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PDS_VERSION_ID               = PDS3                                           
RECORD_TYPE                  = STREAM                                         
INTERCHANGE_FORMAT           = ASCII                                          
                                                                              
INSTRUMENT_HOST_NAME         = "CASSINI ORBITER"                              
INSTRUMENT_HOST_ID           = "CO"                                           
INSTRUMENT_NAME              = "MAGNETOSPHERIC IMAGING INSTRUMENT"            
INSTRUMENT_ID                = "MIMI"                                         
                                                                              
OBJECT                       = ASCII_DOCUMENT                                 
  DOCUMENT_NAME                 = "LEMMS FINE RATES ALGORITHM DESCRIPTION"    
                                                                              
  DESCRIPTION                   = "(Title page information follows.)          
    ----------------------------------------------------------------------    
                           Cassini Mission                                    
                   Magnetospheric Imaging Instrument                          
                   LEMMS Fine Accumulation Rates Algorithm Description        
                                                                              
                              Version 2.0                                     
                         rev. February 28, 2005                               
                                                                              
                          J. W. Manweiler                                     
                     Fundamental Technologies, LLC                            
                       Lawrence, KS 66046                                     
    ----------------------------------------------------------------------   "
                                                                              
  PUBLICATION_DATE              = 2005-03-01                                  
  DOCUMENT_TOPIC_TYPE           = "ALGORITHM SPECIFICATION"                   
  INTERCHANGE_FORMAT            = ASCII                                       
  DOCUMENT_FORMAT               = TEXT                                        
END_OBJECT                    = ASCII_DOCUMENT                                
END                                                                           
                                                                              
FILE CONTENTS: Calibration algorithm for PDS data products containing         
               Cassini/MIMI/LEMMS Fine Accumulation rates                     
                                                                              
AUTHOR: Jerry W. Manweiler, Ph.D., Fundamental Technologies, LLC              
                                                                              
DATE: 03/01/2005                                                              
                                                                              
INTRODUCTION:                                                                 
This file contains a text and pseudo code algorithm to covert the counts      
contained in the Cassini/MIMI/LEMMS Level 1A accumulator rates PDS data       
products into particle fluxes.                                                
                                                                              
                                                                              
FLUX EQUATION:                                                                
See below for general information on Cassini/MIMI Level 1A calibration. If you
have not read this information, it is highly recommended that you do do now.  
                                                                              
flux = (count-background)/(duration*factor*geom_fact*(ehi-elo))               
                                                                              
RESULT VARIABLES:                                                             
flux: the result of the calibration in nucleon/(mm^2*sec*sr*MeV)              
                                                                              
INPUT VARIABLES FROM A DATA PRODUCT:                                          
count: dp:LACC:"sci":[detector_channel], a count from a LACC data product     
                                                                              
duration = dp:LACC:"sci":["End_Ephemeris_s"]-["Start_Ephemeris_s"],           
        the calculation of the Duration from a LACC data product in seconds   
                                                                              
INPUT VARIABLES FROM A CALIBRATION FILE:                                      
ehi: cdf:"ENERGY":"ACC":"LEMMS":(detector_channel):(detector_channel_no):     
["Hi"], the pass band high energy in KeV/nucleon                              
                                                                              
ehi: cdf:"ENERGY":"ACC":"LEMMS":(detector_channel):(detector_channel_no):     
["Low"], the pass band low energy in KeV/nucleon                              
                                                                              
geom_fact: cdf:"GEOM_FACTOR":"ACC":"LEMMS":(detector_channel):                
(detector_channel_no):["Midpoint_Value"] the geometrical factor in cm^2*sr    
                                                                              
