BAIT manual page

Warning Much of this is Wrong

BAIT Operation

This document describes how to acquire astronomical images using the Berkeley Automated Imaging Telescope (BAIT) via Internet Mail and FTP (File Transfer Program). The purpose of this html page is to give an overview of the facility and enable the user to prepare simple requests. More detailed information can be found in the man pages mentioned below.

PRELIMINARIES

You must be added to our list of authorized users before an observation can be accepted. Send a (human readable) note by e-mail to baitmgr@bait.berkeley.edu stating who you are and what you wish to do. This Internet address can also be used for asking questions about the system and its capabilities. Bug reports are appreciated.

PREPARING YOUR REQUEST

An observation request is a text file with a keyword = value syntax. You may prepare this with any text editor. Below is a request for a single flat-fielded, five minute, R band exposure of the Orion nebula.

OBSERVER= 'Tycho Brahe'
SENDMAIL= T
MAILADDR= 'knudstrup@sweden.org'
PROCEDUR= 'photo_proc'
OBJECT = 'Orion Nebula'
RA      = ' 5:35:11.0 ' 
DEC     = '-5:23:16 ' 
EPOCH =     2000 
FILTERS = 'R'
EXPTIME = 300.0
END

The first keyword tells the system who is requesting the observation. You must fill in your own name and enclose it in single quotation marks. Keywords and values are case sensitive; keywords are always capitalized. Comments can start anywhere after a # sign or / sign. The next two keywords determine the disposition of the data: in order to be informed when the observation is made, SENDMAIL must be set to the letter T (this is a Boolean True); and your Internet address must be placed as the value for MAILADDR.

The PROCEDUR (note odd spelling) keyword specifies how you want your observation made. The most common value is 'photo_proc' which takes an image that has been bias and dark current compensated and flat field corrected.

The OBJECT keyword must be set to the name of your target; again it must be enclosed in single quotation marks. The Right Ascension and declination of your target must be specified in Babylonian format (hour minutes seconds format delimited by colons and no included spaces) . The equinox (year) of the coordinates must also be specified using the (slightly misnamed) EPOCH keyword. The optical filter name must be supplied as well as the exposure time in seconds. The section CAPABILITIES below tells you how to find the names of the available filters. Finally the file must finish with an END statement.

When the request file is complete send it by e-mail to:

twenty@bait.berkeley.edu - for the twenty inch telescope thirty@bait.berkeley.edu - for the thirty inch telescope

You will then receive (in less than a few hours) a reply informing you whether your observation has been scheduled or rejected. You will also be assigned an id code (REQID) for the request. (This code is derived from the date and time that the request was received.)

If errors are present an attempt will be made to provide diagnostic messages. These must be corrected and the file re-submitted before an observation is scheduled.

RETRIEVING YOUR DATA

If all goes well you will receive a morning message in a few days that is similar to the following:

Your BAIT observation(s) from the Twenty inch telescope are available on flipper@berkeley.edu

directory     filename      filter exptime object 
pub/bait/Dec03 Dec33bzi.fts.Z V 1500.0 SN_1993ad 
pub/bait/Dec03 Dec33cmx.fts.Z R 900.0 SN_1993ad 
pub/bait/Dec03 Dec33cuh.fts.Z I 900.0 SN_1993ad

The message tells you that your data is on the machine: 'flipper.berkeley.edu' in the directory: 'pub/bait/Dec03' and has the filenames Dec33bzi.fts.Z etc. To retrieve the above data you must then enter the following commands (without the prompts) from the directory in which you want to import the data:

% ftp flipper@berkeley.edu
Connected to flipper.berkeley.edu.
220 flipper FTP server (SunOS 4.1) ready. Name
(flipper.berkeley.edu:yourid): anonymous
331 Guest login ok, send ident as password.
Password:

230 Guest login ok, access restrictions apply. ftp> cd
pub/bait/Dec03

 ftp> binary
 ftp> get Dec33bzi.fts.Z
 ftp> get Dec33cmx.fts.Z
 ftp> get Dec33cuh.fts.Z
 ftp> quit
 % uncompress Dec33bzi.fts Dec33cmx.fts Dec33cuh.fts

The last command converts the file from its compressed form to native FITS.

REQUEST MESSAGES

In addition to the disposition of your data, the morning message may contain information about your request file. If a line contains the string 'has_been_completed' it means that you have been sent all the data that you have requested and that your request file has been retired. The request file above specifies (implicitly) that only one observation is made and so you will receive such a message after the data file has arrived.

If the string 'has_expired' is present it means that you have specified and ending date (see DAYEND) and that day has passed without the requested number of observations (see NUM-OBS) being completed once again the request will be retired.

The string 'observation_failed' means that the system attempted to observe your target last night, but for some reason was unable to take data. This may be have been due to poor weather, or equipment failure. These messages do not mean that they request is no longer active; it will be attempted again tomorrow.

