NGIMS












    The Neutral Gas and Ion Mass Spectrometer (NGIMS) is a quadrupole mass spectrometer with open and closed sources. The open ion source mode is used to measure reactive neutral gas species and to sample ambient thermal and suprathermal ions while the closed source samples non-reactive neutrals. The mass range is 2 - 150 Da.

    Measurement Objectives

    NGIMS will measure the neutral composition, isotopic ratios and scale height temperature of the major gas species (He, N, O, CO, N2, NO, O2, Ar, and CO2) in the upper atmosphere. It will:
    • Determine variation of the neutral composition with altitude, local solar time, longitude and season from the homopause to the exobase where neutral gas can escape.
    • Derive stable isotope ratios and variations.
    • Provide a basis for the study of thermospheric energetics, transport, circulation, and formation of the ionosphere.
    • Reveal the effects of lower atmosphere meteorological effects, such as dust storms, on the composition of the upper atmosphere and exobase.

    Useful Mission Documents
    Mission Description and Spacecraft Description Document
    Software Interface Specification (SIS) - Description of the instrument and data structures
    Calibration Document - See SIS
    Calibration Files

    Archive Bundle Contents
    Documentation - Directory containing the document collection, which includes references to refereed journals using this instrument, and information about calibration and explanation of data structures.

    Raw Data - Directory containing the raw data files

    Calibrated Data - Directory containing the calibrated data files

    Derived Data

     Single species abundance vs. time, and vs altitude, or single species energy distribution vs. time, and vs altitude. Directory containing advanced products
    Altitude resampled abundances and energy distributions. Directory containing advanced products

    Citing Data Sets for Publications

    Benna, Mehdi; Lyness, Eric, MAVEN Neutral Gas and Ion Mass Spectrometer Data, urn:nasa:pds:maven_ngims, (2014).

    Other Useful Products for Interpreting the Data

    References - A listing of team members to facilitate literature searches

    SPICE - Archived MAVEN SPICE ancillary data providing observational geometry (positions, orientations, instrument pointing, time conversions, etc.) are available from the PDS NAIF Node.


    Caption: NGIMS will measure the composition and isotopes of thermal neutrals and ions in the Martian atmosphere (Courtesy NASA/GSFC)































    Graphical display of NGIMS-derived C02 molecule abundance (#/cm3 ) versus altitude for one orbit. The graph points were obtained from this file