Accelerometers
type: Concept

EGG
change note: 2019-07-16 06:26:58.0 [mmorahan] Move Concepts delete broader relation (null); add broader relation (EGG [11c1598b-d484-4c26-83ae-bc12af957b84,346357] - Accelerometers [11208f10-6879-48ca-919c-88558391403b,346347]);
change note: 2019-07-16 06:25:48.0 [mmorahan] Cut Concepts delete broader relation (null); add broader relation (EGG [11c1598b-d484-4c26-83ae-bc12af957b84,346357] - Trash Can/Instruments [4b2630a8-2630-42f1-852f-772e9a62efe7,354157]);
in scheme: instruments
definition: [Source: ESA's Gravity Mission GOCE Brochure, http://esamultimedia.esa.int/docs/BR209web.pdf ] The principle of operation of the gradiometer relies on measuring the forces that maintain a ‘proof mass’ at the centre of a specially engineered ‘cage’. Servo-controlled electrostatic suspension provides control of the ‘proof mass’ in terms of linear and rotational motion. Three pairs of identical accelerometers, which form three ‘gradiometer arms’, are mounted on the ultra-stable structure. The difference between accelerations measured by each of two accelerometers (which are about 50 cm apart), in the direction joining them, is the basic gradiometric datum. The average of the two accelerations is proportional to the externally induced drag acceleration (common mode measurement). The three arms are mounted orthogonal to one another: one aligned with the satellite’s trajectory, one perpendicular to the trajectory, and one pointing approximately towards the centre of the Earth. By combining the differential accelerations, it is possible to derive the gravity gradient components as well as the perturbing angular accelerations. Group: Instrument_Details Entry_ID: EGG Group: Instrument_Identification Instrument_Category: In Situ/Laboratory Instruments Instrument_Class: Magnetic/Motion Sensors Instrument_Type: Accelerometers Short_Name: EGG Long_Name: Electrostatic Gravity Gradiometer End_Group Group: Instrument_Associated_Sensors Short_Name: ACCELEROMETERS End_Group Group: Associated_Platforms Short_Name: GOCE End_Group Online_Resource: http://esamultimedia.esa.int/docs/BR209web.pdf Online_Resource: http://www.esa.int/esaLP/ESAHTK1VMOC_LPgoce_0.html Creation_Date: 2009-05-15 Group: Instrument_Logistics Instrument_Start_Date: 2009-03-20 Instrument_Owner: ESA End_Group End_Group
type: Concept