Map files

Map files are post-processed data produced from grid files. They include all the information included in the original grid file, plus the additional information related to the convection mapping. Map files are generated using a multi-step process described in the map_grid tutorial.

Naming Convention

Separate map files should be created for each hemisphere. The community standard for naming these files is:

YYYYMMDD.north.map

YYYYMMDD.south.map

Scalar Fields

Start and end times refer to the start and end of the integration period (usually 2 minutes).

Field name	Units	Data Type	Description
start.year	None	short	Start Year
start.month	None	short	Start Month number (not padded)
start.day	None	short	Start Day (not padded)
start.hour	hr	short	Start Hour
start.minute	min	short	Start Minute
start.second	s	short	Start Seconds
end.year	None	short	End Year
end.month	None	short	End Month (not padded)
end.day	None	short	End Day (not padded)
end.hour	hr	short	End Hour
end.minute	min	short	End Minute
end.second	s	short	End Seconds
map.major.revision	None	short	Major revision number of mapping routine
map.minor.revision	None	short	Minor revision number of mapping routine
source	None	string	Binary that produced this record
doping.level	None	short	Model doping level
model.wt	None	short	Model weighting
error.wt	None	short	Error weighting
IMF.flag	None	short	IMF availability flag
IMF.delay	min	short	IMF delay
IMF.Bx	nT	double	IMF Bx component
IMF.By	nT	double	IMF By component
IMF.Bz	nT	double	IMF Bz component
IMF.Vx	km/s	double	Solar wind speed, X-component, GSE
IMF.tilt	degree	double	Dipole tilt angle
IMF.Kp	None	double	Kp index number
model.angle	None	string	Statistical clock angle of B
model.level	None	string	Statistical model level
model.tilt	None	string	Calculated tilt angle
model.name	None	string	Name of the statistical model used (TS18, CS10, RG96, etc.)
hemisphere	None	short	Hemisphere flag (north=1)
noigrf	None	short	Flag for no-IGRF model present
fit.order	None	short	Order of spherical harmonic fit
latmin	None	float	Lower latitude boundary of data
chi.sqr	None	double	True chi-squared error
chi.sqr.dat	None	double	Chi-squared error for data only
rms.err	None	double	RMS error
lon.shft	degree	float	Longitudinal pole shift
lat.shft	degree	float	Latitudinal pole shift
mlt.start	hr	double	MLT at start of record
mlt.end	hr	double	MLT at end of record
mlt.av	hr	double	MLT at middle of record
pot.drop	V	double	Cross polar-cap potential drop
pot.drop.err	V	double	Cross polar-cap potential drop error
pot.max	V	double	Maximum polar-cap potential
pot.max.err	V	double	Maximum polar-cap potential error
pot.min	V	double	Minimum polar-cap potential
pot.min.err	V	double	Minimum polar-cap potential error

Vector fields

In the table below, the following values describe the dimensionality of the map file fields:

• numstid: the number of radars included in that grid record
• numv: the total number of gridded velocity vectors
• numft: the number of values used in the spherical harmonic analysis
• nummd: the number of vectors output by the statistical convection model
• numbd: the number of points in the Heppner-Maynard boundary

A map file will not necessarily contain a complete set of all the variables listed below. The processing is divided into stages and new fields are added to the file as appropriate. For example, the boundary.mlat and boundary.mlon fields are added by map_addhmb, and the model.mlat, model.mlon, model.kvect, and model.vel.median are added by map_addmodel.

Field name	Units	Dimensionality	Data Type	Description
stid	None	[numstid]	short	A list of numeric station IDs that provided data for the record
channel	None	[numstid]	short	A list of channel numbers associated with the station id
nvec	None	[numstid]	short	Number of velocity vectors for each station
freq	kHz	[numstid]	float	Transmitted frequency for each radar
major.revision	None	[numstid]	short	Major make_grid version number
minor.revision	None	[numstid]	short	Minor make_grid version number
program.id	None	[numstid]	short	Control program ID
noise.mean	None	[numstid]	float	Mean noise
noise.sd	None	[numstid]	float	Noise Standard deviation
gsct	None	[numstid]	short	Groundscatter flag
v.min	m/s	[numstid]	float	Minimum velocity threshold
v.max	m/s	[numstid]	float	Maximum velocity threshold
p.min	None	[numstid]	float	Minimum power threshold
p.max	None	[numstid]	float	Maximum power threshold
w.min	m/s	[numstid]	float	Minimum spectral width threshold
w.max	m/s	[numstid]	float	Maximum spectral width threshold
ve.min	m/s	[numstid]	float	Velocity error minimum threshold
ve.max	m/s	[numstid]	float	Velocity error maximum threshold
vector.mlat	degrees	[numv]	float	Magnetic Latitude
vector.mlon	degrees	[numv]	float	Magnetic Longitude
vector.kvect	degrees	[numv]	float	Magnetic Azimuth
vector.stid	None	[numv]	short	Station identifier
vector.channel	None	[numv]	short	Channel number
vector.index	None	[numv]	int	Grid cell index
vector.vel.median	m/s	[numv]	float	Weighted mean velocity magnitude
vector.vel.sd	m/s	[numv]	float	Velocity standard deviation
vector.pwr.median	dB	[numv]	float	Weighted mean power
vector.pwr.sd	dB	[numv]	float	Power standard deviation
vector.wdt.median	m/s	[numv]	float	Weighted mean spectral width
*vector.wdt.sd	m/s	[numv]	float	Standard deviation of spectral width
N	None	[numft]	double	L value of the expansion between 0 and Lmax
N+1	None	[numft]	double	M value of the expansion between -L and +L, negative values indicating the sin(M*phi) term
N+2	None	[numft]	double	Value of the coefficient
N+3	None	[numft]	double	Estimate of the 1-sigma error of the coefficient
model.mlat	degrees	[nummd]	float	Magnetic Latitudes of the model vectors
model.mlon	degrees	[nummd]	float	Magnetic Longitudes of the model vectors
model.kvect	degrees	[nummd]	float	Magnetic Azimuths of the model vectors
model.vel.median	m/s	[nummd]	float	Velocity medians of the model vectors
boundary.mlat	degrees	[numbd]	float	Magnetic Latitudes of the lower latitude boundary
boundary.mlon	degrees	[numbd]	float	Magnetic Longitudes of the lower latitude boundary