Stanford, CA


Chicago, IL

Activity Feed

Geoff commented on Jaeyoung Lim's blog post Non-planar quadrotor layout flight test!
"This configuration is not symmetric about all of the body axes. The vertical separation of two neighboring motors introduces cross moments of inertia when expressing the inertia tensor in the body axes. If the x-axis is to the right or left in your…"
Oct 21, 2015
Geoff commented on JLJu's blog post The impact of humidity on airspeed measurement
"You should not be scheduling gains on true airspeed! The aircraft dynamic scale with dynamic pressure, which is essentially the same as the impact pressure measured by a pitot-static system at the speeds model aircraft / small UAS fly. The only…"
Jun 5, 2015
Geoff commented on Chris Anderson's blog post $300,000 for a Raven?
"There are multiple airplanes in each system, four I believe. The $35,000 for each airplane sounds about right, the rest is for GCS, training, spares, etc..."
Dec 29, 2010
Geoff replied to Geoff's discussion MediaTek Mode
"That problem is solved. Just needed to bump up the baud rate from my PIC to computer to be equal to or faster than the GPS to PIC so data won't get lost...

Next question, what are the commands to do the following:
1. Change the baud rate
2. Change…"
Sep 23, 2010
Geoff posted a discussion
I'm testing the the MediaTek GPS module on a project where it is communicating with a dsPIC33F microcontroller.As understand it, some of the units have been flashed with a custom firmware that communicates with a binary protocol. After figuring out…
Sep 23, 2010
Geoff commented on Geoff's blog post UAV Altitude Record
"The cracked clay is on Rosamond Dry Lake down at Edwards AFB.

The barometric pressure and GPS altitude tracked each other very well, but the absolute numbers are usually offset a little due to local weather conditions. On the 7000 ft flight the…"
Sep 20, 2009
Geoff commented on Geoff's blog post UAV Altitude Record
"As used for the class it was a GPS only autopilot. It was flown in both of the airplanes shown above, plus about 6 others the team's built throughout the quarter. Since it was an aircraft design course, part of the challenge was designing a…"
Sep 19, 2009
Geoff posted a blog post
Hi all,Just wanted to fill you in on a small UAV altitude record that was just set (still unofficial at the moment) using an autopilot similar to the ones discussed here. Here's a story about it:…
Sep 19, 2009
Geoff left a comment for Rob
"Not much, what are you up to? Planning on building a UAV?"
May 10, 2009