Lew Payne's Technical Blog

Welcome to my technical blog. I created this blog to facilitate my ongoing research, by giving me a place to store useful research data. It also allows me to comment on various items as I work through their various implementations and determine suitability for my particular projects. Initially, my research was into Kalman filters; hence that is where the bulk of my commentary is located.

This blog is updated regularly, each time I run into something that is useful or substantive. While its format might not be ideal (since it grew to be more than anticipated), keep in mind that its main purpose is to allow me easy access to information that would otherwise be a pain to retrieve (not to mention difficult to integrate my comments into).

Major Categories


Antenna Fabrication:

Design a quarter-wave monopole.  Enclose the antenna in a fiberglass hollow rod or Sullivan pushrod sleeve.  Have the antenna flush against the body when retracted, via a servo mechanism that allows you to deploy it vertically after take-off (and retract before landing). The autopilot should auto-deploy and retract the antenna based on height AGL at the "take off" and "landing" locations.

There are two viable methods for retracting the antenna.  One is by employing a standard servo with 90 degrees of motion to change from vertical (deployed) to horizontal (stowed against the body); the other is by using a winch servo (VSD-22YMB, which can do up to 6 turns) with a kevlar line attached to the end of the antenna, effectively "reeling in" the end like a big fish.  This would not place the antenna flat against the body, but it would "bow it in" like a fishing rod.

Thin-wire radials (of one-half wavelength at the lowest freqency in use) should be impregnated in the wings and fuselage for use as a ground plane, rather than trying to secure an electrical connection to the epoxy-impregnated carbon fiber body/wings.

Another alternative would be to create a similar retract mechanism using a coaxial dipole instead (which would obviate the need for a ground plane - a requirement for the end-fed monopole).  In most cases, several ferrite beads (type 61 material) should be used where the coax meets the load, to prevent the feed line from radiating.

Antenna Miscellaneous:

  • MPU-6000 Tri-Axis Gyro + Accel + Fusion
  • HMC6343 Tri-Axis Compass + Accel with Algorithms
Test Platform:
Ground Station:
Standards - It would be nice to adhere to the following standards:
  • MIL-STD-1553
  • ARINC 429
  • Wind River VXworks RTOS?
  • See GE Ruggedized Systems