A graph I made of sunrise and sunset times on the first of each month for Santa Clara, CA. Since today is the Winter Solstice, it seemed appropriate to look forward to the lovely, longer days.
These are sunrise & sunset times on the first of each month.
I'm sitting at my desk in my home office, and I noticed strange red light coming in through the slats of the Venetian blind on the window. It looked fairly intense, as if coming from a good sunset. But it was not even 4 pm, and the sun sets on the other side of the building, so there's now way that's what it was.
So, I looked along the rays of light to see the source. Turns out, the afternoon sun was reflecting off a stop sign in the street below. I'm still not sure how the reflection occurred, since the sign is roughly perpendicular to the ground, and both the Sun and I are well above the sign, and both on the same side of it (left-to-right and front-to-back). Perhaps it's the nature of the reflective paint used.
Shooting the sign challenged my otherwise fairly capable digicam, a Panasonic Lumix DMC-ZS3. Interesting vertical lines appear prominent in the sign, as does a double image. The image was taken through a somewhat dirty window and screen, but the effect is barely noticeable (if at all) on other elements in the image.
Anyway, I thought it was pretty cool.
This weekend I'm working on a tracking antenna mount that we'll be using for our UAV and balloon tests in the next few weeks (months?).
Block diagram:
Here's what's inside. A MakeController and an alt-az gimbal mount that I don't think is available any longer.
The ports. Ethernet and USB (not sure which I'll implement) for the ground control computer to connect to, and power (may not be used either).
Here are the other parts. GPS (EM-408) , compass module (HMC6352), external GPS antenna (with a little MMCX to SMA pigtail):
Closeup of the GPS and compass module:
Getting all the stuff mounted in the enclosure has been a pain, and has taken much of the day (plus the Cal game, and other stuff). There's a lot of wiring to do still, and hopefully I'll actually get some code written this weekend. Stay tuned!
I've seen a lot of reports lately of recent and past amateur balloon launches. People have been launching sounding balloons with payloads containing GPS and cameras, and have been very successful. I've wanted to do this for some time, and coming across all these reports has excited me about the idea again.
Really what I want to do is launch a satellite. So I've decided to expand the scope of the balloon launch in support of a future satellite launch. I've ordered the Microhard radio we'll be using on the satellite to test on the balloon.
We're going to build a payload with GPS, temperature, pressure, still pictures, and possibly video. Lots of work to do in the link budget calculation to see what we can do, and within the 1.8-kg payload FAA limit. We're also building a directional 2.4 GHz antenna to automatically point at the thing (a project I began a couple years ago for UAV use).
This is going to be fun. Check back for updates.
MissionClock has been in the iTunes App Store for a few weeks now, and I thought I'd post some sales information. The chart below shows the relative number of unit sales per day from July 30, 2009 to September 10, 2009. The two big spikes in sales corresponded to the STS-128 launch attempt on August 24, and the actual launch on August 28. Labor Day was particularly bad. There is no data for the dates from August 5 to August 8.
Clearly, launch days are good for MissionClock.
