TCS User Catalog format}{ To: Palomar users
From: J. R. Henning
Date: 23 Sep 97

Overview
This memo describes the various ways object coordinates can be entered into the Telescope Control System (TCS) for the Palomar Hale telescope, and how observers can optimize their observing time by making object positions easily accessible to the telescope operator.

User catalogs
Up to ten User catalogs may be installed for observers' use. User catalogs are installed by Palomar Staff from observer-supplied input files; the format for these files is described later in this memo.

Input files may be transported to Palomar on 8mm tape, on 3-1/2" diskette or over the Internet. Tar, dd and VMS backup tape formats are supported. PC- and Unix-format diskettes are supported. For Internet transfers, Palomar intends to provide anonymous ftp so files may be sent to Palomar's Norris workstation in advance of a run (this is not yet implemented); alternatively, observers may retrieve files from their home sites after arriving at Palomar. In all cases the file(s) are installed on Norris for transfer to the TCS.

We at Palomar believe the User catalog is the most effective way to provide observing coordinates to the telescope operator, especially when more than a few objects are to be observed. We wish to encourage observers to use this facility and will entertain suggestions to make these catalogs easier to install and use.

Keyboard-input coordinates
The telescope operator can enter coordinates at the keyboard. These coordinates may then be used immediately for pointing the telescope or they may be entered into the Scratch catalog for later retrieval. The Scratch catalog has room for up to 100 positions.

While this method allows input of new coordinates at any time, it may slow observing if done when the coordinates are actually needed. Transcription errors are also possible.

Coordinates input via instrument computer
The TCS interface to instrument computers allows these computers to send coordinates directly to the TCS. Such coordinates may be used immediately for pointing the telescope or they may be entered into the Scratch catalog for later use.

"Grabbed" coordinates
The instantaneous position of the telescope may be acquired by the telescope operator at any time as an input position. The coordinates may then be entered into the Scratch catalog.

Interpolated coordinates
When a non-sidereal-rate object is to be observed, its instantaneous position and tracking rate can be derived when its positions for 0h UT before observing time and 0h UT after observing time are known. The TCS can calculate the position for the object at an arbitrary time within the 24-hour window. This is done by a simple linear interpolation.

The position may be used immediately for observations, or it may be saved in the Scratch catalog for later use.

Format for user catalog input files
An input file consists of a series of newline- and/or carriage-return- delimited records. Each record consists of a series of whitespace-delimited fields. (Whitespaces are one or more space or tab characters.)

Each record (line) must contain a single catalog entry. Format is basically free form within the guidelines described below.

Required Fields (listed in required order):

  1. Index number or name (one or more fields). See Index Number Election below for more information.
  2. Right ascension coordinate (three fields): integer hours 0 to 23, integer minutes 0 to 59, integer or floating seconds 0.0 to 60.0.
  3. Declination coordinate (three fields): integer degrees -50 to +90, integer arcminutes 0 to 59, integer or floating arcseconds 0.0 to 60.0. The plus sign on positive declinations is optional.
  4. Equinox of coordinates (one field): integer or floating year 1500.0 to 2500.0, or 0 for apparent coordinates. Besselian or Julian equinox may be specified by prefixing B or J (eg, B1950.0 or J1997.5). If there is no prefix Julian is assumed, except 1950 is assumed to be Besselian.

Index Number Election:
Entries in the User catalog may be accessed by index numbers. To enable this mode the word "INDEX" or "SEQUENCE" (upper or lower case) must appear on a separate line before the first catalog record, and the first field of each record must be a unique positive integer in the range 1 to 99999. Numbers need not be consecutive nor in order.

If index numbers are not enabled entries will be accessed by name, and the first field(s) of each record must constitute a label (all fields up to the first RA field will be considered part of the name). The maximum overall length is 20 characters including all name fields and spaces; anything additional will be truncated.

If index numbers are used the name is optional and, if present, must follow the index number and precede the RA.

Optional Fields:
At most one of the following options may be used. Option labels may be upper or lower case. The option, if present, must follow the equinox field. The option field may not contain embedded spaces.

Proper Motion: the format is "PM=,", where is an integer or floating value in units of 0.0001 seconds/year and is an integer or floating value in units of 0.001 arcseconds/year.

User Tracking Rates (RA in arcseconds/hour): the format is "RATES=,", where and are integer or floating values in arcseconds/hour.

User Tracking Rates (RA in seconds/hour): the format is "RATESS=,", where is an integer or floating value in seconds/hour and is an integer or floating value in arcseconds/hour.

Additional:
Blank lines are ignored.

Comment lines may be added anywhere within the file. A line is considered a comment if the first non-whitespace character is '!'.

An input file may contain up to 99,999 catalog entries.

It is an error for any record to contain more than 20 fields or more than 255 characters. No field may contain more than 20 characters.

The input file is parsed by the READuser command in the TCS to create a User catalog. If an error is encountered, the line and field containing the error are reported and creation of the catalog is aborted. The observer should then edit the input file before READuser is run again.

Examples

! Catalog with index numbers
INDEX
557 PKS 0957+00  09 57 43.8   00 19 50   B1950.0
	
! Index numbers, no name field
index
1008    04 58 41.3  -2 3 35.0  2000.

! Catalog without index numbers
sn 1986 a   10 43 55.8  +14 0 48.  1950
	
! Proper Motion
2030  sao132680  5 54 29.5  -3 45 40  B1950  pm=-2,-19
	
! Non-sidereal object
2013  Object X   12 11 45.2  -15 37 24.0  0.0  rates=23.4,-17.2
	
	
! INVALID - Spaces not allowed within option field
2030  sao132680  5 54 29.5  -3 45 40  B1950  pm = -2 -19
	
! INVALID - No option label
2030  sao132680  5 54 29.5  -3 45 40  B1950  -2  -19
	
! INVALID - No index number or name
17 05 40.00  +21 36 00.00  J2000

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