| REMOBS - NORMAL | REMOBS - RFI |
|---|
Note: Click here when using the combination Epoch = AZ/EL, Scan type = MOSIAC, and Antenna offsets (holography mode).
| After Logging onto YONDER as remobs | ||||||
| YONDER > xhost +leon +neol +nemesis | ||||||
| YONDER > telnet leon {as self} | ||||||
| LEON > set host LEON | ||||||
| LEON > remobs {as observer} {YONDER,TCPIP,AUTO} | ||||||
| NOEL > |
CAOBS > | NEMESIS > xhost +caccc | CAMON > /baseline | VIS > sel 12,34,56 {or 45AA, etc. try shortest baseline} | WINDS > /xs | |
| NOEL > |
CAOBS > | NEMESIS > rlogin caccc -l corr | CAMON > | VIS > dpa-t | WINDS > | |
| NOEL > |
CAOBS > | CACCC > setenv DISPLAY yonder:0.0 | CAMON > | VIS > time utc | WINDS > | |
| NOEL > |
CAOBS > | CACCC > xterm &; xterm & | CAMON > | VIS > hist 30, scale, ... | WINDS > | |
| AFTER CHECKING WITH THE CONTROL ROOM | ||||||
| NOEL > |
CAOBS > | CACCC > cacor {TkCor GUI} {do this first} | CACCC > | CAMON > | VIS > | WINDS > |
| NOEL > | CAOBS > caobs | TKCOR > | CACCC > | CAMON > | VIS > | WINDS > |
|
Choose a time when interference is minimised, (LEO orbits - email
Mitch), to let attenuator
settings settle and to calibrate the phases, delays and gains. Assuming that the calibrator is the first source, check and correct attenuator levels | ||||||
| NOEL > |
CAOBS > set file filename | TKCOR > | CACCC > spd | CAMON > | VIS > | WINDS > |
| NOEL > |
CAOBS > track 1 {calibrator} | TKCOR > | SPD > | CAMON > | VIS > | WINDS > |
| NOEL > | {May need to set coarse attenuation. Set to final levels
before observing} CAOBS > set coarse ca0n jklm {(0-3)} | TKCOR > | SPD > | CAMON > /stats; /samp | VIS > | WINDS > |
| When samplers are good and ONLY IF delays are stable | ||||||
| NOEL > cacal | CAOBS > | TKCOR > | SPD > | CAMON > | VIS > | WINDS > |
| NOEL > | CAOBS > stop | TKCOR > | SPD > | CAMON > | VIS > | WINDS > |
|
The interference is likely to vary so much that the automatic attenuator level
process will not stablise. For this reason they are disconected and set manually
during the observation. The main thing is to try to keep the gated total power fairly
equal for all antennas and away from 0 and 5. Generally setting SAMPLER NEG ~
SAMPLER POS during low levels of RFI achieves this. At times of strong RFI this is bloody
hard and I suggest leaving it (most LEO RFI comes in short pulses when the fringe
rotation decorrelation is minimised. This can break down at shorter baselines).
The coarse attenuator settings may need to be changed again, particularly for strong signals. In some circumstances the automatic setting of the servos which control the A-D converter inputs may need to be turned off (set servo_off). I haven't used this before, so consult user's guide/staff. | ||||||
| NOEL > | CAOBS > disable auto | TKCOR > | SPD > | CAMON > /samp; /stats | VIS > | WINDS > |
| NOEL > |
CAOBS > track 1 {calibrator} | TKCOR > | SPD > | CAMON > /samp; /stats | VIS > | WINDS > |
| NOEL > |
CAOBS >
set atten ca0# jklm {jklm are the polarisations of the two IF's. Decrease if "SAMPLER NEG" is low. range=[0-7]. below zero, need to change coarse atten.} | TKCOR > | SPD > | CAMON > /samp; /stats | VIS > | WINDS > |
| When things look OK, observe. You can change the attenuator levels while observing, but don't change the coarse setting. | ||||||
| NOEL > |
CAOBS > > stop > corr closefile > start 1/100 > ... > stop > corr closef > enable auto > stow | TKCOR > | SPD > |
CAMON > |
VIS > | WINDS > |