A method has been implemented to summarize the qualities of MDI data. The keyword QUALITY is set for each image or data element. If bits are set in QUALITY there may be something noteworthy or bad in the data. QUALITY bits are determined using both automatic criteria and by manual inspection. Automatically determined indicator bits are first set in the data status word, DATA_SW (e.g. the fraction of missing). Those set subjectively are contained in the keyword PROBLEM. These are combined to determine QUALITY.

This page is intended to summarize how these keywords are to be used and understood.

These keywords appear at level 1 and higher.

The DEFINITIVE values are in the level 1 log files.
Derivative values appear in the higher level log files, the record files at higher levels, in the mission long summary binlogs, and in various Data_Good files. Each quantity is actually described by 3 keywords indicating the value, the validity, and the time it was set:

Order of Quality Propagation

General Properties of QUALITY, DATA_SW and PROBLEM

Quality Bit Assignments

Common bits

Context Specific Bits

For programming usage, appropriate #DEFINEs for the bits can be found in ~CM/include/data_qual.h This should be updated as new definitions are created.

DATA_SW - the Automatically Determined Data Status Word

The DATA_SW keyword contains bitwise information derived during data processing.

PROBLEM - Manually Determined Properties of the Data

QUALITY - Summary of the Qualities of an Image

When deciding whether to use data, the bits of QUALITY must be evaluated. For convenience a mission-long fits file containing QUALITY and QUAL_VLD will be created for each data series that can be exported along with a data set. Anyone can then specify a way to evaluate the various bits to make a selection. The program binlog_upd will update these files.

BINLOGs and Data_Good files

BINLOGs and Data_Good files collect QUALITY information into a more compact and useable form.


QUALITY and QUAL_VLD are collected in on-line mission-long log files called BINLOGs.
There are two classes of binlogs: Observable and Data Series BINLOGs.
Binlogs are fits files.


The Data_Good stuff is not very well defined yet.


The responsibilty to oversee data quality has been divided. Each responsible scientist is listed below, together with the data products he will examine on an ongoing basis.

Rick Bogart

Rock Bush

Tom Duvall

Todd Hoeksema

Phil Scherrer

Jesper Schou

Some Historical Notes
Author JTH; Last modified by rsb 26 Jan, 2000