clemhirescal

This program serves to calibrate most images from the Clementine Hires camera. It does so through the use of some constants based on offset and flat images based on filter type. There are six possible offsets, with the resultant change being anywhere between eight and fifty to the DN. There are four flat images, one for each of the four possible filters. Information for this program came from JGR Vol 108, A radiometric calibration for the Clementine Hires camera: Robinson, Malaret, White. The original paper can be found at https://doi.org/10.1029/2000JE001241 The equation for the A filter yields k values that are identical to those in Table 5 from Robinson et al. (2003), therefore the pixel values in the output image are the same as they would be if the k values from Table 5 were hard coded into the script. The equation for the D filter yields k values that differ from the hard-coded values by less than 1 standard deviation as reported in Table 6 of Robinson et al. (2003). The radiance values that result from the computed k values differ by no more than .0583% of the radiance values computed from the k values published in Table 6.

Description

Use this parameter to select the filename

Type	cube
File Mode	input
Filter	*.cub

Description

This file will contain the results of the calibration

Type	cube
File Mode	output
Pixel Type	real
Filter	*.cub

Description

This parameter is used to choose either a user entered K value or a previously set, calculated K value.

Type	string
Default	COMPUTED
Option List:	Option Brief Description COMPUTED Compute a K value from MCP gain mode This option has the program use a known K value depending on the MCP gain and filter type, very few MCP gain mode IDs are supported. The K value is the absolute coefficient per wavelength and MCP gain state. Exclusions KVALUE USER User input K value User chooses a K value and enters it into the system. This is more likely as very few MCP gain modes are supported. Inclusions KVALUE

Description

The K value is the absolute coefficient per wavelength and MCP gain state. This is an average of several possible K values, the default should not be used when possible as it is an average.

Type	double
Default	0.00125
Minimum	0.0 (exclusive)
Maximum	0.05 (exclusive)

This shows the usage of the clementine high resolution image calibration program. In this case a K value can be computed for the image.

clemhirescal from= clem2.cub to=clem2CAL.cub

clemhirescal gui

Example GUI Screenshot of the GUI with parameters set to calibrate a hires image using a perviously set K value.

The image before the calibration

Input image before calibration Parameter Name: FROM This is the image as it was taken originally, complete with hotspot and chickenwire pattern.

Flat file denominator	This is one of the four avaliable flat files. It is the one used on the image you see, it is specifically for the D filter type.

The image after the calibration

Output image after calibration Parameter Name: TO The image should now appear more even, without hotspot or chickenwire pattern, and radiometrically calibrated.