Instructions for using the Friendly Virtual Radio Interferometer.

1) Select an array configuration by clicking in the right-hand table. The layout of the antennas will be shown in the scatter plot on the right.

2) Use the slider to set the hour angle range. This range can be different for each array configuration chosen.

3) Choose a sampling cadence for the chosen array configuration. This is the interval between model visabilities.

4) Click the ‘Add’ button to add the selected array configuration, hour-angle range and sampling cadence to the observation table.

5) Repeat steps (1) to (4) to accumulate further observations.

6) Click on the folder icon to browse for a model image. Valid image formats include PNG, JPEG and GIF. If the python ‘cv2’ module is available a camera button will be available. Clicking on this icon will capture a photo with the the webcam and use this as a model image.

7) Edit the Pixel Scale value to set the size of your model image (assumes square pixels).

8) Set the Source Declination and Observing Frequency to suitable values.

9) Run the observation by clicking on the ‘Do Observation’ button.

10) Click on the ‘Show Plot Window” button to view the results (uv-Coverage, Model FFT, gridded FFT, Synthesised Beam and Observed Image) in the display window.

Note that uv-coverage and model FFT can be calculated as soon as an array
configuration and model image are loaded, respectively.