Global Reference Atmospheric Model (GRAM) Suite

About this technology

Overview

The Global Reference Atmospheric Model (GRAM) Suite is an engineering-oriented atmospheric model that estimates mean values and statistical variations of atmospheric properties for planetary destinations. GRAM outputs include atmospheric density, temperature, pressure, winds, and chemical composition along a user-defined path. The GRAMs have been rearchitected from Fortran to a common object-oriented C++ framework. This new architecture creates a common GRAM library of data models and utilities. The GRAM ephemeris has been upgraded to the NASA Navigation and Ancillary Information Facility (NAIF) Spacecraft Planet Instrument C-matrix Events (SPICE) toolkit. The GRAM Suite also contains improved methodology that computes the ratio of specific heats in run-time for the current constituent combination, resulting in more accurate speed of sound calculations. The GRAM Suite consists of Earth-GRAM, Mars-GRAM, Venus-GRAM, Neptune-GRAM, Titan-GRAM, Uranus-GRAM and Jupiter-GRAM.