[gradsusr] MODIS CLOUD TOP TEMPERATURE

[Joshua Ngaina]

Dear All,

I am extracting cloud top temperature  from MODIS satellite. I have
written a descriptor file as shown below.
DSET  ^mod%d2.nc
TITLE Aerosol Optical Depth
OPTIONS template
UNDEF -9999
XDEF 360 LINEAR 0.0 1
YDEF 180 LINEAR -89.5 1
zdef 1 linear 0 1
TDEF 14 LINEAR 0Z10jan2001 1dy
VARS      1
cloud_top_tempe 0 y,x Cloud Top Temperature: Mean
ENDVARS

Checking control file information, the TDEF seems different
ga-> q ctlinfo
dset mod%d2.nc
title Aerosol Optical Depth
undef -9999
xdef 360 linear 0 1
ydef 180 linear -89.5 1
zdef 1 linear 0 1
tdef 14 linear 00Z10JAN2001 1440mn
vars 1
cloud_top_tempe  0  y,x  Cloud Top Temperature: Mean
endvars

The attributes of my file is as shown
ga-> q attr
No Descriptor Attributes for File 1 :

Native Attributes for File 1 :
global String Conventions CF-1.0
lat Int32 scale 0
lat Float32 stride 1
lat String gridReference edge
lat String standard_name latitude
lat Float32 endValue 90
lat String units degrees_north
lat String scaleType linear
lat Float32 startValue -90
lat Int32 size 180
lon Int32 scale 0
lon Float32 stride 1
lon String gridReference edge
lon String standard_name longitude
lon Float32 endValue 180
lon String units degrees_east
lon String scaleType linear
lon Float32 startValue -180
lon Int32 size 360
cloud_top_tempe Float32 _FillValue -9999
cloud_top_tempe String Quality_Assurance_Data_Set None
cloud_top_tempe Float32 scale_factor 1
cloud_top_tempe Float32 add_offset 0
cloud_top_tempe String long_name Cloud Top Temperature: Mean
cloud_top_tempe String Statistic_Type Simple
cloud_top_tempe String units Degree
cloud_top_tempe String Aggregation_Data_Set None
cloud_top_tempe Int32 valid_range 0,20000
cloud_top_tempe String Included_Level_2_Nighttime_Data True
cloud_top_tempe String Derived_From_Level_2_Data_Set Cloud_Top_Temperature
cloud_top_tempe String Level_2_Pixel_Values_Read_As Real
cloud_top_tempe String structureType Grid
cloud_top_tempe String unitsCategory temperature

However, the values I get from a point are as shown. Note that some of
these values are quite extreme.
-1.29021e-23
-6.92459e+32
33170.3
1.98182e+11
2.08584e-26
-5.06712e+26
3.17729e+23
-2.23413e-29
0.0676561
2.40895e-26
-8.06725e-36
5.39458e+17
-1.05303e-10
57747.3

Can anyone help me point out the error ?