iqdat DataMap variables definitions

RFC: 0027

Title

iqdat DataMap variables definitions

Author

R.J.Barnes

Summary

A description of the variables stored in a iqdat DataMap file.

Description

1. Introduction

The iqdat files are stored using the DataMap self-describing file format. Listed here are the variable names and definitions.

2. Scalars

The scalar components of the iqdat file format are listed below:

Variable Name	Data Type	Description
radar.revision.major	char	Major version number of the radar operating system.
radar.revision.minor	char	Minor version number of the radar operating system.
origin.code	char	Code indicating origin of the data.
origin.time	string	ASCII representation of when the data was generated.
origin.command	string	The command line or control program used to generate the data.
cp	short	Control program identifier.
stid	short	Station identifier.
time.yr	short	Year.
time.mo	short	Month.
time.dy	short	Day.
time.hr	short	Hour.
time.mt	short	Minute.
time.sc	short	Second.
time.us	short	Micro-Second.
txpow	short	Transmitted power (kW).
nave	short	Number of pulse sequences transmitted.
atten	short	Attenuation level.
lagfr	short	Lag to first range (microseconds).
smsep	short	Sample separation (microseconds).
ercod	short	Error code.
stat.agc	short	AGC status word.
stat.lopwr	short	LOPWR status word.
noise.search	float	Calculated noise from clear frequency search.
noise.mean	float	Average noise across frequency band.
channel	short	Channel number for a stereo radar (zero for all others).
bmnum	short	Beam number.
bmazm	float	Beam azimuth.
scan	short	Scan flag.
offset	short	Offset between channels for a stereo radar (zero for all others).
rxrise	short	Receiver rise time (microseconds).
intt.sc	short	Whole number of seconds of integration time.
intt.us	short	Fractional number of microseconds of integration time.
txpl	short	Transmit pulse length (microseconds).
mpinc	short	Multi-pulse increment (microseconds).
mppul	short	Number of pulses in sequence.
mplgs	short	Number of lags in sequence.
nrang	short	Number of ranges.
frang	short	Distance to first range (kilometers).
rsep	short	Range separation (kilometers).
xcf	short	XCF flag.
tfreq	short	Transmitted frequency.
mxpwr	int	Maximum power (kHz).
lvmax	int	Maximum noise level allowed.
iqdata.revision.major	int	Major version number of the iqdata library.
iqdata.revision.minor	int	Minor version number of the iqdata library.
combf	string	Comment buffer.
seqnum	int	Number of pulse sequences transmitted.
chnnum	int	Number of channels sampled (both I and Q quadrature samples).
smpnum	int	Number of samples taken per sequence.
skpnum	int	Number of samples to skip before the first valid sample.

2. Arrays

The Array components of the iqdat file format are listed below:

Variable Name	Data Type	Dimensions	Description
ptab[mppul]	short	mppul	Pulse table.
ltab[2][mplgs]	short	2,mplgs	Lag table.
tsc[seqnum]	int	seqnum	Seconds component of time past epoch of pulse sequence.
tus[seqnum]	int	seqnum	Microsecond component of time past epoch of pulse sequence.
tatten[seqnum]	short	seqnum	Attenuator setting for each pulse sequence.
tnoise[seqnum]	float	seqnum	Noise value for each pulse sequence.
toff[seqnum]	int	seqnum	Offset into the sample buffer for each pulse sequence.
tsze[seqnum]	int	seqnum	Number of words stored for this pulse sequence.
data[totnum]	int	totnum	Array of raw I and Q samples.

The extent of each dimension is determined by the radar operating parameters. For example a value of mppul of 7 would result in the array ptab[7].

The raw sample data is arranged in multiplexed I and Q sample order; so the first smpnum*2 samples are the interleaved I and Q values for the first pulse sequence. If more than one channel is samples, the next smpnum*2 samples represent the next channel. The total number of samples,totnum, is equal to 2*seqnum*chnnum*smpnum.

References

RFC #0006

History

2008/03/25 Initial Revision.