This is the Venus Express (VEx) Analyzer of Space Plasmas and EneRgetic Atoms,
4th edition (ASPERA-4) ELectron Spectrometer (ELS) Pitch Angle Distribution 
data bundle.  This bundle was produced with funding from NASA Solar System 
Workings (SSW) 2019, grant #80NSSC21K0151.

This bundle contains four collections, each of which is briefly described 
below.  Listed for each collection is a description of the type of data file 
contained.

browse_pad: This collection contains images of the VEx ELS pitch angle
        distribution,

    VExELSPADRG - These files are focused around the perigee of the Venus 
        Express spacecraft and are png images of small pieces of data.  
        They are not intended to be summary plots of the entire data set.  
        These images come in two types: Data and Mode.  Data plots show only 
        the 90-100 deg pitch angle data along with the data from the Venus 
        Express Magnetometer (not included in this archive).  Mode plots
        show how the PAD data was generated. 

data_pad: This collection contains the VEx ELS pitch angle distribution 
        data products.

    VExELSPADRG - The pitch angle sorted electron distribution.  This
        data is contained in two file types: Data and Mode.  The Data
        product is in ASCII Comma Separated Values (CSV) format, organized 
        as the step, energy, velocity, and 18 separate pitch angle 
        measurements.  The Mode product is in ASCII table with 38 columns
        which indicate how the data was processed.

document_pad: Documents that should be considered required reading
          for this bundle. There are two documents in this collection:

    VEX_ASPERA-4_ELS_PAD_Spec - This is the Software Interface Specification
        (SIS) document. It describes the archive contents and structure,
        including file naming conventions, LID formulation, standards
        used, and details of the data products and their formats.

    VEX_ASPERA-4_ELS_PAD_Fields.txt - This document contains a description of 
        the contents and fields within the Data CSV and the Mode txt files.

miscellaneous_pad: This collection contains two files: one document file and
        one multi-table document file.  The document file contains a description
        of the format of the table file and explains on how the tables were used
        to generate the PAD.
         
    ASPERA4Scanner_NYSA_Blockage - This document explains the miscellaneous
        table file format, how it was generated, and discusses the use of 
        the multi-tables.  The document file is written in ASCII and describes
        how the tables were used to generate the PAD.  

    ASPERA4Scanner_NYSA_Blockage_Tables - This document contains the 
        miscellaneous tables.  It is prefaced with some information about the 
        tables in this file, which is written as ASCII.  Represented in this 
        file are 361 tables, one for each 1 deg offset of the -Y solar array 
        on the venus Express spacecraft.  Each table is indexed by the ASPERA-4
        experiment's scanner location and each of the 16 sectors of the 
        electron spectrometer.  There are 181 values in each table for the
        ASPERA-4 scanner location and 16 blockage factors.  Values in the 
        tables represent the percentage blockage by the spacecraft and its 
        appendages.