Characterization and Improvement of the SPICE Kernels from the Deep Impact Encounter with Comet Tempel 1

Brian Carcich, Latchmoor Services LLC, working for Dr. Tony Farnham of UMd

Understanding what the DI SpaceCraft cLocKs (SCLKs) were doing around encounter.

========== QuickStart

Click here to jump directly to the results

=====

===== Usage

0. Prerequisites:

0.1) Python 2.7

0.1.1) Python modules: numpy; scipy; pyfits; matplotlib; PySPICE.

0.1.2) PySPICE (misc.py, object.py, _spice.so, build from Git repo https://github.com/drbitboy/PySPICE) in spice/ subdirectory of this directory.

1. Read 00readme.txt (this file), doc/00readme.txt, kernels/00readme.txt, and follow recommendations and read additional materials referenced.

======== Manifest

Documentation

00readme.txt, Readme.md - this file

doc/ - Directory containing documentation for this project

doc/00readme.txt - Descriptions of those documents

SPICE kernels

kernels/ - SPICE kernels (SCLK, LSK, SPK)

kernels/00readme.txt - description of SPICE kernels

DII and DIF SCLK (time) and SCU temperature data

all_scutemp.txt, dif_scutemp.txt, dii_scutemp.txt - Temperature data

dii_dif_diffs.txt - DIF and DII SCLK summary clock correlation data

Python scripts

ttmodel.py - Implements two-parameter time model for DI SCLKs

timediffs.py - Module with Classes to read and difference DII and DIF times

smoothtemps.py - Module with Classes to read and smooth DI temperatures

readtemps.py - Python module to read DIF and DII temperatures

spice/ - symlink to PySPICE/spice/ - allows 'import spice' in Python code - not part of repo - see https://github.com/drbitboy/PySPICE

check_00.py - Test script comparing DII, DIF SCLKs and VTCs from kernels

check_01.py - "

check_02.py - "; also plots data

doc/fit2png.py - Script to locate MRIVIS flash; uses doc/mrivis/*.fit

============= Abbreviations

DI - Deep Impact (mission, project, spacecraft)

DII - Deep Impact Impactor spacecraft

DIF - Deep Impact Flyby spacecraft

TOI - Time Of Impact

S/C - SpaceCraft

SCU - S/C CPU

SCLK - S/C clock representation e.g. '1/0123456789:012'; see SPICE

VTC - Vehicle TimeCode, Floating point representation of S/C seconds

SPICE - Toolkit (code) and kernel files (data) for describing ancillary info about spacecraft observations; see http://naif.jpl.nasa.gov/

=============== Git cheat sheet

git commit -a -m "..." git push -u origin master