The Great Spacecraft Base Input Vibration Test Debate

Engineers prepare the MESSENGER spacecraft for a vibration test at The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., where the Mercury-bound NASA spacecraft was designed and built. * * * Introduction Flight configured spacecraft are subjected to base input vibration tests for certain programs.… Read more

Lithium Battery Vibration Hazard

N571UP, the aircraft involved, seen taking off from Dubai in November 2008 * * * A UPS Boeing 747-400 flying between Dubai International Airport and Cologne Bonn Airport crashed close to Dubai airport, killing the two crew members, on September 3, 2010. The aircraft had… Read more

Sharing our Light

At times our own light goes out and is rekindled by a spark from another person. Each of us has cause to think with deep gratitude of those who have lighted the flame within us. ~Albert Schweitzer * * * I met a stranger in… Read more

Weather Radar Matlab Scripts

I may have an upcoming opportunity to perform signal processing on some satellite data for tracking storms and ocean wave heights… Anyway, I am studying some radar books in preparation. * * * Here are some Matlab scripts for monostatic pulsed radar systems: target_range.zip -… Read more

Matlab GUIDE Tips

Matlab GUIDE is a package for generating graphical user interface (GUI) scripts. Extracting Numerical Data from a Matlab uitable The table format was set to text using the Table Property Editor. The number of rows is equal to N. There are three columns of data:  peak,… Read more

Matlab Plotting GUI

Matlab has very good plotting capabilities, but the required command syntax is somewhat awkward. Here is a hopefully user-friendly GUI for plotting XY curves from array data. The data must have two columns. Typical applications would be for a time history or frequency response function.… Read more

Singing Plumbing Pipes

Alas, the water drainage pipes in my home have developed a singing sound with a frequency of 400 Hz.  This is slightly above a G note on the musical scale.  The singing occurs when someone has finished taking a shower on the second floor. Here… Read more