Instrument Information |
|
IDENTIFIER | urn:nasa:pds:context:instrument:imf.sakig::1.0 |
NAME |
INTERPLANETARY MAGNETIC FIELD EXPERIMENT |
TYPE |
MAGNETOMETER |
DESCRIPTION |
Instrument Overview =================== The Interplanetary Magnetic-Field Experiment is designed to study macroscopic and microscopic structures in the helio-magnetosphere and in the cometary magnetosphere, as well as large-amplitude low-frequency hydromagnetic waves in the solar wind. The data gathered will be compared with the configuration, brightness and variations of Halley's corona, which will be imaged by the UV camera on Planet-A. The IMF is to be measured by a triaxial, ring-core, fluxgate magnetometer sensor mounted on a 2 m-long boom. This boom was extended soon after injection of the spacecraft into orbit. From a block diagram of the IMF instrument, the dynamic ranges of which are +/- 64 nT and +/- 128 nT. The table below summarizes the instrument's sensitivity, resolution, bit rate, and sampling rate. The dynamic range and conversion output will be selected by ground command. During the initial period of the mission, when the telemetry signals are strong enough, the high-bit-rate data will be used for the study of the ULF hydromagnetic waves. The low-bit-rate data will be used while the spacecraft is closer to Comet Halley to study the macroscopic structure of the helio-magnetosphere and the cometary magnetosphere. _______________________________________________________________________ Table. Characteristics of the Interplanetary Magnetic-Field Instrument Sensitivity Sampling rate (s) Dynamic Resolution Telemetry bit Format-3 range (nT) Output (bit) (nT/LSB) rate (bit/s) Format-1 & 4 ----------------------------------------------------------------------- h.b.r. 1/8 1/16 +/- 64 12 (high gain) 0.03125 l.b.r. 4 2 (Narrow) 8 (low gain) 0.5 h.b.r. 1/16 1/32 l.b.r. 2 1 ----------------------------------------------------------------------- h.b.r. 1/8 1/16 +/- 128 12 (high gain) 0.0625 l.b.r. 4 2 (wide) 8 (low gain) 1.0 h.b.r. 1/16 1/32 l.b.r. 2 1 ----------------------------------------------------------------------- h.b.r. = high bit rate (2048 bit/s) l.b.r. = low bit rate (64 bit/s) |
MODEL IDENTIFIER | |
NAIF INSTRUMENT IDENTIFIER |
not applicable |
SERIAL NUMBER |
not applicable |
REFERENCES |
Reinhard, R and B. Battrick (eds), 'Space Missions to Halley's Comet', European
Space Agency ESA SP-1066, ESA Pub Div, Moordwijk, Netherlands, 1986. 'Encounters with Comet Halley, The first results', Nature, Volume 321, No. 6067, 15 May 1986. |