Guardian of Motherland's Skies

This image= Photoshop+Russian Air launched Weapons by Midland Publishing+Blender 3D.


Hmm a photo depicting one proud young Vihenian Airforce pilot in 1967. Climbed to his Shelenia Lerina interceptor aircraft and guarding his motherland's sky.

His plane is armed with four R-98 Semi active radar homing missiles and two close fighting R-13M heat seeking missiles. There are also 23mm NR-23 gun armament.

In front of his seat lies one of the most advanced airborne intercept radar in Vihenia that developed for mass production. Referred as I-20 Sapfeer. The Radar is a pulse doppler design, interleaving high and medium PRF for searching target. It has look-down shoot down capability and some anti jamming features.

The antenna of this radar is a twist cassegrainian type, with polarization screen at the front of the antenna to rotate the polarization of both incoming and outbound wave, thus practically eliminating aperture blocking previously encountered in other radar that uses conventional cassegrainian focus where the outbound wave is not polarized..thus creating aperture blockage and distort the radiation pattern of the radar.

Dimension of the antenna is 680mm in diameter with 34 Db gain in three centimeters wavelength

Sapfir is capable of transmitting over 4 Kw of peak power with 30% of duty cycle (thus 1,2 Kw of average power), the receiver is a superheterodyne based with noise figure of no more than 8 Db. Cooling of the radar set is liquid based, which dissipates the excess heat through heat exchanger that dump the heat to the fuel. The Radar is capable to provide CW (Continuous Wave) illumination for semi-active missile, through separate horn

In modes of operation it has over five distinct air-to air modes, two modes for searching targets while the remaining three are air combat modes.

Detection range performance for typical fighter sized type with effective reflecting area of 3 square meters at head on course are no less than 60-75 Km in favorable weather condition.

In look down shoot down mode for detecting target flying at low altitudes, detection range performance is markedly lower due to the ground clutter that compete with target signal strength.

For above mentioned condition the detection range for the same approaching fighter type target is around 30-40 km or less.

Receding fighter type target or moving at speed slightly higher than minimum resolving doppler capability of the Radar practically halved the detection range against the approaching one.

Hovering helicopter type target is not currently detectable due to processor limitations which cannot resolve doppler shift modulation generated from the helicopter's main or secondary rotor. Future radar planned to achieve operational status in 1970 however may not have this limitations.

Below the Radar set lies another marvel in Vihenian fighter sensor technology, the "Buk" Infra red search and track (IRST) system. Buk utilizes detection elements made of new HgCdTe (Mercury-Cadmium-Telluride), working in long IR waveband (8-12 micron band) It is capable to passively detect tail aspect afterburning fighter type target from over 50 km range in high altitude and provide fire control solution for gunnery and missile employement.

Due to its passive nature, the enemy may not aware of its operation, allowing our pilot to conduct "stealth approach" and destroy the target with infra red homing missiles.

Range measurements is provided through Laser range finder. However ranging process in excess of 10-20 km is not possible due to laser power and receiver limitations. The laser ranging mode however is usually employed for dogfighting, for high accuracy of machine gun employement.