The Ideal Radio Telescop applet is a simulation of such a perfect but non-existing instrument. With it we can inspect the radio sky at any frequency (between about 1 and 30 GHz) as seen with a parabolic dish of any diameter and with a receiving system of any system temperature. Continuum emission from the quiet Sun, the Moon, an Earth-temperature flux calibration source, and a number of galaxies and nebulae as well as the thermal emission from the Earth atmosphere are simulated. For a number of real telescopes realistic noise can be added to the data.
The applet is organized in several pages which are accessed by the top buttons. They are

• Telescope allows to define the parameters of the instrument
• Operate is the main page to orient the telescope and to take measurements
• Skyview presents a view of the sky, with the actual positions of the Sun, the Moon, the Galactic Plane (Milky Way) (blue curve with filled dot for the Galactic Centre and open circles for (90, 180, and 270° longitude) and the Clarke Belt of geostationary satellites (green curve)
• (Spectrum not yet implemented)
• (Scan permits to take measurements while scanning an arc in the sky - not yet implemented)
• (Map would scan a rectangular region in the sky to make a radio image - not yet implemented)
• Output is a feature of the Trainer applet only. Here we can grab the recorded measurement data, which is normally written into a file.
• (Batch is a feature to be done, to control the instrument by a sequence of commands ...)

• Telescope page shows the parameters of the telescope: one can change the geographical position of the observer, the sky position of the flux calibrator, and the format of the output data. There is a Choice between a number of real telescopes, which set the frequency, diameter and system temperature. When modifying the frequency, diameter, HPBW or antenna gain, hit the enter key - the green field indicates from which datum the other two are computed. NOTE: click the accept settings button to make your parameters valid for the telescope

• Operate page:
• The current position is indicated in the two fields for Azimuth and Elevation in the centre. Below are the corresponding fields to enter a desired position. The button Goto will start the movement.
• The button "Az/EL" can be used to switch the display between "Az/El", "RA/Dec", and galactic coordinates "Glon/Glat"
• several Buttons permit to orient the telescope: goto Calibrator goto Astra 1 will start the repositioning. Sun now and Moon now will only display the positions of the bodies
• There is also a Choice to select a celestial object: this will display the present or the future position, with the number of seconds specified.
• A position can also be entered in the Az/El fields. Hitting the 'Enter' key will start the movement.
• Likewise, horizontal and vertical offsets can be applied to the presently used position. Hit the 'Enter' key to effect repositioning. Note that the horizontal offset is in proper degrees, and that the azimuth offset is hoffset*cos(elevation)!
• Start, Stop, Resume control the measurements and their recording.
• As long as the measurements take place, we cannot change the vertical scale of the chart display by using the scroll bars on its left. Otherwise this could cause problems in the refreshing of the plot. To avoid these troubles, we simply Stop the measurements briefly, adjust the display to our wishes, and then Resume the measurements.
• The main chart gives a tracing of the signal strength as a function of time. To its right a bargraph gives an analog display of the current measurement, whose value is also displayed numerically.

• SkyView page shows the sky above the telescope: there are a few features (buildings, trees) which limit the view of the horizon. The light blue area is the region into which the telescope is permitted to be operated. Sun, Moon, and the flux calibrator source are marked by symbols. The present position is indicated by a small cross.
• The green curve marks the Clarke Belt of geostationary satellites: as these constitute strong emission in the 10 GHz band, it is not advisable to try to observe the Moon when it is close to the Belt.
• The blue curve indicates the middle line through the band of the Milky Way, the Galactic Plane. Note that the line and continuum emission from this region is NOT (yet? ;-) simulated.
• The yellow fields on the left are buttons to change the time of the display, and of the operation of the telescope. Thus it is possible to simulate observations at other times.
• Clicking on the display will cause this position's coordinates to be displayed on the right hand side. If this happens to be on or very close to a source (red dots) the name of the source is displayed as well. Clicking on the yellow Goto field will cause the telescope to move to this position.

• Output is a text window, into which the ongoing measurements are recorded. This is in the same format as the text files from the real telescope. These data can be simply copied and pasted into a text editor and then stored into a file on your own computer.
• Clicking a Start button will wipe the previous data and start to fill this window with the current data.

• all other options are not yet implemented.