%From:	LPCLUS::DHPJ         "Derek Jones on La Palma" 29-MAY-1993 16:00:51.33
%To:	LPCLUS::MANUALS
%CC:	DHPJ
%Subj:	
%
%Dear Colleagues;   This is LATEX file containing a quick guide for 
%observers using the Peoples Photometer.   I have brought it out in 
%honour of the PP run starting on 1993 February 10 as I have not yet 
%completed the full guide.   Any comments on this guide will be 
%gratefully received....    Derek Jones
%LPVA::PSB,LPVA::VSD,LPVA::HOC,LPVA::APJ,CAVAD::PJR,CAVAD::PJA
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\begin{document}
\begin{center}

{\large\bf Peoples Photometer - Quick Guide}\\

\medskip

Derek Jones\\

\medskip

1993 February 9\\

\end{center}

\bigskip

\large\rm 

\begin{enumerate}

\item {\bf At the beginning of the run}   Make sure that the photometer 
is mounted so that the TV Camera is to the East when the JKT is East of 
the pier.   In this orientation the two apertures of the photometer are
East-West and it is easy to move a star from one aperture to the other.  
 If they are positioned North-South then the backlash in declination 
makes it difficult to move a star from one aperture to the other.   
If the Peoples Photometer is not orientated correctly ask the 
Engineering staff to rotate it.

\medskip

   The Peoples Photometer has two channels called Romeo and Juliet and
there are two pairs of filter slides in routine use.   One pair holds
Johnson $UBV$ and Kron-Cousins $RI$ filters; the sixth hole used to
contain $\beta$ sources for calibration but these are no longer present.
  The second pair contain Str\"omgren $uvby$ filters and broad and
narrow H$\beta$ filters.   The Romeo and Juliet filter slides are not
interchangeable.   Decide whether you want to use the Johnson or the
Str\"omgren filter slides and ask your Support Astronomer to mount them
for you. 

\medskip

There is convenient software in PPAS for two modes of observing:\\

\begin{enumerate}

\item PP22 uses the Peoples Photometer in its two channel mode.   There 
are two apertures separated by 172 arcsec which serve the two channels.  
 While the star is placed in the Romeo aperture the Juliet channel is 
used to measure sky and conversely.

\item PP11 uses only the Romeo channel and is intended for use in 
crowded fields where there is a danger of unwanted stars appearing in 
the sky aperture.

\end{enumerate}

\medskip

 The aperture slide has three positions; the middle one (2) is always
used for TV viewing.   The other positions hold interchangeable plates
pierced by pairs of apertures for PP22 or single apertures for PP11.   A
wide variety of aperture plates is available with apertures from 0.5 to
10 mm.; the JKT scale is 13.8 arcsec/mm.   Decide what apertures you
want and ask your support astronomer to mount them for you.

\item {\bf At the beginning of each night} Check that the dark slides 
are closed.  The EHT to the phtomultipliers and the rest of the 
electronics should be left on day and night.

\medskip

The ICS PE3210 should also be left running at all times.   Check that it 
is running and sign on:\\

\medskip

SI ABC,5,5\\

\medskip

where ABC signifies your initials and 5 is one of the accounts chosen 
from the white board which nobody else is using.\\

\medskip

SET GR 181\\

\medskip

This enables you to dump your data to Exabyte.

\medskip

ADAM\\

\medskip

and follow the prompts for the f/15 focus and the Peoples Photometer.   
This leads you in to the PPAS software.   You will be using either the 
UBV or STR photometric systems and the STRSKY mode.  You will be 
prompted for the name of your data file; it is usual to start with a new 
file for each night and to name it after the day of the month.   If you 
use an old file you must type WARMST.

\medskip

Check that the pneumatics are working correctly by typing PPTEST.   If 
there are any faults reported tell your support astronomer or call the 
duty tech.

\medskip

Check the dark counts by typing DARKCNT.   The dark counts should be 
roughly 4 and 8.   The dark slides are not perfectly light-tight and the 
dark counts apparently rise to about 8,12 when the fluorescent dome 
lights are on.  Run DARKCNT first with the fluorescents on and then with 
them off and check that there is a distinct drop.   This checks that the 
photometer is light sensitive.   If the dark counts are 0,0 you have a 
real problem so call for help.

\medskip

\item {\bf Observation Definition Files}   These are described in the 
PPAS manual but a simple programme can be set up as follows.   Type\\

\medskip

USEALL (observer's initials)

\medskip

and then SETOBJ to form a catalogue of stars and standards you intend to 
observe.   This last step is not essential as you will gradually build 
up a .OBJ file as you enter in the position of each star as you observe 
it.   The important command is:\\

\medskip

SETSEQ P1

\medskip

where P1 is a convenient sequence name and a typical sequence for P1 
would be:\\

\medskip

U-U-8: B-B-2: V-V-2: R-R-4: I-I-8\\

\medskip

which would be suitable for standard stars.   You can set up further 
sequences P2,P3 etc with 2* and 4* the exposures for observing fainter 
stars.   It is best not to have sequences totalling more than a hundred 
seconds because defective telescope tracking may carry the star 
(partly) out of the aperture.

