MAGNETOMETERS
type: Concept

VFM
type: Concept
definition: VFM is the prime instrument of the Swarm mission developed at DTU Space. The objective is to measure the magnetic field vector, on the boom, together with the star tracker for precise attitude measurement. The boom mounted Swarm vector magnetometer instrument consist of a triple star sensor block and a CSC (Compact Spherical Coil) vector magnetometer sensor, mounted on a stable optical bench (Figure 8). Each satellite contains the optical bench with one CSC and three CHU (Camera Head Unit). The three star sensor units are arranged with the boresights 90º from each other so as to ensure that only one CHU may be affected by Sun or Moon intrusion at any given time. Hereby an attitude solution accurate in all three degrees of freedom can be delivered to the CSC throughout the entire mission. The CSC sensor and the triple star sensor block are mounted on either end of a highly stable mechanical structure. The CSC vector sensor is supported by a zero CTE (Coefficient of Thermal Expansion) CFRP (Carbon Fiber Reinforced Polymer) adapter that on the one end matches the zero CTE CFRP tube, used to displace the CSC sensor from the star sensor heads (CHU), and on the other end matches the 32 ppm CTE CSC sensor, by means of a finger section. The rotational symmetry of this design ensures an excellent angular stability. The other end of the CFRP tube is attached to a CSiC bracket holding the three CHUs. The CSiC exhibit a heat distribution capacity second to none, minimizing thermal biases of this section, from the inevitable thermal gradient induced when the sun happens to illuminate any of the three CHUs. Because the CSiC is weakly magnetic, this material can only be used at distances larger than 20 cm from the CSC sensor. Each CHU is fitted with a straylight suppression system that is thermally decoupled from the optical bench. This separation minimizes thermal excursions from the time varying sun impingement over an orbit to less than a few degrees C. The straylight suppressi…
change note: 2018-07-11 11:10:31.0 [mmorahan] insert AltLabel (id: null category: primary text: Vector Field Magnetometer language code: en); insert Definition (id: null text: VFM is the prime instrument of the Swarm mission developed at DTU Space. The objective is to measure the magnetic field vector, on the boom, together with the star tracker for precise attitude measurement. The boom mounted Swarm vector magnetometer instrument consist of a triple star sensor block and a CSC (Compact Spherical Coil) vector magnetometer sensor, mounted on a stable optical bench (Figure 8). Each satellite contains the optical bench with one CSC and three CHU (Camera Head Unit). The three star sensor units are arranged with the boresights 90º from each other so as to ensure that only one CHU may be affected by Sun or Moon intrusion at any given time. Hereby an attitude solution accurate in all three degrees of freedom can be delivered to the CSC throughout the entire mission. The CSC sensor and the triple star sensor block are mounted on either end of a highly stable mechanical structure. The CSC vector sensor is supported by a zero CTE (Coefficient of Thermal Expansion) CFRP (Carbon Fiber Reinforced Polymer) adapter that on the one end matches the zero CTE CFRP tube, used to displace the CSC sensor from the star sensor heads (CHU), and on the other end matches the 32 ppm CTE CSC sensor, by means of a finger section. The rotational symmetry of this design ensures an excellent angular stability. The other end of the CFRP tube is attached to a CSiC bracket holding the three CHUs. The CSiC exhibit a heat distribution capacity second to none, minimizing thermal biases of this section, from the inevitable thermal gradient induced when the sun happens to illuminate any of the three CHUs. Because the CSiC is weakly magnetic, this material can only be used at distances larger than 20 cm from the CSC sensor. Each CHU is fitted with a straylight suppression system that is thermally decoupled from the opt…
change note: 2019-02-22 17:27:59.0 [mmorahan] insert WeightedRelation (id: null related concept uuid: 054787a6-0c47-43af-a4ee-05c572dd1705 relationship type: null relationship value: null generated by: null); insert WeightedRelation (id: null related concept uuid: ab7f9a64-ca5d-4795-94ff-fd5367d39f9f relationship type: null relationship value: null generated by: null); insert WeightedRelation (id: null related concept uuid: 769a52d4-7db1-4b8e-8d39-6fee4e74d34f relationship type: null relationship value: null generated by: null);
change note: 2018-07-11 11:07:24.0 [mmorahan] Insert Concept add broader relation (VFM [03d748ff-7398-4ea8-87e7-38d0ef3e6167,367835] - MAGNETOMETERS [deac2632-5c17-4d15-ae92-c61ebc5a405a,348905]);
in scheme: instruments