# Home

M.Eng. René Schwarz

Dear Visitor,

welcome on my personal website. You can find some information concerning my scientific work and interests, mainly covering the areas of astronautics and space science, aeronautics, computer science, and math, as well as information on myself here.

I was born and raised in Merseburg, Germany, where I also received my Bachelor's degree in Mechatronics, Industrial and Physics Technology (Bachelor of Engineering, B.Eng.) in 2009 as well as my Master's degree in Computer Science and Communication Systems/Artificial Intelligence (Master of Engineering, M.Eng.) in 2012 at the Merseburg University of Applied Sciences. Since the end of my university education, I am living and working in Bremen, where I am employed as a research scientist and engineer at the Institute of Space Systems of the German Aerospace Center (DLR). My current main fields of work in the Department of Guidance, Navigation and Control Systems are the systems engineering for high-reliable guidance, navigation and control (GNC) appliances as well as the high-precision simulation of attitude and orbit control (AOCS) systems together with the accompanying software engineering. I am currently also doing a doctorate on these fields.

Students of the Merseburg University of Applied Sciences may find some materials that I prepared during my study time for the courses mentioned above within the category “Science”.

Please do not hesitate to contact me in case of questions, criticism, errors or any other concerns. You may find my contact information here.

— M.Eng. René Schwarz

## New Blog Posts

DLR Pictures of the Year 2016
René Schwarz (talk), 21 January 2017 12:07

New Memorandum "Quaternions and Spatial Rotation" Released
René Schwarz (talk), 29 October 2014 16:42

Preview of Memorandum #6: Quaternions and Spatial Rotation

The Memorandum "Quaternions and Spatial Rotation" has been published as part of my Memorandum Series. It provides a compact introduction into quaternions and their application for spatial rotations:

• brief introduction into quaternions, their components, notations, and properties
• quaternion algebra formulary summarizing
• basic properties (quaternion equality, hypercomplex conjugate, norm, and inverse)
• basic operations (quaternion addition and subtraction, multiplication, division, normalization, cross and dot product)
• exponential and logarithmic functions (quaternion exponential function, natural logarithm, logarithmic functions, power and root functions)
• trigonometric and hyperbolic functions of quaternions
• application of quaternions in the context of spatial rotations, quaternion rotation operators, rotations and transformations
• conversion algorithms:
• Euler Angles to Quaternion (for all 12 possible rotation sequences)
• Quaternion to Euler Angles (for all 12 possible rotation sequences)
• Direction Cosine Matrix (DCM) to Quaternion
• Quaternion to Direction Cosine Matrix (DCM)
• Euler Angles to Rotation Matrix (for all 12 possible rotation sequences)
• time derivative of a rotation quaternion
• quaternion interpolation algorithms
• linear interpolation (LERP)
• spherical linear interpolation (SLERP)

Have a look here if you are also interested into other Memoranda out of my Memorandum Series.

DLR-Jahresfilm 2013
René Schwarz (talk), 23 February 2014 16:29

OpenPGP Key Transition
René Schwarz (talk), 11 August 2013 18:47

In the light of the recent occurences in the domain of computer security, I will hereby replace my old OpenPGP key by a new and stronger key. The old key is invalid with immediate effect and I recommend to use my new one for all future correspondence. Please see my key transition notice here for further details:

Unfortunately, Moxa's NPort Real TTY Driver for Linux is currently (version 1.18, released 2012/03/20) not compatible with Linux kernel 3.8.0. When I tried to install this driver for the NPort 5450 Serial to IP Server on my Ubuntu 13.04 machine (currently with kernel 3.8.0-27), the driver didn't compile. It turned out, that it is possible to patch the driver source code in order to get it work with Linux kernel 3.8.0 – here is a short documentation what I did.

New Memorandum on Astronomical Constants Released
René Schwarz (talk), 24 July 2013 14:18

In endeavor to extend my Memorandum Series, I published a new Memorandum on astrodynamical constants, listing commonly used constants in astrodynamics as well as in space science and engineering with their latest values according to recent publications. This Memorandum is going to be updated with new constants from time to time.

Have a look here if you are also interested into other Memoranda out of my Memorandum Series:

Upcoming:

• M004: Conversion between Gregorian and Julian Dates
• M006: Quaternions and Spatial Rotation

René Schwarz (talk), 23 July 2013 16:41

Book cover

After one year of having missed to update the page on my Master's Thesis, I am finally pleased to announce the availability of my master's thesis „Development of an illumination simulation software for the Moon's surface: An approach to illumination direction estimation on pictures of solid planetary surfaces with a significant number of craters“ as book both in form of a free download (PDF file) and in form of a printed paperback copy over the book trade.

php_mailparse.dll for PHP 5.4.x (VC9 version) available
René Schwarz (talk), 17 May 2012 14:45

I'm pleased to announce the immediate availability of a precompiled php_mailparse.dll for the PHP 5.4.x series, built with VC9. This version is compatible with the standard 32-bit binaries of PHP for Windows.

Please notice the instructions written here (they are valid for the new version too).

Breathtaking Time-Lapse Aurora Video in Norway 2012
René Schwarz (talk), 7 February 2012 13:56

Today I've seen this breathtaking time-lapse aurora video made in Norway, January 2012, by Christian Mülhauser. It is so fascinating, that it would be a shame not to share it with you.

Many thanks to Christian Mülhauser for his efforts!

Misleading Output of MySQL Profiling Feature
René Schwarz (talk), 30 January 2012 15:23

During the ongoing work on my Master's Thesis I noticed a bug in the MySQL profiling feature: The output of the SHOW PROFILE statement is misleading, since the presented durations are not given for the status in the same row, but the durations are given for the previous status!