INSTRUMENT_HOST_ID             = "MESS"                                    
  INSTRUMENT_ID                  = "MAG"                                     
  INSTRUMENT_NAME                = "MAGNETOMETER"                            
  INSTRUMENT_TYPE                = "MAGNETOMETER"                            
                                                                             
  INSTRUMENT_REFERENCE_INFO: PDS3_REFERENCE_KEY_ID = "ANDERSONETAL2007"      
                                                                             
    INSTRUMENT_DESCRIPTION                                                   
                                                                             
    The MErcury Surface, Space ENvironment, GEochemistry and Ranging         
    (MESSENGER) mission is designed to orbit Mercury following one Earth     
    flyby, two flybys of Venus and three of Mercury.  It launched in         
    August 2004 and will use these flybys to achieve an orbit insertion      
    around Mercury in March 2011.  Initial data collection will begin        
    during the three flybys of Mercury, and will primarily consist of        
    global mapping and measurements of the surface, atmosphere and           
    magnetosphere composition.  MESSENGER will remain in orbit for the       
    rest of the nominal mission, which is scheduled to end in March          
    2012. Once in orbit around Mercury it will begin a series of             
    observations using multiple instruments. These observations will         
    provide data to answer questions about the nature and composition of     
    the crust, tectonic history, the structure of the atmosphere and         
    magnetosphere, and the nature of the polar caps.                         
                                                                             
    The science objectives of the MESSENGER Magnetometer (MAG) are to        
    determine the structure and the origin of the intrinsic magnetic         
    field of Mercury, and to characterize the solar-wind interaction         
    with the planet.  The magnetic field data are also needed to             
    interpret data from the Energetic Particle and Plasma Spectrometer.      
    The MAG instrument is a miniature three-axis ring-core fluxgate          
    magnetometer with low-noise electronics.  It is mounted on a 3.6 m       
    boom in the anti-sunward direction.  The MAG has +/- 1530 and +/-        
    51300 nT ranges with 20-bit internal resolution and 17-bit output        
    resolution.  The MAG probe samples magnetic field values along the       
    X, Y, and Z axes at a rate of 20 samples/second.  The data passes        
    through an A/D converter where it is also filtered by the hardware.      
    The MAG software interfaces with the MAG electronics via                 
    memory-mapped I/O for data collection, range control, and                
    electronics calibration.                                                 
                                                                             
    The MAG software receives vector magnetic field samples, 20 bits per     
    X, Y, and Z axes, from the MAG electronics at 20 Hz.  After bias         
    removal, it filters and sub samples this data to generate output         
    data samples at the commanded rate: 0.01, 0.02, 0.05, 0.1, 0.2, 0.5,     
    1, 2, 5, 10 or 20 samples/second.  The MAG software consistently         
    builds science records with compressed (if commanded) MAG data           
    obtained from the above processing for transmission to the DPU via       
    CCSDS telemetry packets.                                                 
                                                                             
    Furthermore, the MAG software detects magnetic bursts during a           
    commandable time period during orbit.  The detection is done by          
    passing the field samples of a selected axis from the bias removal       
    logic through a 1 to 10 Hz pass-band filter and determining a log AC     
    value from this data.  If this value indicates that the magnetic         
    field is fluctuating above a trigger level, burst data over eight        
    consecutive minutes is collected, compressed, and sent to the DPU        
    via CCSDS telemetry packets.                                             
                                                                             
    Finally, the MAG software collects housekeeping data indicating the      
    state of the MAG instrument and software for packaging into              
    low-rate- housekeeping (LRH) telemetry packets.                          
                                                                             
    The MAG instrument is described in full detail in                        
    [ANDERSONETAL2007]."