The data catalogue is a file of telescope control information which may be accessed through the display sequence. It resides on disc and consists of a series of named records. Each record typically consists of a star position but may contain other types of data - the parameters for raster scan, for example.
Creation from a file is the preferred method, allowing the catalogue to be created afresh if it has been destroyed or altered. Normally observers will create their data file on one of the VAX computers and the night assistant will transfer it to the telescope computer.
Lines of data in the file are referred to as cards in the AAO Technical Manual 7 - The Telescope Control System - for historical reasons. This protocol is retained here. A sample data file is given below, and can be used as a template. Normally only mean place records (those with an M as the first character) will be needed. A single line may form a complete record - a mean place, typically - or a record may be built up from several lines - a mean place, a raster scan, and a focus demand, for example.
Blank lines and comment lines (beginning with ` *') may be placed among the file to clarify the listing produced when the catalogue is created.
Each data record has four fields which must occur in the order shown:-
Each field may be preceded and followed by spaces; at least one space must be left between the data type and the name.
The DATA-TYPE must be one of the following:-
M mean place A apparent place R raster scan F telescope focus O position offset P rotator position angle D differential tracking rates
Only the first character of the data type matters, and any non-blank characters following the data type are ignored - `MEAN' will be read (correctly) as `M' for example.
The NAME consists of ten characters, including embedded and trailing spaces.
On the first - and usually the only - line of each record, the name is punched in full. On subsequent lines, if any, a single `ditto' symbol must be punched ("). All `ditto' items are assigned to the record name most recently preceding them.
Take care to avoid duplicating one data type under one record name, and do not duplicate a record name; no checks are made when the catalogue is created.
The structure of the DATA field depends on the data type, and will be described in detail later. It follows the same format as the data entry displays, including units and allowed ranges. However, a great deal of freedom is allowed in the way the individual numbers are expressed, and any reasonable format is acceptable providing all mandatory fields are present and in the order shown. The example deck given later contains a variety of formats, all of which are acceptable.
The NOTES field is optional. It is wise to begin each note with ` *' to avoid errors in the rare cases where a note could be confused with an optional data field.
Notes are transferred to the catalogue along with the data, and will appear on listings of the catalogue made using the program FILIST. However, if a record is updated from the keyboard, the notes are lost. Notes cannot be examined through the display sequence.
MEAN PLACE - data type M
9 items; the last 2 may be omitted, but only together.
And the optional:-
APPARENT PLACE - data type A
6 items; all must be present.
RASTER SCAN - data type R
5 items; all must be present.
TELESCOPE FOCUS - data type F
TELESCOPE POSITION OFFSET - data type O
2 items; 1 must be present.
ROTATOR POSITION ANGLE - data type P
DIFFERENTIAL TRACKING RATES - data type D
2 items; the second may be omitted if zero.
Below is an example input file. The deck is highly atypical; in practice, a FILE deck consists almost entirely of mean places.
START OF DEMONSTRATION DECK
M STAR 25 20 15 27.1 -63 4 20 1950.0 * STANDARD 13.8 MAG
M 73 NE 4 18 3.6 -50 4 56 1975 RADIO POSITION
A STAR B 11 54 17 25 16 10
* SERIES 24
M GXY 1 11 12 13.4 -32 12 18 1950
O " E14 S20.3 OFFSETS FROM SCHMIDT PLATE TO 0.2MM
M GXY 2 12 2 33.5 -32 02 11 1950.0
O " E 18.5 N107
M GXY 2A 12 2 13.4 -32 41 42 1950
O " W 3.5 N8.2 SUPERNOVA?
* HII REGION
M REGION 7.1 12 00 14 +14 27 30 1975
R " 850.00 300.00 19 15 90 6 ARCSEC/SEC
M SAO 232973 03 01 27.23 -58 02 42.1 1950.0 +0.0045 -0.026 MV=10
A STAR 28 12 4 16.3 -24 00 59
R EXPT 3 660 180 11 12.0 180.0 3X2 ARCMIN IN 11 MIN
F F2 73.91 SHIFTED LAMBDA/4 INWARDS
O GALAXY17 E 17.31 S 104 BASE STAR SAO 201704
P INS 1 120
D COMET FRED +118.24 -327.6 1976 APRIL 7
A START 1 3 4 19.3 -0 0 10 * OBSERVATION 1
F " 71.3
P " 90
F KE 73.05 KNIFE EDGE
F INST 60.99 (NO FILTER)
F TV 72.83 CAMERA AT HOLE 3
F DONUT 70 DOUGHNUT IMAGE, 1.5MM AT F/15
M PALLAS 6 33 56.78 -5 14 49.4 1950 * 1976 AUGUST 21 8H UT
D " 293.04 -1126.8
END OF DEMONSTRATION DECK
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Exposure times OFFSET_RUN files CCD Windows Data Catalogs
On-line Reduction Filters Flat-fields Blank Fields Orientation Shutters
This Page last updated: 8 Mar 1996, by Chris Tinney
START OF DEMONSTRATION DECK