LLNL's Laboratory Data

Test of UVVIS sensor linearity using LLNL's Laboratory Data

This page was put together to support the validation of the UVVIS calibration procedures between ACT and remote members of the Clementine Calibration Team.

ACT received during the week of April 20th 1996 an 8mm tape from USGS with LLNL's laboratory data for the UVVIS camera. The data is in PDS format!.

Using the laboratory image data a summary file was constructed by ACT which compiles all the following camear information

filter center wavelength
target type
camera gain id
offset id
tint - integration time
FPA Temperature
Target Radiance
Chamber Temperature
Subimage mean reported in PDS header
Standard deviation image reported in PDS header

Our goal during the first quick look at the laboratory data was to establish how linear the output DN values were as a function of integrated target radiance. The default parameters selected below were selected to assess the linearity response of the laboratory UVVIS camera. Only gainid=1 and offsetid=0 data is being used. The target radiance was allowed to change in order to see its contribution on the output DN.

As it is shown below the system seems to show a highly linear response with number of collected photons. Nevertheless the erron in DN as defined below

error =

DN(photons|linear model) - DN(photon|actual camera)

generates an average error of

E[error]= 0.0 [DN]

with a standard deviation of

sqrt(var(error))= 0.7 [DN]