CURRENT AFFAIRS

Detailed explanation-1: -Washington: Nasa’s Magnetospheric Multiscale mission (MMS) has set the Guinness World Record for highest altitude fix of a GPS signal-at 70, 000km above the surface of the Earth.

Detailed explanation-2: -High earth orbitFrom geostationary to the moon, 363, 104 km out, but that’s not even earth’s most distant orbiter: A NASA satellite studying solar wind has the highest point in its orbit at 470, 310 km-and it’s also the lowest-flying satellite at the other end of its elliptical orbit, coming as low as 186 km.

Detailed explanation-3: -GPS is a system of 30+ navigation satellites circling Earth. We know where they are because they constantly send out signals. A GPS receiver in your phone listens for these signals. Once the receiver calculates its distance from four or more GPS satellites, it can figure out where you are.

Detailed explanation-4: -Signals. Each GPS satellite transmits data on two frequencies, L1 (1575.42 Mhz) and L2 (1227.60 MHz). The atomic clocks aboard the satellite produces the fundamental L-band frequency, 10.23 Mhz. The L1and L2 carrier frequencies are generated by multiplying the fundamental frequency by 154 and 120, respectively.

Detailed explanation-5: -The GPS signal has two components at center frequencies of 1575.42 MHz and 1227.6 MHz. The use of L-band results in smaller ionospheric delay effects. Relativistic effects are partially compensated for by offsetting the 10.23 MHz clock rate. Both P-code and C/A-code are used to modulate the signals.