Simulation of an NGS Speckle Observation with a 30 meter Telescope
Here is a movie showing simulations of the effects of focal
anisoplanatism from a Sodium LGS for a 10 meter telescope.
focal anisoplanatism movie
On the left side of the movie is the wavefront phase in the pupil
plane of a 10 meter aperture formed by subtracting the LGS wavefront
from an NGS. The apparent hole in the middle of the pupil plane phase
is a result of the fact that the on-axis LGS correction is perfect,
while the correction gets worse as one moves off axis. On the right
side of the movie is the resulting PSF. The LGS is modelled as a
point source positioned at 90 km.
The parameters for this simulation were:
10 meter aperture
LGS height of 90 km
1 micron radiation
r0 of .3 meters at 1 micron
2 cm pixel scale in the wavefront
2 cm pixel scale in the turbulence layer
time step of duration 10 milliseconds
5 seconds of simulation time
This simulation was generated using the program focal_anisoplanatism_simulation, which is
provided as part of the arroyo distribution.