The Sun, Moon and Earth System
This is a big electro-mechanical, working model of the sun, moon and earth system. It shows four motions -
- Earth's rotation
- Earth's revolution
- Moon's revolution
- Earth's precession motion
Various phenomena occurring due to the above motions can be shown using the model -
- occurrences of eclipses
- occurrences of eclipses only on some full moon and new moon days
- Kepler's laws for planetary motion
- occurrences of six month long day and six month long night on the north and south pole of the earth
- occurrences of seasons on the earth
- precession motion of the earth's axis
- changing of the north pole star of the earth
- rotation of the equinox and solstice points
- the same side of the moon constantly facing the earth irrespective of its revolution around the earth
Universe
This is a graphical 3D simulation of the orbital mechanics of the planetary motion in the solar system and galaxy. It specifically concentrates on the phenomenon related to the sun, moon and the earth. The different phenomenon that can be shown in the simulation are --
- Why does the day-night cycle occur on the earth
- Why do eclipses occur ?
- Why do eclipses occur only on some full moon and new moon days ?
- Why is there a six month long day and a six month long night on north pole and south pole of the earth ?
- Kepler's first and second law for planetary motion
- Rotation of equinox and solstice points
- Rotation of moons orbit which causes saros cycles
- Precession motion of the earth
- Why does the north pole star change its position ?
- Parallax method for the measurement of distances of stars from the earth
- Why does the Milky Way belt lie in the North-South direction ?
Antenna Radiation pattern plotter
Initially this was a standalone program written for DOS using Turbo
C++, but now it is a part of a bigger project named
While running on DOS, it used SVGA BGI driver to run at 1024x768. It was able to draw the full and sectional 3D views of the different antennas in the form of a grid surface. It used the 3D rendering equations derived by me for the 3D simulation program Universe. Around the same time, I had written a program to plot the horizontal pattern of a 2 element phased array. By pressing a key the user could change the phase angle by small increments and could instantaneously see its effect on the radiation pattern. The change of the direction of the major lobe along with the phase angle could be clearly seen. Phased array will be soon be added to the new program.
Fast Fourier Transform
The user can draw an arbitrary time domain signal on the graphics surface using mouse. On every change in the time domain signal, the program will draw its FFT & the reconstructed signal with certain cutoff frequency. The cutoff is determined by a number in a spin box on the control panel on the left side of the graphics surface. The range is 0 to 315. The cutoff frequency is the value in the spin box divided by 100. For example, if the value in the spin box is 50, the cutoff will be at 50/100 radians. The cutoff will be clamped at frequency of PI radians.
