make printable	new:	See also :
	version 1.0	- the tool is distributed through the utilities package (utilPack) - hideFrame: the tool to request header updates databases SAFIQ dfos tools   output used by ngasClient upload/download download: headers from SAFIQ

hotfly

Description

hotfly = headers on the fly: this is a tool for

• downloading headers., or
• modifying headers of downloaded fits files.

The source of information is the keyword repository (also called "SAFIQ"* or the "warehouse"). This repository stores all header keywords, including the ones from extensions. Technically, it is an "inverted" database table where all keywords are essentially stored as "name - value" pairs (very much like in the original headers), in contrast to a traditional databasetable where a complete header would be stored as one record (one line) with as many columns as keywords. This different architecture makes it possible to store, address, and update each single name-value pair. This is impossible in a traditional table like dp_products (where only standard keys like arcfile and dp_catg are stored) or dp_headers (where only the header name and its complete, "frozen" content are stored and cannot be updated).
*(where nobody at ESO can tell what IQ stands for ...) More about Sybase IQ e.g. here ...

Any change of a header keyword which has been done in SAFIQ is reflected in a header downloaded with hotfly, or in a fits file header updated with hotfly. In particular, any change of a raw file header key which you have requested from dbcm using hideFrame will be reflected.

Currently the insertion of new headers in SAFIQ takes place roughly every 24 hours. This means that currently no header younger than about a day can be downloaded or updated.

Extensions. By default the tool downloads and updates the complete header, including all extensions if existing. You may want to focus on the primary header only, using the option -p. After all, all information required for OCA should be in the primary header.

Comparison of all current header download mechanisms

* difference between 'now' and last header available
**download per hdr on old system
1+2: first method 1 (for preview, corrections etc.), then method 2 (upon processing): combines all advantages

Combining methods 1 and 2 currently offers all advantages. This means that for all dfos applications requiring up-to-date headers (qc1Parser and the future calChecker) we continue to use dataclient -t h. For processing with autoDaily (creating ABs and downloading on demand) the preferred method is ngasClient with hotfly (ngasClient -f).

Setup

In the .dbrc file you should have access to the SAFIQ server. Add this line to the .dbrc file:

SAFIQ QC <passwd> HOTFLY_OP

where <passwd> is the password for the QC user, and HOTFLY_OP is an alias for the operational server.

Make sure that your .qcrc also includes the line

export HOTFLY_DBALIAS=HOTFLY_OP

and that you source the modified .qcrc before using hotfly or the updated ngasClient.

How to use

Usually you will not run the tool on the command line, but within ngasClient. Command-line usage:

Type hotfly -h for on-line help, hotfly -v for the version number.

To download a header, use

hotfly -H AMBER.2007-11-21T20:34:21.626.hdr ;

to update the header of an existing fits file (you need to be in the directory where the fits file is located):

hotfly -f AMBER.2007-11-21T20:34:21.626.fits ;

to have the primary header updated only, type

hotfly -f AMBER.2007-11-21T20:34:21.626.fits -p .

Installation

The tool comes as part of the utilPack delivery.

Configuration file

none.

Operational aspects

• Note that the order of keys and the format of the header may slightly differ from the original one.