PDS_VERSION_ID        = PDS3                                                  
RECORD_TYPE           = STREAM                                                
OBJECT                = TEXT                                                  
  PUBLICATION_DATE    = 2018-03-14                                            
  NOTE                = "Description of the CALIB directory contents."        
END_OBJECT            = TEXT                                                  
END                                                                           
                                                                              
The CALIB directory contains all of the files required to produce the         
calibrated VIR VIS (1b/RDR) data from the uncalibrated (1a/EDR) data. Note    
that V2 of the VIS calibration data are identical V1, but are provided for    
consistency with the IR. A document describing the calibration procedure is   
provided in this archive in the DOCUMENT/VIR_CALIBRATION directory. A         
document describing the VIR internal lamp is provided in the directory        
DOCUMENT/VIR_LAMP_DESCRIPTION. This document contains information extracted   
from [MELCHIORRIETAL2003]. Additional information concerning instrument       
calibration and function which may affect data quality is provided in the     
data set catalog file, which is in the CATALOG directory. The following files 
and their PDS labels are provided here:                                       
                                                                              
DAWN_VIR_VIS_HIGHRES_SPECAL_V2.TAB    Wavelengths of the 432 bands of the     
                                      visible focal plane for high spectral   
                                      modes.                                  
                                                                              
DAWN_VIR_VIS_NOMRES_SPECAL_V2.TAB     Wavelengths of the 144 bands of the     
                                      visible focal plane for low spectral    
                                      modes                                   
                                                                              
DAWN_VIR_VIS_RESP_V2.DAT              DAWN-VIR VIS responsivity in            
                                      (DN*m^2*um*sterad)/(W*s)                
                                                                              
DAWN_VIR_VIS_SOLAR_SPECTRUM_V2.TAB    Solar spectrum irradiance for the VIS   
                                      channel, obtained from the convolution  
                                      of the Cebula+Kurucz spectrum with VIR  
                                      spectrum resolution using the           
                                      ENVI_RESAMPLE_SPECTRA procedure.        
                                                                              
DAWN_VIR_VIS_WIDTH144_V2.TAB          Wavelengths of the 144 widths of the    
                                      visible focal plane for low spectral    
                                      modes                                   
                                                                              
DAWN_VIR_VIS_WIDTH432_V2.TAB          Wavelengths of the 432 widths of the    
                                      visible focal plane for high spectral   
                                      modes.                                  
                                                                              
VIR_IR_CORRECTION_FACTOR.TAB          Correction factors that may be applied  
                                      to each band of the VIR L-1B VIS cubes  
                                      to correct for a positive slope in the  
                                      VIS-NIR range when compared to ground   
                                      based spectra of the same target (Vesta 
                                      and Ceres)