next up previous contents
Next: Introduction Up: Contents Previous: Contents

List of main symbols

A, B   		 parameterisation coefficients


structure coefficient of the index of refraction

temperature structure coefficient

adimensional pressure coefficient

D (mirror) diameter

temperature structure function

Fr Froude number

f focal distance

e turbulent kinetic energy

g gravity acceleration

h heat transfer rate

central intensity ratio

turbulence intensity

eddy diffusivity for momentum

eddy diffusivity for temperature

L Monin-Obukhov length

length scale of turbulence along mean flow direction

l inner scale of turbulence

N index of refraction

n frequency

P pressure

Q dissipated power

q heat flux normalised by

surface heat flux

Ra Raleigh number

Re Reynolds number

Ri Richardson number

Fried parameter for seeing

S Strehl ratio

T (mean) temperature

t thickness

U wind or air flow speed

friction velocity

v water vapour pressure

z height

telescope azimuth angle


zenithal angle of the direction of observation

dissipation rate of kinetic energy

dissipation rate of temperature

thermal diffusivity of air

wave number

light wavelength

similarity scale for quantity i

kinematic viscosity

air density

root mean square of quantity i

wavefront rms error

long exposure angular image size on the sky (generally FWHM)

image size due to natural seeing

rms of high frequency guiding errors


AAT 		 Anglo-Australian Telescope

CFHT Canadian French Hawaii Telescope

CIR Central Intensity Ratio, a measure of the optical quality of a telescope

DIMM Differential Image Motion Monitor, a special 35-cm telescope for measuring seeing

ESO European Southern Observatory

FWHM Full Width Half Maximum of the point spread function

MMT Multi-Mirror Telescope

M1 Primary mirror of a telescope

M2 Secondary (upper) mirror of a telescope

NTT New Technology Telescope, the newest 3.5-m telescope located at ESO's

La Silla observatory

PSD Position sensing detector

PSF Point Spread Function (light intensity profile)

VLT Very Large Telescope, a 48-m telescope project presently under construction

next up previous contents
Next: Introduction Up: Contents Previous: Contents

Lorenzo Zago,, Sun Feb 26 22:57:31 GMT+0100 1995