Prime Keys are:
	CarrRot
	LonHG
	LatHG
	LonCM
	MidTime
DB Index Keys are:
	CarrRot
	LonHG
	LatHG
	LonCM
All Keywords for series mdi.hmi_rdVtrack16:
	CarrRot   	(int)	Carrington rotation at MidTime
	LonHG     	(float)	Longitude of tracked region center
	LatHG     	(float)	Latitude of tracked region center
	LonCM     	(float)	CM Longitude of region center at MidTime
	MidTime   	(time)	Midpoint of tracking interval for AR
	LonSpan   	(float)	Span of tracking interval
	start     	(time)	Start of tracking interval
	stop      	(time)	End of tracking interval
	first     	(time)	ObsTime of first image used
	last      	(time)	ObsTime of last image used
	coverage  	(float)	Valid data coverage: valid / (valid + interp)
	Cadence   	(float)	Temporal image cadence
	Duration  	(int)	Length of tracking interval
	Size      	(float)	Diameter of tracked region
	Scale     	(float)	Map scale
	ZRate     	(float)	Zonal tracking rate wrt Carrington
	MRate     	(float)	Meridional tracking rate
	MapProj   	(string)	Map projection
	PosAng    	(float)	Position angle of Carrington north wrt axis 2
Segments for series mdi.hmi_rdVtrack16:
	V         	    m/s	   fits	256x256x1664	Tracked Data Cube
	Log       	     NA	generic	Tracking log