Siberian Radioheliograph: first results

The 1024 channel digital correlator receiver of the Gauribidanur radioheliograph

A low frequency (40–150 MHz) radioheliograph for observations of the solar corona is in operation for the last few years at the Gauribidanur radio observatory, about 100 km north of Bangalore. The array has 32 antenna groups and a 1-bit digital correlator system consisting of 1024 channels is used as the back-end receiver. This paper describes the latter and results of the associated system tests.

Perceptual Quality Improvement for Synthesis Imaging of Chinese Spectral Radioheliograph

Chinese Spectral Radioheliography can generate the images of the Sun with good spatial resolutions. It employs the Aperture Synthesis principle to image the Sun with plentiful solar radio activities. However, due to the limitation of the hardware, specifically the limited number of antennas, the recorded signal is extremely sparse in practice, which results in unsatisfied solar radio image qual...

Siberian Pine Decline and Mortality in Southern Siberian

Best-First Minimax Search: First Results

We present a very simple selective minimax search algorithm for two-player gaines. It ahvays expands next the frontier node at the end of the principal variation, or current best line of play, which is the node that determines the minimax value of the root. The algorithm requires no information other than a static evaluation function, and its time overhead per node is similar to that of alpha-b...

RHESSI: First Results

The RHESSI observations consist of imaging spectroscopy in the γ-ray, hard X-ray, and “firm X-ray” (3-20 keV) bands. These data are now the most extensive and capable solar high-energy observations at high spectral and spatial resolution. The low-energy hard X-ray spectrum bridges the thermal and non-thermal ranges of solar electron distributions in flares systematically for the first time. In ...