CAPABILITIES

If you want to find out about the telescope and observatory you can retrieve the file ait.config by mailing the following very small request:

PROCEDUR='get_config'
END

To the e-mail address of the telescope you wish to learn about (e.g. thirty@bait.berkeley.edu) and you will get a file similar to:

OBSERVAT='Leuschner'
OBSLAT =       37.91833    / Leuschner latitude in decimal degrees
OBSLONGH=       8.1437972 / Leuschner longitude in hours 
OBSELEV = 304.             / Leuschner elevation (m) # 
INSTRUME='B.A.I.T.' # #telescope parameters 
TELESCOP='Thirty inch'
TELAREA = 4560.0            / telescope collecting area (cm^2) 
TELSCALE= 33.88             / scale in arc seconds per mm 
TELLIMN = 90.0             / North declination limit (decimal degrees ) 
TELLIMS = -31.0 / South dec lim 
TELLIME = -100.0           / East hour angle limit
TELLIMW = 100.0            / West hour angle limit 
TELLIMA = 16.0           / altitude limit
DETECTOR='Ford Aerospace'
CCDPIX= '20.0 20.0'        / pixel size along columns and rows (microns) 
CCDSEC = '[1:516,1:516]' / number of columns and rows
#filter parameters
 #the number is the filter bolt number which starts at 0 #define the names
are CASE sensitive so that 'u' differs from 'U' #filter format is 'name
eff.lambda(Angstroms) equiv.width(Ang) exptime' # the UBVRI set is from
Schild,PASP,1983,95,1021.

NFILTERS=8                       / maximum number of filters
FILTER00='clear 5000 4000 1 ' / numbers a guess, not measured 
FILTER01='none 5000 5000 1 '    / numbers a guess
FILTER02='B     4400 800 60 '    / numbers a guess 
FILTER03='R     6700 1000 20 '    / number a guess 
FILTER04='I     8000 1000 20 '    / number a guess 
FILTER04='I     8000 1000 20 '    / number a guess
FILTER05='V     5500 900 40 '    / numbers a guess
FILTER06='U     3650 700 60 ' / numbers a guess 
FILTER07='ir    9000 2000 10 ' / numbers a guess

The file conktains the telescope limits in declination and hour angle; the latitude and longitude, the filter names, the size and nature of the CCD as well as various internal keyword/values.

OTHER REQUEST FILE FEATURES

There are many other features available for tailoring your request that are described in the request document. The DAYSTART/DAYEND keywords can be used to limit the observations to a specific interval. The NUM-OBS keyword can be used to request a specific number of observations (at one per night). The INTERVAL keyword an be used to observe a target once every specified number of days (on average).

Multiple observations that must be taken together can be included in the same request file by including extra lines after the END statement. Only keywords that change need be included. The following example is a request for two images with different filter and exposure times of the Orion nebula. When successful you will receive two images with different DATIDs.

OBSERVER= 'Galileo Galilei'
SENDMAIL= T
MAILADDR= 'galileo@cosimo.pisa.edu'
PROCEDUR= 'photo_proc'
OBJECT = 'Orion Nebula'
RA      = ' 5:35:11.0 '
DEC     = '-5:23:16 ' 
EPOCH =     2000 
FILTERS = 'R' 
EXPTIME = 30.0
END 
FILTERS = 'B'
EXPTIME = 90.0
END

To observe planets or asteroids (whose coordinates change with time) prepare a request similar to the following:

#this is a sample request file for looking at pluto OBSERVER= 'Johannes Kepler'

 SENDMAIL= T
 MAILADDR= 'JKepler@orbit.graz.edu'
 PROCEDUR= 'doplanet'
 OBJECT = 'pluto'
 FILTERS = 'clear'
 EXPTIME = 300.0
 END

The OBJECT specifies the name of the major or minor planet. No coordinates are needed since the PROCEDUR 'doplanet' will calculate them at the time the observation is made. However, you must still fill in the exposure time and filter.

PROBLEMS

The most common problems in writing a request file result from the rather strict format. In particular the presence or absence of single quotation marks around strings. The PROCEDUR, MAILADDR, OBSERVER, OBJECT, RA, DEC all require single quotes (') and not (`) or ("). The spelling of PROCEDUR and FILTERS also leads to problems.

You may receive the message you are not in our list of permitted users, even after you have registered (See Preliminaries above), because you have sent the request from a different computer than the one you originally used. This is an unfortunate result of our security system.

If you lose track of what you have requested: a complete list of targets for the telescope can be retrieved by mailing the following request to the relevant e-mail address:

PROCEDUR='get_targets'
END

A tentative list of the scheduled targets for the telescope can be retrieved by mailing the following request to the relevant e-mail address:

PROCEDUR='get_list'
END

The target list is created around noon local time and is updated after observations are made and accepted. Observations that are scheduled but not observed are denoted 'selected'; those completed are denoted either 'done' or 'error' depending on whether they were observed without telescope error. Those denoted 'nospace' may not be observed since the schedule is too busy.

To delete your request you can send a file listing the REQIDs and the PROCEDUR='del_request'. For example

PROCEDUR='del_request'
REQID='Feb43ebe'   # CW_Tauri REQID='Feb43ebg' # DG_Tauri 
REQID='Feb43ebk'   # HD45677 END Note: the requests will only be

deleted if their value of MAILADDR matches the Return path of the incoming mail.

If you are patient and receive a message 'observation_failed' and wish to find out why, look in the file 'insgen.log' in the current data directory (e.g. pub/thirty/Dec07). This file contains a listing of the nights work and is for experts only.

Currently there is very little control of quality of the data. Severely bad weather will cause the telescope to shut down, however, observations are not stopped due to intermittent cloud cover. If the guider is operational, clouds will cause the acquisition to fail and you will get a morning message.

GUIDING

The twenty inch telescope is capable of guiding, while the thirty inch is not. The default mode for the twenty inch is to guide on all images. A guide star will be selected automatically when you submit a request; the brightness of the star will be reported when you submit the request.

DATA FORMAT

The images are in FITS (Flexible Image Transport System) described in Astr. Ap. Suppl. v44, p363, 1981. Our data contain an extensive header filled in at the time of exposure. Information about the object, the telescope, the weather and the orientation and scale of the chip are entered. See the photo for a discussion of the keywords.