SEE PRODUCTS / SEE Related Model & DB -
Ionosphere and
Thermosphere (Solar and Thermal Environment)
EARTH GLOBAL REFERENCE
ATMOSPHERIC MODEL (Earth-GRAM 2007)
What's New:
Earth-GRAM 2007 Version 1.1 Upgrade
Some minor changes to the
original Earth-GRAM2007 have been made that may affect
particular applications. They include:
* Changes to the
initial radll subroutine to calculate great-circle lat-lon
distance with a more precise routine (based on cross product
and sine of angle,
rather than dot product and cosine of angle).
* Adjustments of the
temperature perturbation magnitude at high altitudes (> 90
km).
* Corrects the name of
subroutine GeodettoGeocent_E07.
* A code patch to
prevent standard deviations from updating if iupdate is off
(<0). This has no effect on stand-alone Earth_GRAM, and
applies only for gramtraj implementations in
trajectory codes that use the iupdate feature to update mean
values, without updating perturbations.
* Adds a test in the
radll function to make it more robust.
* Prevents a terminal
error condition from occurring if points below sea level are
reached and the max number of points has not been reached.
Description:
Global model, using empirical database, giving density,
temperature, pressure, winds, and selected atmospheric
constituent concentrations, from the surface of the Earth to
orbital altitudes, as a function of geographic position and
time of year. Local perturbations about mean conditions are
also included. Model is also suitable for use as a subroutine
in a trajectory code or orbit propagator program or other
programs used for simulations of in-flight or on-orbit
atmospheric variability in density, temperature, or winds.
New Features of GRAM 2007 -
Additional Information:
Language: FORTRAN 77
Operating System: PC/DOS, Unix
Hardware Requirements: Runs on
PC (or compatible) and on most Unix hardware, must have CD-
ROM for Global Upper Air Climatic Atlas (GUACA) data set. Need
at least 20 MEG of storage space.
Availability:
- Maintenance/ Upgrades: On an
as needed basis
- Source Code: Source code is
available
-
Cost:
Program: No cost to qualified, NASA approved users
- Distribution: Available upon request at
http://see.msfc.nasa.gov/ModelDB/ModelDB.htm
- Manuals: Yes
- Training: No
Input Description: Geographic
position, time, GUACA data (for heights below 27 km), solar
and geo-magnetic data (for heights above 90 km)Output Format: Density,
temperature, pressure, winds, and selected atmospheric
constituent concentrations, from the surface of the Earth to
orbital altitudes.
Verification/ Validation: Model is
based on empirical data and validated against other empirical
data and previous models.
NOTE: GRAM 2007 includes the option to
use Global Upper Air Climatic Atlas (GUACA) or Global
Gridded Upper Air Statistics (GGUAS) CD-ROM data sets for
0-27 km altitudes. Please click
here to obtain ordering
information for the GUACA and GGUAS data sets. If you
have any additional questions, please don't hesitate to
contact us.
Point of
Contact:
C. G. (Jere) Justus
EV13/UNITeS
NASA Marshall Space Flight Center
MSFC, AL 35812
Phone: (256)-544-3260
E-mail: Carl.G.Justus@nasa.govFred Leslie
EV13/NASA
NASA Marshall Space Flight Center
MSFC, AL 35812
Phone: (256) 544-1633
E-mail: Fred.W.Leslie@nasa.gov
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