Public Lab Research note

Flight Temperature

by cfastie | October 08, 2012 23:26 08 Oct 23:26 | #4260 | #4260

A Jeenode is a tiny programmable computer with the same type of processor (8-bit Atmel RISC microprocessor) as an Arduino, and connectors for four sensors. During a 40 minute kite flight at LEAFFEST a Jeenode was recording temperature and barometric pressure about once per second and also recording x, y, and z data from an accelerometer. You can sort of see the Jeenode under the red tape in the above photo of the rig we flew that day.

Don sent me the data yesterday, and I matched up the temperature series with the data from a GPS watch on the rig and dragged it kicking and screaming into Google Earth. I need help finding a more elegant way to produce a KML file from this sort of data.

I was hoping that Google Fusion Tables would help with this task because it does a good job making Google Earth KML files from spreadsheet data if they include GPS coordinates. But it appears that Fusion Tables do not support 3D GPS data (lat, long, and altitude). Maybe Google Spreadsheet Mapper will do it, but I have never figured out how to use that. So I had to construct a separate KML file for each different segment of the colored GPS track. If anyone knows a better way to get a colored path like this into Google Earth, please let me know. The temperature data vary continuously, but I dumped it into five bins to make my job simpler. It would be nice to see the continuous variation.

You can download the KMZ file of the color coded GPS track (without the MapKnitter overlay) and view it in Google Earth. There is a recorded tour included (double click on it) which flies in a circle around the kite track.

If you examine the track carefully, you can probably tell which way the KAP rig was moving through the air.


Hi Chris,

I'm not sure what you mean exactly by "finding a more elegant way to produce a KML file from this sort of data" but I expect GIS software would do the trick. QGIS is an open source GIS package and it can create a KML file from a CSV file (easy to create from a spreadsheet or fusion table) with coordinates and any attributes you want to tie to the coordinates. I'm happy to help with that if you want to give it a try.

Did you get the data from the accelerometer too? An accelerometer doesn't actually give x, y, and z coordinates (at least not directly) but it can provide useful data for evaluation rig stability which is an application I hope to play with if I ever get around to building a pendulum.

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Hi Ned, We have the data in pretty good shape in a Google Doc: Other tabs in that spreadsheet include the GPS data (lat, long, alt) which has been matched up with the temperature and pressure from the Jeenode. The accelerometer data have not been matched yet. There is no time stamp on the Jeenode data, and it was recording points 2 to 2.5 times more frequently than the GPS watch, so I did some crude visual matching of GPS elevation and Jeenode pressure to synchronize the data.

Using GIS to visualize these data is a good idea. I could not figure out how to make a KML file that colors each path segment or point as a function of temperature. So displaying such data in Google Earth might require simplification, as I did above. I was hoping to get it done in Google Earth because that is a good way to share the data and allow others to extend the analysis.

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Chris, really neat. Again, I love the fusion of the gps info with the fly-through point-of-view. Now I see how the temperature data was integrated into the flight track with color coded scale. Pat

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