primary format definition



 BAA VSS database

  data input

  primary format

  primary format example

  Excel spreadsheet

  data field definitions

  data conversion

  input software

  observer codes


This definition may seem heavy going - but don't panic: most people have managed to enter most of their data simply by referring to the example file.

This is based upon the format used by Dave McAdam. Data files in this format may be created with a simple text editor.

I am not aware of a previous formal definition of this format; I believe the closest thing to a definition was an example in a BAAVSS Circular. This is not really adequate from the point of view of someone developing database software (e.g. how long can the star name be? do all the header lines have to be in the same order?). A full definition of the primary input format is given here.

Note that items shown in yellow refer to data which are described further in Data Field Definitions.

Primary format data files are ascii files. Your data may contain the characters 0-9, a-z, A-Z, +, - ,[,],<,>, (, ), decimal point and comma. Primary format files also contain the forward slash (/) character, but this is used only as a delimiter in certain parts of the input file. You can use spaces to separate items on the input line; the number of spaces is not critical.

The first entry in a primary format file shall always be *BAAVSS*, in upper case, starting in the leftmost column. Thereafter, primary format files consists of keywords, which are followed by input data on the same line, and data sections, which contain observations for a particular star spread over a number of lines.

Keywords are case insensitive, but must start in the leftmost column. They start and with an asterisk. They are usually followed by an input data field, and the maximum length for this data field is specified below (any spaces between the second asterisk and start of the data field are ignored and do not count as part of the data field).

The keywords are as follows:

*year* is followed by the year (four digits) and sets the year for the subsequent data sections.

*loc* or *location* is followed by the observers location (coordinates) .

*name* is followed by the observer name.

*instr* or *instrument* or *instruments* is followed by a forward slash (/) and then list of instruments. There may be up to 10 instruments, of up to 20 characters each. They must be separated by forward slashes, and the instrument list must be terminated with a forward slash. You are advised to pay attention to the format of this line; it has caused problems in the past.

*star* is followed by the object name.

*chart* is followed by the chart (sequence) label.

*UT* defines the time system as UT for subsequent data.

*GMAT* defines the time system as GMAT for subsequent data.

These keywords may appear in any order, except that *GMAT* or *UT* always introduces a data section.

The original format also included *addr* which was followed by the observer's address. The address was never transferred to the database and can now be omitted from the input files.

Data sections follow the keywords *star*, *chart*, and then either *GMAT* or *UT*, in that order. Data sections consist of one or more data lines - each with one observation - and are terminated by a blank line. There should be no blank lines within a single block of data. A blank line will denote the end of the block of data, and the program will start looking for the next keyword.

Data lines contain the following:

month day / time / estimate / magnitude / class / instrument code / comment

The month must be specified on the first data line in each data section. If it is omitted from any subsequent lines, the last specified month will be assumed.