Attitude and Drag Control: An Application to the GOCE Satellite

Embedded Model Control: Outline of the theory

“…Finer requirements as in [2,5] may ask the root of the unilateral spectral density (PSD for short) S e ( f ) of e to stay below a bound S e,max ( f ) within a frequency bandwidth (BW) 0 < f 0 ≤ f ≤ f 1 < f max = 0.5/T , which may depend on z and is bounded by the Nyquist frequency f max . In this framework, the norm in (28) becomes the error standard deviation.…”

“…can be shown to bound e, if three design matrices K , M and Q exist satisfying the following necessary and sufficient conditions (1) the closed-loop matrix A c − B c K is asymptotically stable, (2) there exists at least one solution to the matrix equation…”

“…Since then, EMC has been fully developed and applied to different applications, the most recent being [2][3][4][5][6]19]. The present theory outline revises, simplifies [1] and prepares for a paper showing a standard application: web winding [17].…”

Local orbital frame predictor for LEO drag-free satellite

“…Study and simulation results are justified by the drag-free and attitude control of the GOCE satellite (gravity field and steady-state ocean circulation explorer), the LORF being the instantaneous reference for satellite attitude and scientific data [3,5]. The GOCE satellite, launched in March 2009, will fly in a near-circular, sun-synchronous orbit (96.5 • inclination) at a mean geodetic height h250 km, with a mean orbital rate O 1.17 mrad/s.…”

Noise reduction through joint processing of gravity and gravity gradient data

“…When using this system, common-mode nongravitational linear accelerations, sensed identically by two accelerometers, cancel out during data acquisition. Devices and special processing techniques reduce the noise associated with nonlinear accelerations of the craft from sources such as ship rolling or aircraft bumping ͑Canuto et al, 2003;Dransfield and Lee, 2004͒. Measuring gravity gradients retrieves features at a smaller scale than those characterized with similarly retrieved gravity measurements ͑European Space Agency, 1999; Mumaw, 2004͒. Thus, removing noise in gradient data without filtering out high-frequency information is a challenge.…”