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Lake Tyers Temperature Profile
Lake Tyers Beach to Nowa Nowa

Beautiful Lake Tyers

Hi Folks,

Another experiment on the go!! This time I have measured the lake surface temperature from the Lake Tyers Beach Nos2 Boat ramp to the Nowa Nowa jetty. Gus and I set off this morning (13 Aug 2017) in very pleasant conditions (see photo above) and had on board an Arduino computer that was hooked up to a GPS unit and a Temperature Sensor. The GPS module has an SD card interface, so we could read the GPS and temperature sensor every second and save the readings onto the SD card to be analysed at our leisure when we got back.

The technology behaved quite well on the way up but completely stopped working about 10 minutes into the return trip (see updates below). However, for the moment the data is very interesting and worth repeating in about 3 months.

GoogleEarth view of our trip up Lake Tyers

As you can see the tracking was very accurate and corresponded to the Google Earth (courtesy Google Earth) view of the world when the data was overlaid onto it. This is quite reassuring feedback on quality of the Arduino GPS product. Google Earth is a fantastic tool, just incredible really. Using this tool, it tells us the trip from LTB#2 jetty to Nowa Nowa Jetty is 22.68km.

Graph of Temperature up the Lake
This graph is a summary of the temperature against readings (every second) so it does not quite relate to distance as we could not keep a constant speed (avoiding wild life and other fishing boats was a problem).
The main conclusion I believe to draw from this is the temperature climbed steadily as we went up the lake and from around 11.06ºC at the Nos2 Jetty to 13.94ºC at the Nowa Nowa Jetty. A rise of about 3 degrees. However the dip around 2556 (seconds) is quite interesting, with the temperature climbing quickly after that. The graphic below tries to convey the temperature on the map as a series of circles whose diameters are relative to the measured temperature.

Temperature profile at Lake Tyers

As you can see just as we were nearing Nowa Nowa, the quick drop to 11.31ºC in temperature can be visualised (courtesy GPS Visualiser) and then a quick rise to 13.94ºC just opposite the Nowa Nowa jetty. Why this is so could require some more detailed research, but is curious at the moment. People have talked of heated springs in this area, and I am quite happy to accept that statement given our data today.

I will include the Google Earth file and GPS Visualiser file for you own inspection.

Google Earth: Temperature Profile 13 August 2013
GPS Visualiser: Plotted Temperatures 13 August 2013 (every10th second)

I will be thinking about this data for some time and will probably publish updates if further ideas are generated. I welcome emails if anyone else would like to shed more light on the situation. rl dot ward (at) bigpond dot com.

UPDATE on System Failure

When the system stopped working on the way back Gus suggested it might have blown a fuse. I said it didn't have a fuse, however I had forgotten it has a solid state fuse that protects the Arduino voltage regulator from cooking itself. Gus was right and I was wrong. However it took until 8pm that night for the fuse to self heal, and when I went to work on what had gone wrong, it was all fine again. What really threw me was when I swapped it from the 12V battery, (that may have gone flat) to the 5V USB adapter plugged into the boat cigarette lighter socket, it was still totally dead. The fuse must protect both ways of powering the system. I won't forget this in a hurry. New power arrangements coming up!!  UPDATE: I have installed a software control of the LCD back-light so it can be switched off for most of the time and only on while actually checking progress. It works off one of the switches on the front panel.

UPDATE on Cool Spot

Close up of return journey near dip at Nowa Nowa
Here is as much data as I collected on the way back before the system collapsed. At least it captured the temperature dip again. So it has been repeated at least once!!

Close up of temperature dip near Nowa Nowa jetty
This plot graphic (courtesy GPS Visualiser) shows how sharp the dip in temperatures is. The data above was about as much as I got on the way back.

Update on Nowa Nowa cool springs (23 Aug 2017)

Temperature gradients at Nowa Nowa
This shows the temperature above and below the boat ramp at Nowa Nowa. The top end of the lake was tracked right up to the gravel race below the Boggy Creek Bridge (A). I did the two sections as different runs, both were South to North runs on 23 Aug 2017. The wind was light and surface currents would have been minimal. In the stretch above the boat ramp, the minimum shown was 11.5C (B)and the maximum was 13.63C (C) opposite the Boat Ramp, a range of 2.13C in about 200m. In the run down towards Lake Tyers Beach, minimum was 11.19C (E) and maximum was 13.88C (D), a range of 2.69C at that cool bend in the lake. So this confirms the larger variations in temperature around the Nowa Nowa end of the lake. Maybe the sensations of people that there are hot springs, is really that they are comparing sections of the lake with cool springs??

UPDATE on the Technology

Here are some photos of the gear I used to do it with:

temperature sensor taped to vacuum speedo sensor
Solid State Temperature sensor taped to vacuum speedo' sensor, using duct tape (of course!!!).

GPS Antenna taped to rod support at back of the boat
GPS Antenna "duct taped" to fishing rod support at back of the boat

Skipper Gus in action allowed to monitor the system
Gus skippering so I could monitor the readings, and check it was working (essential as it showed on the way back). The trip was in safe hands.

The Display and other electronics.
The 20x4 SPI Display and other electronics. The GPS board is in the middle layer, the temperature prototyping shield on the top, Arduino at the very bottom.

Solid State temperature sensor in its Stainless Steel housing
Solid State temperature sensor in its Stainless Steel housing

GPS Antenna
GPS Antenna
GPS Unit for capturing Temperature of Water on the move at Lake Tyers
Appearance of the final box with some readings. So temperature is 19.94C, #91 one second readings have been taken, 'Q' is the prefix for the file being used on the SD card (it increments through the alphabet on each start up) time 2hrs31mins03.00seconds (GMT) latitude is 37d51.44854mins E, and 148d05.12938mins W. It reliably takes 1 seconds readings in good reception areas without a glitch.

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Special thank you to the Arduino community for sharing all their good ideas with everybody else, Grazie ragazzi!!!