| General characteristics | ||
| Frequency range: 150 - 450 MHz | ||
| Baselines from 50 to 3200m (25 to 4,800 l) | ||
| 576 baselines (with some redundancies) | ||
| Spatial resolution: ~4 to 0.3 arcmin (depending on frequency, declination, snapshot/synthesis) | ||
| Field of view: from 3 to 0.5 degrees | ||
| Stokes I and V | ||
| Time resolution: 5 ms* number of frequencies | ||
| General characteristics (cont.) | ||
| Bandwidth: 700 kHz | ||
| Dynamic: 45 db (power in that bandwidth) | ||
| Separate flux receivers set attenuators (time constant: 5 ms) | ||
| Multifrequency done by high speed (5ms) frequençy switching between 5 to 10 frequencies | ||
| Further integration gives standard mode: 8 Im./sec for 5 almost simultaneous frequencies. | ||
Nançay Radioheliograph: 5m antennas (north-south array)
Nançay Radioheliograph: East - west array flat antennas
| Low gain antennas: (~wide band dipoles) | |
| Severe sensitivity limitation at high frequency | |
| One linear polarization |
| Data processing | ||
| Integrated datas (images, fits,mpeg) available on line after the observation | ||
| 10 sec integrated datas available on line 2 weeks after | ||
| High resolution data on request | ||
| Software | ||
| NRH package included in Solarsoft: image processing, parameters as function of time, CLEAN… | ||
| Mpeg daily files (2000 june ,14) |
| Upgrade ( spring 2002 ?) | |||
| 4 antennas (low gain log-periodic), adding 68 visibilities in the central part of the u-v plane | |||
| Larger field of view | |||
| Aliasing suppressed in most cases | |||
| Better flux measurement for extended objects | |||