\medskip

  The RUN files are not generally used.\\

\medskip

\item {\bf Twilight} With the telescope in the zenith type:\\

\medskip

SLIDES 1 2 1 1 or SLIDES 1 2 3 1\\

\medskip

Depending on whether you want to use the aperture(s) in position 1 or 3.
If in doubt use the smaller aperture(s).   Turn up the TV gain carefully 
until you can see the apertures clearly delineated by the twilight sky 
shining through them.   Use the `DRAW CIRCLE' command with the Grinell
to delineate the apertures.   If you have trouble with the Grinnell you 
can draw them in with felt tip but this is not so good because of 
parallax.
  
\item  {\bf The first standard of the night}   Remember to open the dark 
slides.  Send the telescope to the first standard of the night and view 
the whole field through the TV.   Type:\\

\medskip

SLIDES 1 2 2 1\\

\medskip

and turn the TV gain up carefully and you should see the star somewhere 
in the field.   SNAFU the telescope to the Romeo aperture; this is the 
left hand one on the screen which is designed to be on the telescope 
axis.   When you are satisfied with the centering in the Romeo aperture 
press the ACK button on the telescope console.   Then type SNAFU/A and 
centre the star in the Juliet aperture.  When the star is centered again 
press ACK a second time.   Pressing `NOM' and `A' on the telescope 
console should place the star in the Romeo and Juliet Apertures.  Forget 
the Juliet aperture if you are only going to use PP11.

\medskip

DEFSEQ P1 if this the sequence you use for standards

\medskip

PP22 or PP11 and follow the prompts.

\item {\bf Subsequent Stars} Enter their positions at the telescope 
console and slew the telescope to them.   SLIDES 1 2 2 1 will show the 
whole TV field and enable you to acquire the star.   There should be no 
need for further SNAFUs.   If the star is fainter than the standards 
then use a sequence with longer integration times.

\item {\bf The PC Data Logger}   There is no log kept automatically such 
as there is for the CCD Camera.   You are recommended to use the PC data 
logger in the console room; instructions are given below.
If you are 
really old-fashioned and are not afraid of writer's cramp you can enter 
the observations in a ledger.

\item {\bf Continuous modes}   MONITOR, SLCONT and FCONT are continuous 
modes which are described in the PPAS manual.    These programs do not 
set the aperture automatically as PP22 and PP11 do.   Remember also that 
there is no auto-guider with the Peoples Photometer and the centering of 
the star should be checked every 100 seconds or so.

\item {\bf Warnings}

\begin{enumerate}

\item  Only observe if you are confident that conditions 
are photometric {\it ie} if there are no clouds in the sky.   The 
Peoples Photometer does have a beam-splitter mode for use in 
non-photometric conditions but there is no software in PPAS to exploit 
it.

\item Although the filters are designed to reproduce the standard 
photometric systems they are not absolutely correct so observe ample 
standard stars to determine the colour equations.

\item For accurate photometry it is essential to determine the 
extinction each night and not to rely on mean values.   It is good
practice to enquire the values determined in V by the CAMC.   To the 
first approximation the variations in extinction can be assumed to be 
gray.

\end{enumerate}

\item {\bf Dead-Times}  The dead-times determined in 1992 December 
were:\\
   Romeo   48.5 nanosec\\
   Juliet  45.3 nanosec\\
Each with a standard error of 1 nanosecond.\\

\item {\bf End of the Night}

\begin{enumerate}

\item Close the Dark Slides

\item FITSOUT your data file to Exabyte

\end{enumerate}

\end{enumerate}
\begin{center}

\vspace{5mm}

{\bf Appendix - JKT PC Data Logger}\\

\vspace{5mm}

\end{center}

\begin{enumerate}

\item   The JKT has a PC/AT Data Logger which can be used to copy parameters 
from the JKT INFODISP screen to its hard disk and output them to its line 
printer.   It has no connection to the instrument computer but instrument data 
can be entered by hand at the console as observations are made.

\item   The printer is an Epson LQ-1050 and the replacement ribbon is an Inmac 
Good Impression 6419.   We hold replacement ribbons and the one in the printer 
was last replaced on 1992 November 29.   Set the paper division exactly on the 
lower rollers.

\item The PC will normally be found on, and displaying the JKT prompt in
 blue at the bottom left hand corner.

\item Check that the PC calendar is correct by entering 'Date'.  The PC will 
display the supposed date.  If correct press $<cr>$, otherwise enter the 
correct date.

\item Check the PC clock is correct by entering 'Time' .   This is often wrong 
by a few seconds.   Set a time about 30 seconds in advance and $<cr>$ on the 
exact second.

\item  To start the program enter LOG $<cr>$ at the keyboard

\item  The functions available from the keyboard are:

\begin{itemize}

\item  1.   Change Header Parameters

\item  3.   Edit/Delete one entry in the log

\item  4.   Print the log

\item  5.   Enhancements to this software

\item  R    New Run

\item  X    End Program

\end{itemize}

\item   Change Header Parameters if necessary at the beginning of every night, 
press R for every observation and X at the end of every night.

\item  The function switches are as follows:

\begin{itemize}

\item   F1  Help (No help defined)

\item   F5  List

\item   F7  Run?

\item   F8  Last Run (Right Arrow)

\item   F9  Previous Run (Left Arrow)

\item   F10 Next Run (Right Arrow)

\end{itemize}

\end{enumerate}

\vfill

\end{document} 
