Grammar for .scd files

1990/12/14 T.Handa
1992/2/13 T.Handa
1996/12/21 T.Handa
translate in English 1997/6/14 T.Handa
1997/6/24 T.Handa

* Remarks : In Japanese character set \ (back slash) is replaced by \ (Yen mark). These two characters shared the same binary code and no difference for DOS system. In other word DOS system cannot recognize the difference of these two characters. You should read \ for \ if you find it on screen or writing.

This manual is written based upon the onoff command version 2.60 and later and corresponding other commands. Older systems may not support some of the following functions. See a:\obs\readme.doc in your PC about the latest version.

Basic structure of a file

ASTROS interprets one line as a basic unit. One line defines by 256 or less characters in ASCII code and the last two characters are CR and LF.
Every line in the .scd file must be one of the following five categories; a comment line, a region definition line, a frequency setup line, an integration instruction line, and an end line.
A comment line can be written at any position in a file. A region description line must be the first line in a file except for comment lines. A frequency setup line must be the second line in a file except for comment lines. An end line should be the last line of a file because ASTROS do nothing after the end line. Integration instruction lines must be after the frequency setup line and before the end line.
In every line any characters after "/*" are interpreted as a comment. Parameters which must be select from the listed items showing below are case insensitive.

A Comment Line

A comment line can be written at any position in a file. The comment lines affect nothing for the system. The first character of the comment line must be "#", "/", or "\".

example

	# This is a comment line.

A Region Description Line

A region description line must be the first line in a file if all comment lines are removed. Only one region description line is required in the .scd file. It describes information about region on sky which should not be changed during an observing session.
The region description line requires two or three or five parameters which are separated by ";" or "\" or tab. In this line the parameters are not separated by " " (blank space).
The first parameter is for the project name. The name must be shorter than 16 characters.
The second parameter is for object or region name. The name must be shorter than 15 characters.
The third parameter is for first execution line but fixed to 1 at present. The fourth and fifth parameters are for the range (minimum and maximum values) of the quick look display on ASTROS screen in K.

example

	Galactic survey;Carina;1;-5.5;10

A Frequency Setup Line

A frequency setup line must be the second line in a file if all comment lines are removed, and after the region description line. Only one frequency setup line is required in the .scd file. It describes information about frequency setup which should not be changed during an observing session.
The frequency setup line requires four parameters which are separated by "," (comma) or " " (blank space) or tab.
The first parameter is for the name of transition. The name must be shorter than 15 characters. The second parameter is for the value of the rest frequency of observations in GHz.
The third parameter is for the value of the first IF frequency in GHz. The fourth parameter is for the signal sideband. USB or LSB. This parameter is case insensitive.

example

	CO(J=2-1),230.5308001,4.0,usb

An Integration Instruction Line

Integration instruction lines must be after the frequency setup line and before the end line. It describes instruction for configuration and position of the telescope system.
The integration instruction line requires one to five parameters which are separated by "," (comma) or " " (blank space) or tab, although you can omit some of them if you want to keep the parameters as before.
The first parameter is for the configuration of the system. You must select one of the following. This parameter is always required. The parameter is case insensitive.

"R" or "HOT": measure the hot load.
"COLD": measure the cold load.
"ON" or "OBJ": measure the signal from an object.
"ON2": measure the signal from an object and save data using previous "OFF".
"OFF" or "SKY": measure the signal from blank sky. Data are saved when unsaved previous "ON" data are left.
"Z0": measure the response for zero input.
"END": stop observations

The second parameter is for coordinate system for the object. The parameter is case insensitive. The list of the positions are also assigned here.

"RADEC": the equatorial coordinate with the epoch B1950.0 and mean position.
"LB": the galactic coordinate (lII, bII).
"RADEC-APPARENT" or "RADEC-APP": the equatorial coordinate in present epoch and apparent position
"AZEL": the ground coordinate
"LIST" or "FILE": Position is given in a file.
"OFFSET": an ad hoc position offset in Az-El coordinate.
"*": the same as before.

The third parameter is for longitude. It must be written in the ASTROS standard angle format. Only if the longitude in the equatorial coordinates, it may be written in the ASTROS standard time format. An "*" (asterisk) or omitting the parameter itself means the same as before. If the second (coordinate) parameter is "LIST" or "FILE", you should give the name of the file with its extension, here.
The fourth parameter is for latitude. It must be written in the ASTROS standard angle format. An "*" (asterisk) or omitting the parameter itself means the same as before. If the second parameter is "LIST" or "FILE", skip this parameter.
The fifth parameter is for tracking velocity in km/s with respect to LSR. Positive value means red shifted. The system calculate only in the first order of Df/f (frequency ratio). An "*" (asterisk) or omitting the parameter itself means the same as before.
The sixth parameter is for the name of object but only valid for pointing measurement commands (opint and cpint). The name must be shorter than 15 characters. Only the separator between the fifth and sixth parameters must be tab.
If some parateters example

	on,lb,121.123d,-1d,-20
	off,list,offlst.scp,150.0

An End Line

An end line should be the last line of a file. ASTROS do nothing after the end line. The end line has only one parameter which is fixed as "end". The character "end" is case insensitive.