Monday, May 02, 2016

SAR image of the Calumet region of Chicago

I've been working on manipulating the large images offered by the Sentinel satellite. I found an image of the city of Chicago region on April 10th, 2016, and have been taking a look at it. The data image is 25000x16000. I grabbed the HH(the Horizontal transmitted, horizontal received polarization) and HV images (horizontally transmitted, returned vertical polarization), normalized them and made them R and B in an RGB set. The G I created by adding the two images together. Adjusting the hue allows for greater visual impact of the image. This is the Calumet region of southeast Chicago and Northwest Indiana, a heavily industrialized region. Lake Calumet, Lake Michigan, Wolf Lake, and the Calumet River/Cal Sag all show with no reflectivity at this normalization (you'll recall the previous post where Lake Geneva had some return from waves). The ArcelorMittal steelworks sits out on the right as a highly reflective region of pipes, stacks, rail cars and other industrialness, with the BP Whiting refinery to the left of it as another nearly continuous return. Long linear blue streaks are presumed oil or ethanol conveys consisting of mile-long packs of tanker cars that are bright in the HV channel. Shipping containers, barges, oil tanks and rail cars that are not tankers all reflect highly in the HH return. Even Binions Horseshoe floating casino shows up brightly. A bright return in the upper left I assume is the tower at Promet steel. blue-cyan-calumet

Wednesday, April 27, 2016

Synthetic Aperture Radar data of Lake Geneva, Wisconsin

I happened upon a nice description of how to grab data off of the ESA's Sentinel satellite via Evan Appelgate and there's a bunch of interesting things in the data. It was taken just this Tuesday morning at 7:11AM. The winds were out of the north at 8MPH and overcast. You can see in the image the effect of the wind creating a rougher, more radar scattering surface on Lake Geneva--dark at the north shore, transitioning to a very slightly rougher surface to the south.

Click to enlarge. There's a lot more interesting things to look at--that's just the first thing that jumped out at me.

Sunday, March 06, 2016

A really bad soldering iron

I picked this soldering iron out of the ewaste recycling stream that students dump at the end of the year, figuring I could use another iron. I knew it ran hot. Yesterday I was attempting to create a data cable between a PC and a radio and was annoyed at how quickly oxidized the tip had gotten. After cleaning it and trying again (failing ultimately because the PS/2 keyboard connector happens to not use one of the pins) I noticed a subtle warm color to it--and thinking it was just the orange light pollution reflecting off of it, but then I put two and two together and realized it was black body radiation. And that means this soldering iron is really really bad.
The camera appears to have a fairly good IR block filter on it, so the colors match better to the eye's response. On a weaker camera I would expect a purple appearance to it as the blue Bayer filter will pass IR circa 900nm.

Thursday, February 11, 2016

long term survelliance flights over Chicago

Perhaps you've heard of constantly circling Cessna planes, spending hours circling high above US cities. Today I happened to see many of them over Chicago. Looking at FlightRadar24's live feed I saw two. Their data is much more complete than my limited ADS-B receiving capability. The first was a Cessna, high at 9,000ft. It looks like it came from DuPage County airport, and has done a number of similar flights in the past few days. I was able to spot it in binoculars, and in doing so also picked up an identical looking plane holding an identical path, but not on ADS-B. I presume I was seeing a shift change, but one never knows. It had the 4414 squawk, and matched the false front company 'OBR Leasing'. Not only Cessnas, but a Bell 407 helicopter was hanging around too at a lower altitude further west, closer to Midway.