VARIABLES TO BE PROVIDED BY DATA USERS:                                       
factor: a catch all scaling factor used to account for detector efficiencies  
        and other phenomenon that cause count rates to be lower than they     
        should be based on geometrical factors and pass bands. A generalized  
        formula cannot be easily described to allow for the specification of a
        "cookie cutter" algorithm due to the complexity of evaluation of all  
        factors that might exist to reduce the effectiveness of the sensor. In
        general, Using a factor of 1.0 will produces fluxes not corrected for 
        the phenomena expected to reduce the overall ability to count         
        particles.                                                            
                                                                              
background: A representation of the expected background radiation counts due  
            to other sources including but no limited to cosmic rays, gamma   
            radiation, etc.  In general a significant amount of effort is     
            required to develop an understanding of the background count rates
            observed during any particular phase of the mission.  There is no 
            one set of "cookie cutter" algorithms that can be used to derive  
            the background rates for any particular instrument.               
                                                                              
GENERAL Cassini/MIMI CALIBRATION:                                             
Each data product type in the PDS Cassini/MIMI Level 1A data set has two      
associated calibration files: a calibration algorithm file that is specific to
each sensor and a calibration data file that is specific to the instrument.   
Each calibration algorithm file (this file) contains a text and pseudo code   
algorithm that describes how to calibrate the Level 1A data. The calibration  
data file is a CSV file that contains data values used in the algorithm       
described in the calibration algorithm file.                                  
                                                                              
All records for a data product type in the PDS level 1A files and the         
calibration data files have the same format. The first field in each record is
the purpose field. The purpose field indicates the intended use of the record.
For example records containing science data have a purpose field with the     
value "sci" and a record containing the geometrical factors of the detectors  
in a sensor would have "geom" in the purpose field.                           
                                                                              
All MIMI calibration algorithm files use a short hand notation to refer to    
fields in the data products and calibration data files. This shorthand        
notation consists of an instrument/data type, a file type, a purpose field    
value, and a column description. This notation is used to specify types of    
fields, in types of records, in types of files. This notation allows the      
algorithm file to specify the relationship between types of fields in various 
files. The syntax and examples of this notation are given below.              
                                                                              
SHORTHAND NOTATION:                                                           
❮file type❯:❮sensor data type❯:❮row field value 1❯:❮row field value 2❯:...:   
❮row field value n❯:[❮column id❯]                                             
                                                                              
where:                                                                        
❮file type❯ = dp or cdp where dp = data product and cdp = calibration data    
              product                                                         
                                                                              
❮sensor data type❯ = CACC, CPHA, CSCI, IACC, IIMG, IPHA, IACC, LFRT.  The cdp 
                     does not include a ❮sensor data type❯ identifier.        
                                                                              
❮row field value x❯ = a specification of a particular value of a row in order 
of left to right for those rows that apply. It is notec that not all rows     
apply for each value. Literal values of identifiers are placed in double      
quotation marks. Variable values are in parenthesis "( )".                    
                                                                              
❮column id❯ = a column identifier (label) to be used to select the final      
unique value based upon the combination of row identifiers and the specific   
column that has the data value. Literal values are placed in double quotation 
marks. Variable values are in parenthesis "( )".                              
                                                                              
examples:                                                                     
     dp:IACC:"sci":["Start_Ephemeris_s"] =                                    
        The starting time of the record with a single row identifier of "sci" 
                                                                              
     dp:IACC:"sci":("Start_Ephemeris_s"):[(datacolumntype)] =                 
        A field representing a specific column of counts for a record that    
        includes "sci" and a starting time in the column that uses the literal
        for the start time in a column that identifies the source of the      
        counts.                                                               
                                                                              
     geom_factor = cdf:"GEOM_FACTOR":"ACC":"INCA":"DETECTOR":("Particle"):    
     ("Start_Year"):("Start_DDOY"):["midpoint_value"] =                       
        Select the value of the geometrical factor using the literal          
        "GEOM_FACTOR", "ACC", "INCA", "DETECTOR" rows and the variable rows   
        for start year and DDOY (decimal day of year) in the column of        
        "midpoint_value".