ECHO First Images

Welcome to the ECHO first images home page for December 15, 1999. The ECHO (Experiment for Coordinated Helioseismic Observations) is a network of two instruments which observe solar oscillations as seen in the radial velocity of the solar surface. The ECHO is the next generation of the LOWL instrument, which has been operated at the Mauna Loa Solar Observatory of the National Center for Atmospheric Research for the past 6 years. The first of the new ECHO instruments became operational on Dec 15, 1999 at the Observatorio del Teide, located at Izana, Tenerife, Spain. The LOWL instrument will soon be upgraded and become the second instrument in the ECHO network.

This page contains the first Velocity images of the sun obtained by the ECHO instrument at Izana. You will also find Difference images (the change in Velocity images from one minute to the next) and animations of these.

ECHO Velocity Images
These Velocity images pictorially show the radial (line of sight) velocity of the sun across its entire surface. The gradient from left to right is due to the sun's rotation, which is towards the observer at the left limb and away from the observer at the right limb. The mottled surface is due to solar flow patterns such as granulation and supergranulation, as well as the oscillations.

The time stamp in the lower left corner is DDThh:mm in UTC.

	ECHO Difference Images These images are obtained by taking the difference between two successive Velocity images. This removes the signal from the solar rotation and the long lived flow patterns and allows easier visualization of the oscillatory signal. The darkness/brightness of each pixel represents how fast that part of the sun is moving towards/away the observer.