Lake
Tyers Temperature Profile
Lake Tyers Beach to Nowa Nowa
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.
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.
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.
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
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!!
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)
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:
Solid State Temperature sensor taped to vacuum speedo' sensor, using
duct tape (of course!!!).
GPS Antenna "duct taped" to fishing rod support at back of the boat
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 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
GPS Antenna
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.
Special thank you to the Arduino community for sharing all their good
ideas with everybody else,
Grazie
ragazzi!!!