dimensions:
	longitude = 23 ;
	latitude = 17 ;
	nGridPoints = 391 ;
	epoch = UNLIMITED ; // (2880 currently)
	length = 8 ;
	length2 = 4 ;
	nSatellites = 35 ;
	nStations = 209 ;
variables:
	char epoch(epoch, length) ;
		epoch:units = "hours:minutes:seconds" ;
		epoch:title = "Epoch of each VTEC map" ;
	float longitude(longitude) ;
		longitude:units = "degrees" ;
		longitude:title = "Grid point longitudes" ;
	float latitude(latitude) ;
		latitude:units = "degrees" ;
		latitude:title = "Grid point latitudes" ;
	short satellite(nSatellites) ;
		satellite:title = "Satellite ID list" ;
	char station(nStations, length2) ;
		station:title = "Station list" ;
	byte observations(epoch, nStations, nSatellites) ;
		observations:title = "Matrix of stations/satellites used" ;
	float vtec(epoch, latitude, longitude) ;
		vtec:units = "TECU" ;
		vtec:title = "Estimated VTEC at the grid points" ;
	float sigma(epoch, latitude, longitude) ;
		sigma:units = "TECU" ;
		sigma:title = "Errors on the estimated VTEC" ;

// global attributes:
		:algorithm_version = "v1.0      " ;
		:reference_station = "wtzr" ;
		:ionosphere_altitude (m) = 350000.f ;