Table of Contents
netCDF Required Dimensions
netCDF Variable Names
netCDF Variable Attributes
netCDF Global Attributes
Diagnosing Access Problems
Example of ncdump
Dimension | Description | Required by GFESuite? |
x | X-dimension of the satellite image |
Yes |
y | Y-dimension of thje |
Yes |
Variable Name |
Data Type | Dimensions | Description | Required by GFESuite? |
image |
2-D array of bytes |
(y,x) | Contains the satellite data, ranged from 0-255 (might be seen
as -127 to +127) |
Yes |
Attribute | Description | Required by GFESuite? |
projName | Contains the projection name. Must be one of the following: LAMBERT_CONFORMAL, MERCATOR, STEREOGRAPHIC, LATLON, CYLINDRICAL_EQUIDISTANT | Yes |
lon00 | Longitude in degrees of lower-left grid point (0, 0) | Yes |
lat00 | Latitude in degrees of lower-left grid point (0, 0) | Yes |
latNxNy | Latitude in degrees of upper-right grid point (maxX, maxY) | Yes |
lonNxNy | Longitude in degrees of upper-right grid point (maxX, maxY) | Yes |
centralLon | Center longitude for the mercator projection, where the mercator projection is parallel to the Earth's surface. Center longitude for the polar stereographic and Lambert Conformal projections, where the projection has north as straight up. | Yes |
centralLat | Center latitude for the polar stereographic and Lambert Conformal projections, where the plane intersects the Earth's surface. | Yes |
This is an example ncdump from a water vapor D2D file; each directory
contains one band (wavelength), each file contains one image:
netcdf 20031112_2130 {
dimensions:
y = 640 ;
x = 550 ;
variables:
byte image(y, x) ;
double validTime ;
validTime:units = "seconds since 1970-1-1 00:00:00.00 0:00" ;
validTime:long_name = "Valid Time" ;
byte valid100thSecs ;
valid100thSecs:units = "centiseconds" ;
valid100thSecs:long_name = "Valid 100th of a second" ;
// global attributes:
:channel = "6.7 micron" ;
:depictorName = "westConus@17659725" ;
:projIndex = 3 ;
:projName = "LAMBERT_CONFORMAL" ;
:centralLat = 25.f ;
:centralLon = -95.f ;
:rotation = 25.f ;
:xMin = -0.2556496f ;
:xMax = 0.01474848f ;
:yMin = -0.8768771f ;
:yMax = -0.5622397f ;
:lat00 = 54.53548f ;
:lon00 = -152.8565f ;
:latNxNy = 17.51429f ;
:lonNxNy = -92.71996f ;
:dxKm = 7.871384f ;
:dyKm = 7.869175f ;
:latDxDy = 39.25658f ;
:lonDxDy = -117.4858f ;
}
data:
image =
0, -70, -70, -71, -70,
-70, -70, -70, -71, -71, -71, -70, -70,
-70, -69,
-70, -71, -70,
-70, -71, -71, -71, -71, -70, -69,
-70, -71, -71, -72,
-71, -71, -71,
-71, -72, -72, -71, -71, -71, -72,
-72, -71, -71, -70,
-71, -72, -72,
-72, -73, -73, -72, -72, -71, -70,
-71, -71, -71, -70,
-70, -70, -69,
-69, -69, -69, -69, -69, -69, -69,
-69, -69, -69, -69,
-68, -68, -67,
-69, -69, -68, -68, -67, -67, -67,
-67, -67, -67, -67,
-67, -66, -66,
-67, -67, -67, -68, -68, -68, -68,
-68, -68, -68, -68,
-68, -68, -68,
-68, -68, -68, -68, -68, -68, -67,
-67, -66, -67, -66,
-65, -64, -64,
-63, -63, -62, -63, -62, -60, -61,
-61, -61, -61, -61,
-60, -61, -61,
-61, -61, -61, -60, -61, -61, -60,
-61, -62, -61, -60,
-60, -60, -60,
-60, -60, -59, -60, -61, -61, -61,
-60, -60, -60, -60,
-60, -59, -59,
-59, -59, -58, -58, -58, -59, -58,
-58, -57, -56, -57,
-57, -57, -57,
-56, -56, -56, -55, -55, -55, -55,
-55, -55, -55, -56,
-55, -55, -56,
-56, -56, -56, -57, -57, -57, -57,
-58, -58, -59, -59,
-59, -59, -59,
-60, -60, -61, -61, -61, -61, -61,
-61, -61, -61, -61,