Ham Radio KML QSO Animated Map Time Stamps Restored... Almost Completely

This setting goals thing just might work.

The day after I set the goal to find a new time icon solution for the animated kml QSO maps a solution appeared. I was studying (again) the new Google Charts API, hoping it might be similar enough to the old visualization API to provide a solution—it was not—when I looked at the new map chart, more for the fun of it than for any other reason, and there it was: the answer I'd been looking for. Mind you, the answer was not in fact the chart API itself. The answer came in the form of map marker icons.

Allow me to give you a little background and/or catch you up. Google Earth Pro map animations are very cool. We use them to watch QSO frequency during POTA and SOTA activations, and have more than once used them to observe that our overseas QSO were in fact gray line QSOs. But, it's very difficult to see the tiny time indicator on the animation play controls.

That's OK though because there's a way to fix the issue. The kml screen overlay tag displays images on a map. Clearly, I just need an image that contains text designating each time of interest. With the deprecated chart API, this was a simple matter. The API returned PNG images intended to be displayed on web pages. I used the text bubble visualization specifically. It accepted an argument for the text it displayed. Simple. Then, it went away. (To be fair, the API has been 'deprecated' for a little over a decade.

So, I was back out on the streets looking for a way to get pictures of arbitrary timestamps from somewhere... anywhere really... on the web. Which leads us back to the new Google Charts API. For supported charts there's a getImageURI method that outputs raw PNG data representing the chart. (I'm going to use this method to display elevation charts, and therein lies the solution for displaying callsigns with the timestamps ala elevation chart titles... Anyway.)

That solution wouldn't work for timestamps thought, and as of today, there are no charts whatsoever that just dump out text. So, seemingly no solutions there, but wait! As I was browsing through the map chart docs, I noticed an offhanded reference to an online icon warehouse that could be used for map pins. It was exactly what I needed! I only had to browse the icon catalog for a few minute to find what I was looking for: a collection of 48 pixel wide icons each displaying a single decimal digit. To display a single one of these digits, I can use a URL like this:

https://icons.iconarchive.com/icons/twitter/twemoji-alphabet/48/Number-0-icon.png

To display the time down to the minute in the kml jinja template I used four blocks like this one:

<ScreenOverlay>
<name>Map Time{{loop.index}}</name>
<Icon>
<href><![CDATA[https://icons.iconarchive.com/icons/twitter/twemoji-alphabet/48/Number-{{ map_minute.11 }}-icon.png]]></href>
</Icon>
<drawOrder>{{loop.index}}</drawOrder>
<overlayXY x="0" y="1" xunits="fraction" yunits="fraction"/>
<screenXY x="0.10" y="0.1" xunits="fraction" yunits="fraction"/>
<rotationXY x="0" y="0" xunits="fraction" yunits="fraction"/>
<size x="0" y="0" xunits="fraction" yunits="fraction"/>
<TimeStamp>{{ map_minute }}</TimeStamp>
</ScreenOverlay>

And voila! The time labels are back!

More Cowbell! Record Production using Google Forms and Charts

First, the what : This article shows how to embed a new Google Form into any web page. To demonstrate ths, a chart and form that allow blog readers to control the recording levels of each instrument in Blue Oyster Cult's "(Don't Fear) The Reaper" is used. HTML code from the Google version of the form included on this page is shown and the parts that need to be modified are highlighted. Next, the why : Google recently released an e-mail form feature that allows users of Google Documents to create an e-mail a form that automatically places each user's input into an associated spreadsheet. As it turns out, with a little bit of work, the forms that are created by Google Docs can be embedded into any web page. Now, The Goods: Click on the instrument you want turned up, click the submit button and then refresh the page. Through the magic of Google Forms as soon as you click on submit and refresh this web page, the data chart will update immediately. Turn up the:

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain

The Valentine's Day Magnetic Monopole

There's an assymetry to the form of the two Maxwell's equations shown in picture 1. While the divergence of the electric field is proportional to the electric charge density at a given point, the divergence of the magnetic field is equal to zero. This is typically explained in the following way. While we know that electrons, the fundamental electric charge carriers exist, evidence seems to indicate that magnetic monopoles, the particles that would carry magnetic 'charge', either don't exist, or, the energies required to create them are so high that they are exceedingly rare. That doesn't stop us from looking for them though! Keeping with the theme of Fairbank[1] and his academic progeny over the semester break, today's post is about the discovery of a magnetic monopole candidate event by one of the Fairbank's graduate students, Blas Cabrera[2]. Cabrera was utilizing a loop type of magnetic monopole detector. Its operation is in concept very sim

Copasetic Flow

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