Showing papers by "European Space Operations Centre published in 2004"
TL;DR: The METEORO and Space Debris Terrestrial Reference Model (MASTER-2001) as mentioned in this paper is based on quasi-deterministic principles, using comprehensive orbit propagation theories and volume discretisation techniques, to derive spatial density and velocity distributions in a three-dimensional control volume ranging from LEO to GEO altitudes.
28 citations
TL;DR: In this paper, the sensitivity of the DELTA model to changes in key model parameters and assumptions is examined, such as the variation in future traffic rates, including the deployment of satellite constellations, and variation in the break-up model and criteria used to simulate future explosion and collision events.
26 citations
TL;DR: In this paper, a comparison of widely distributed debris flux models which were recently updated, namely ESA's MASTER model, NASA's ORDEM 2000 and the Russian SPDA 2000 model is performed by applying the models to a large number of target orbits specified by a grid in terms of impactor size (6 gridpoints), target orbit perigee altitude (16 grid points), and target orbit inclination (15 gridpoints).
23 citations
TL;DR: In this article, the libration amplitude of Mercury can be determined by comparing pairs of images of the same landmarks taken by an orbiter at different positions of the planet at different angles.
22 citations
TL;DR: In this paper, the authors developed a technique to estimate the absolute strength and direction of the geomagnetic field from a marine vessel by turning the ship through 360° at a place where the strength of the field is known.
Abstract: We have developed a technique to estimate the absolute strength and direction of the geomagnetic field from a marine vessel. This technique will be of value in the study of marine magnetic anomalies, directional drilling or geomagnetic field modelling. One of the main difficulties in this operation is to correct the data for the magnetic field generated by the vessel itself. Assuming the vessel susceptibility is isotropic, we show that by turning the ship through 360° at a place where the strength of the field is known we can estimate the local direction of the magnetic field. Once this is known, the vessel's field at any attitude can be robustly estimated and the measurements of the full magnetic field vector made in a normal surveying mode can be corrected. The ambient magnetic field estimates at the turn locations have proved to be very accurate. In normal surveying mode, these estimates are not as good since they are directly dependent on the accuracy of the vessel attitude measurements. However, when the technique is applied on real data, the total intensity field estimates have a very low level of noise showing that the vessel signal has been well accounted for.
15 citations
TL;DR: In this paper, the authors highlight the challenging aspects of the Cluster II mission from both the operations and flight dynamics point of view, and discuss the manoeuvre strategy required to place the two pairs in the operational orbit and to achieve the initial constellation.
15 citations
TL;DR: Design aspects of the MPS of the ENVISAT Flight Operations Segment are presented, designed to allow direct involvement in the planning process of authorized user groups and external instrument operators, up to the provision of uplinkable instrument parameters.
3 citations