clemnircal
Performs radiometric corrections on Clementine NIR images
This program performs radiometric corrections to images acquired by the Clementine spacecraft Near Infrared camera and writes the output image values in units of radiance.
EQUATIONS
Term1 = ( DR(x,y) - digital_offset ) / Gfact(gm)
Term2 = Term1 - bias_global - BIAS(x,y) - (om * V)
Term3 = Term2 / t
Term4 = Term3 - DC(x,y) - 0.730
Term5 = Term4 - therm - thermShape
Term6 = Term5 / FF(x,y)
Term7 = Term6 / OF(x,y)
Term8 = Term7 - AF(x,y)
R(x,y) = Term8 * abscoef
General equations applied to data for radiometric correction are indicated below:
Let: x,y = line and sample position of pixel in an image
R(x,y) = Result of correction in absolute radiance.
DO(x,y) = Result of correction. The output can either be absolute radiance values or they can be converted to reflectance(I/F values
DR(x,y) = Raw input density number
FF(x,y) = Flat-field as a function of filter and line, sample
position. This will be read from an ISIS cube file.
OF(x,y) = Orbit dependent flat file correction.
DC(x,y) = Dark current as a function of compression type,
line, sample position. AF(x,y) = Empirical additive flat-field coefficients at line, sample position.
BIAS(x,y) = Bias correction as a function of compression type, line, sample position.
digital_offset = 9.0
bias_global = 2.0
V = -.91
abscoef = 1.0
g(GainModeID) = Gain factor as a function of insturment GainModeID
g(0) = 2.0235
g(1) = 8.2755
g(2) = 4.9144
g(5) = 0.9443
g(8) = 4.1835
g(9) = 1.3530
g(11) = 15.9844
g(13) = 7.77177
g(16) = 28.1618
g(17) = 24.8658
g(18) = 21.9100
g(19) = 18.6140
g(22) = 6.83130
g(23) = 3.48425
g(24) = 20.3218
g(25) = 17.9433
g(26) = 15.8104
g(27) = 13.4320
g(28) = 9.32361
g(29) = 6.95951
g(30) = 4.75472
g(31) = 2.43896
g(33) = 13.9238
g(34) = 12.2687
g(36) = 7.23501
g(41) = 7.04438
g(42) = 6.16495
g(44) = 3.57405
g(45) = 2.73995
g(46) = 1.88595
g(48) = 11.9078
g(50) = 9.26433
g(52) = 5.39513
g(53) = 4.08125
g(61) = 1.40899
g(62) = 0.964975
gm = Gain_mode of instrument(gm = 1,2,4)
om = Offset_mode of instrument(om = 1,2,3,4,...,31)
t = Optimal integration duration of observation in seconds (function of ExposureDuration on labels in milliseconds.)
therm = Thermal background correction value
thermShape = Thermal shape correction value (always 0.0)
Categories
Related Objects and Documents
Applications
History
Tracie Sucharski | 1994-11-28 | Original Version (nircal.F) |
Steven Lambright & Steven Koechle | 2007-05-16 | Converted to Isis 3.0 |
Steven Koechle | 2007-06-11 | Removed unused Thermal Shape Correction Parameter. Fixed table lookup problem, and Radiometry group |
Steven Lambright | 2007-06-14 | Fixed bugs in XML file, added an example, added more data to Radiometry group. |
Christopher Austin | 2007-02-20 | Altered the output cube's BandBin group, changing the Keyword "Name" back to "FilterName". |
Steven Lambright | 2008-05-13 | Removed references to CubeInfo |
Parameters
Files
Type | cube |
---|---|
File Mode | input |
Filter | *.cub |
Type | cube |
---|---|
File Mode | output |
Pixel Type | real |
Filter | *.cub |
Type | cube |
---|---|
File Mode | input |
Internal Default | Automatic |
Filter | *.cub |
Type | cube |
---|---|
File Mode | input |
Internal Default | Automatic |
Filter | *.cub |
Type | cube |
---|---|
File Mode | input |
Internal Default | Automatic |
Filter | *.cub |
Type | cube |
---|---|
File Mode | input |
Internal Default | Automatic |
Filter | *.cub |
Type | cube |
---|---|
File Mode | input |
Internal Default | Automatic |
Filter | *.cub |
Type | cube |
---|---|
File Mode | input |
Internal Default | Automatic |
Filter | *.cub |
Settings
Type | boolean |
---|---|
Default | true |
Type | boolean |
---|---|
Default | true |
Type | double |
---|---|
Default | 1.0 |
Type | double |
---|---|
Default | 240.0 |
Example 1
Calibrating a cube to radiance values using nircal
Command Line
clemnircal
nircal FROM=lna3056k.cub TO=lna3056k.cal.cub
GUI Screenshot
Calibrate lna3056k.cub
Calibrate clemnircal.cubIn this example clemnircal will calibrate lna3056k.cub using the defaults.
Input Image
Image before correction
lna3056k.cub before being corrected
Parameter Name:
FROM
This is the input image lna3056k.cub before being corrected with clemnircal.