Last changed in November 2001 by S.-R. Zhang

# Millstone Hill Regional Ionosphere Model

This model utilizes the radar observations of basic ionospheric
parameters (electron density and temperature and ion
temperature). Measurements are binned in 1 hour local time, 1 degree
geographic latitude from 32-55 degrees geodetic, and 50 km altitude
bins from 200-600 km. Inputs to the model are the F10.7 index (which
provides a measure of solar irradiance) and the Ap index (which
provides a measure of geomagnetic activity).
The entire Millstone Hill database is binned in 1hr local time by 50
km altitude by 1 degree latitude bins. In each bin, the dependencies
on solar and magnetic activity are determined through a least squares
fit to the following equation:

Ne = A + B * F10.7 + C * Ap + D * Ap*F10.7

Where Ne is the electron density, A-D are the fit coefficients, F10.7
is the previous day's F10.7 index, and Ap is the Ap index for the
previous 3 hours. This functional form is also used to fit the
electron and ion temeperature data as well.
### Animated GIFs