[evlatests] Preliminary Wobble Report

[Rick Perley]

Ken ran three tests this afternoon, as described below.  I've taken a 
quick look at them, looking for obvious wobbles. 

Starting with the second: (3 kHz fundamental)

Wobbles are seen on only two baselines: 
    a) 9 x 27 (E2 -- E10), a strong pure sinusoid in phase only, pk-pk 
amplitude of 4 degrees. 
    b) 2 x 10 (E2 -- N14), in amplitude only, a beat between two tones, 
one of 15 second period, the other of 0.5 second. 

For the first test (20 kHz fundamental)

Wobbles seen in only one baseline:  2 x 10 -- with characteristics 
similar to that noted above. 
However, antenna 9 was 'out' of the array at the time of this test, so 
the phase wobble, if present, could not be seen.

    For the third test (Brent's algorithm)

No obvious wobbles are visible.  The phase wobble on 9 x 27, if present, 
is less 1 degree pk-pk.  The amplitude wobble on 2x10 might be present 
-- if so it is of much lower amplitude. 

    A Fourier analysis is needed for a most discerning judgment. 

   

Three data sets are available.  Two use the standard LO offsets,
fundamental*antID; the third uses Brent's improved algorithm,
13+3*antid+.1 kHz.

C_osro_short_000 starts at 2047 UT, uses a fundamental of 20 kHz.

C_osro_short_001 starts at 2053 UT, uses a fundamental of 3 kHz
to match the following test.

SOFTWARE.C_osro_short starts at 2114, stopped at 2136 UT.  Uses
Brent's inmproved algorithm.