Mars Reconnaissance Orbiter Reception - Latest news - updated: (23/12/2007 22:12:55 -0000)
The original page describing the initial reception of MRO can be found here.
Update from 23rd December 2007 : MRO is an easy copy despite massive doppler:
Update from 24th August 2006 - 16:24GMT MRO is a reasonable signal !! see FFT below. Current QRG 8439.347 @ 16:24z
Update from 18 August 2006 - 14:29GMT MRO is very weak!! see FFT below. Current QRG 8439.3112 @ 14:34z
Update from 21 April 2006 - 20:32GMT MRO has a hefty amount of Doppler due to it being close to the bottom of its swing by.
MRO traverses behind Mars at 21:26:09GMT. The FFT below shows the point of cut off at around 1180Hz. At the tine this was received the dish elevation is low and looking through a fair amount of local trees. Mars and the MRO are 170607093.84 Miles from Earth at this point.
The FFT below shows the Doppler shift when MRO is really close to the surface of Mars. The 1KHz steps are caused by the tuning having to be moved downwards to keep track of the signal since its moving fast!
The current frequency is 8438.962 and falling fast. In the FFT below the red ticks are every 10 seconds to give an idea of the speed of the Doppler. Mars is 170542979.64 miles away from Earth, and the signal is still very good, its estimated that it should still be possible top copy MRO when Mars is at its furthest point away from Earth.
An update from 14th March 2006
The MRO went into orbit around Mars on the evening of the 10th of March 2006, and as expected, amateur observers were watching the signal on 8.4GHz and listening to the NASA tv feed to see what was happening.
The picture above shows the MRO carrier as NASA switched from the MRO's HGA to the omni-directional LGA, of course larger DSN antennas could receive the signal, but it was too weak for amateur observers.
The picture above shows MRO emerging from behind Mars, and NASA switching communications back to the HGA - notice the doppler is now moving in the opposite direction at a much slower rate. At the time of signal reacquisition the frequency was 8438.952364 MHz.
This picture shows the MRO signal received when Mars was 137264250 miles from Earth, with the MRO spacecraft orbiting - as can be seen the signal is massive, and easy to copy with a 1.8m dish. The vertical line is a leak at the IF centre frequency. The receive frequency was around 8438.957522 MHz.
This is the dish being used to track Mars and the MRO Orbiter - its an old 1.8m 'NEC' antenna with a home-made adapter plate to allow it to be used with the AZ/EL tripod. On the table is the dual band down converter and associated 24v PSU.