnetic field levels are usually extremely low making the need for “magnetically clean” spacecraft. Magnetic cleanliness is based on identification of subsystems and components with potential contribution to magnetic field emissions, equipment (unit) level measurements at Mobile Coil Facilities (MCF), for characterization and acceptance and system level either by simulation or in large magnetic facilities for final testing. These facilities use a small number of magnetometers and employ rotational measurements to obtain a magnetic signature around an Equipment Under Test (EUT). Disturbances of the ambient field during the test can require several repetitions. In the frame of this activity the rotation shall be completely replaced by an increased number of fixed magnetometers. A typical Mobile Coil Facility is shown in Figure 1. The aim of this project is to increase reproducibility of test results by a reduction of measurement sensitivity to environment variations occurring during the test. The activity shall strive in parallel also to reduce considerably required test time and necessary operator expertise
Scope - Consortium
The first principal activity of this work is to study different possible multi-magnetometer test setups with the following targets: To obtain a snapshot of the magnetic field and its gradient for a unit while keeping measurement time below 1 second. To identify the optimum number and position of magnetometers and the parameters affecting the reproducibility of test results. To reveal possible additional capabilities the use of gradiometer configurations was also exploited. The pros and cons of possible resultant setups have been examined in a trade-study that optimizes instrumentation, hardware (mechanical and electronics) and software implementation while meeting project requirements.
The second principal activity is the design, implementation and operational/performance verification of the new, multi-magnetometer, facility. The desired solution has two major targets:
- To reduce total measurement time so as to avoid influence of ambient field variations compared to the current turntable mechanism. In general, the measurement sequence of: Ambient B-field measurement (AMBbefore) – EUT snapshot field measurement (EUT) - Ambient B-field measurement (AMBafter) should be performed as fast as possible to reduce effects of ambient field variation to the snap-shot EUT magnetic field measurement result.
- To make the new multi-magnetometer test facility operate with desired accuracy, resulting in better quality measurements and helping the modeling algorithms to produce better results. The new system shall be verified for its performance and accuracy against given requirements.
The implementation of the proposal is based on a consortium of two contractors. One new and upcoming company interested in consulting and development of real-time embedded systems and software, and a university laboratory interested in high-technology research, form a complete team that includes all the desired resources. More specifically the consortium consists of the following contractors:
NIKOLAOS & MARINOS LIVANOS OE – EMTECH; a Greek company involved in embedded systems and software design and development, manufacturing products for the domains of Energy Systems and Automations, Space and Ground Segment Software Applications, and Medical Devices.
Wireless and Long Distance Communications Laboratory (WLDCL) of the National Technical University of Athens (NTUA), with domains of specialty the theoretical and experimental research on telecommunication topics, emphasizing on subjects such as Electromagnetic Compatibility, Antennas, Radiation Effects, Wireless Links and Propagation and Biotechnological issues.