Useful Commands (and other hints) for Bolometer Observing

1. If you are at a terminal that has a LOCAL> prompt, type C or C VAX1. This should give you the VAX's login prompt.

2. Log into the computer and type UIP.

3. BOLO 10 /WAVE=850 sets bolometer mode, 10 sec integrations and logs the wavelength as 850 mu. On bright sources BOLO 2 can be used. Note: while the /WAVE=850 will log the wavelength as 850, it has no influence whatsoever on the filter set in the bolometer. That still has to be done by hand.

4. DATA 24MAY90.DAT opens a new data file (with the name 24may90.dat) or reopens an old one (if you happen to have one by that name). Make sure that you have set yourself to bolometer mode before opening the data file (i.e. typed BOLO), bolometer data files and spectral line data files are incompatible. (You may be able to write bolometer data into a spectral line data file, but reading it is a different problem). Also, in case of a new file it will prompt you whether you want to open that file (you may have made a typo). Answer Y to that prompt if you want to open the file, the default behavior (that you get on typing ) is to not open a new file.

5. POINT BOLO puts the pointing offsets for the bolometer into the computer. The values we have found are FAZO ~-5 and FZAO ~-50. The pointing needs to be checked frequently using FIVE or JOY on a bright source (>3 Jy at 1.3mm, > 10 Jy at 0.8mm).

6. A version of the JCMT continuum pointing catalog is available as CAT_DIR:JCMT_POINT.CAT. The ASCII listing of this catalog can be found in CAT_DIR:JCMT_POINT.LIST.

7. The white notebook labeled "Unlabeled but valuable stuff" contains lists of pointing sources and approximate 1mm fluxes, and planet fluxes. (I haven't seen it for a long time, but there is a binder labelled "Bolometer Manual" now)

8. PLANET URANUS points telescope at Uranus. (Use the PLANET command for moving objects)

9. OBSERVE 3C273 points telescope at 3c273. (Use the OBSERVE command for fixed objects)

10. SECONDARY 60 3.723 sets the secondary's chop throw to 60 arcseconds and the frequency to 3.723 Hz in the VAX. Right now you have to set the chopper control manually. To do this UIP will tell you what to set the amplitude and DC offset on the HP 33120A waveform generator to. The frequency has then to be set to what you specified in the SECONDARY command as well. You should be shown this by staff before attempting in on your own.

11. When you first get to a source the source will be in the middle between the two beams (if you're pointed right). A CHOP 1 command will put in the chop_AZO (left half, about in the middle of the screen) and leave you with the source in the positive beam (also at positive offset) in the end. If you want to check whether you can see your source without executing an observation, type AZO . You should then be able to see your source on the strip chart (if it is strong enough) to roughly point up on it with the JOY command (see below).

12. FIVE 15 1/CYC=2 peaks up on an object with 15 arcsec (half-beam) spacing, two integration cycles and suggests new FAZO and FZAO values. (15 arcsec is half-beam for the 30 arcsec Winston cone, for smaller beams you may want to use smaller step sizes, or of course bigger ones for larger sources. Which cone you have is written on a note on the bolometer itself, together with which filter is in which slot).

13. JOY 3 puts you into joy stick mode (using arrow keys on terminal) with 3 arcsec steps. The offsets will show up in the AZO and ZAO fields on the (b/w) antenna computer screen (left half, upper third). AZO and ZAO are used in e.g. five point observations as well, they won't stay in. If you find your source slightly off, put the offsets into the FAZO or FZAO respectively.

14. CHOP 2 takes an integration with 2 cycles, cycles consisting of + - - + (i.e. if you set the integration time to 10 you get 40 seconds worth of data). The chop throw is set with the SECONDARY command now, so the second parameter on the CHOP command doesn't exist anymore.

15. CAT GWINN opens a catalogue named GWINN.CAT.

16. SOURCE SGRASTAR HHMMSS.SS DDMMSS. enters a source named SGRASTAR into your catalog (this is the catalog you opened last, i.e. if you haven't specified a catalog with the CAT command above, your own SYS$LOGIN:PRIVATE_CATALOG.CAT). Do not use ``+'' for positive declinations. Do not leave spaces between fields in coordinates. Default are 1950 coordinates.

17. RUN [JBK.BOLO]EXAMINE2 lists data in various ways.

18. RUN [JBK.BOLO]DUMPBOLO lists total data.

19. TAU 1DAY plots 225 GHz tau for current day.

20. Remember to look at the computer manual or use on-line help if you have any questions. (Usually on-line help is more up to date that any manual you find lying around).

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