April 2012
4 posts
Fontaine Maru is not in Sunnyvale
Only its brain is :-) we swapped out the command-and-control unit and shipped it back to Sunnyvale. Fontaine is happily in Hawaii running with a transplanted brain. The old brain is being worked on in Sunnyvale. The software generating the data that goes into ERDDAP currently doesn’t track changes in vehicle ID numbers (we currently use the IMEI number from the Iridium modem). Yet...
navytim asked: What is the GPS update rate for the gliders? Does it vary or do you keep a steady schedule? What do you use to monitor the weather patterns that the gliders may encounter? Is the speed data that you get from the gilders an average or an instantaneous speed? The data is great, keep it up!
Windows App for Tracking PacX Data
As I mentioned earlier, a super fan of ours created an HP Touchpad app for the PacX data, after a few weeks of working on it he successfully ported it over to Windows! Go ahead and visit his website to check it out for yourself.
eakmetoc asked: I heard about this via and article my Mom sent me from the WSJ. I teach Oceanography for the University of Phoenix and formerly I was an Oceanographer for the Navy. I am SO excited about this experiment. I live in Guam so if you or your team ever find the need to come this way please let me know I'd be happy to be the local on the ground to help you out. .... do you have a fan page on...
March 2012
9 posts
polarjacksw asked: When looking on your screenshot of your Robot Visualizer, we can see "Papa Mau", the missing glider, not far from "Piccard Maru" with a date 8 March (after the end of data available from iridium). Is that meaning you are able to continue to follow the "Papa Mau" glider with GPS data and no iridium emission ? How did you collect data ? Did you plan to rescue also this...
polarjacksw asked: What's happening for the Piccard Maru Wave Glider ? Since the 5th of March, the ruddercount seems locked, the glider goes to North even with a desired heading is South and Pressure Sensor , Submarine Temperature and Heading are 0 !!! Something is broken ?
polarjacksw asked: For the "PowerStatus" dataset, there is a strange thing about "Solar1" & "Solar2" (milliwatts) since the 2012-02-11. A couple of values are negative and lower than -32000 during the daylight (ex: Fontaine Maru @ 2012-02-11T21:51:42Z Solar1=12917.0, @ 2012-02-11T22:51:42Z Solar1=-32009.0 and @2012-02-11T23:51:36Z Solar1=28216.0). When looking the variation, it...
Wave Gliders ready for some Aloha
All four Wave Gliders have now reached Hawaii and broke the world record! Some made it in a more exciting fashion than others, so it’s time for them to get a little spa treatment while in Hawaii.
Fontaine and Benjamin arrived under their own steam at our test area off the Big Island near Kona, and Ben was greeted with some fanfare from the local press.
Piccard Maru got pretty close but ran...
PacX HP Touchpad App
Easily one of the coolest parts about projects where you open your data to the internet, like the PacX challenge, is seeing what the community comes up with. So we’re proud to promote one of the first PacX apps (that I’ve seen) built outside of Liquid Robotics.
The app was created by Polar Jack Software, an independent developer in France. He is easily our biggest fan as sometimes it...
polarjacksw asked: Where the Gliders are going ? Since 2 or 3 days, the Cap has changed for Fontaine Maru, Piccard Maru and Benjamin. There are not going to the buoy south of Hawaii through the Alenuihaha Channel between the two main islands, but it seems that there are going right to the main island.
February 2012
6 posts
New Game: Identify the Stowaway!
We regularly take pictures from the PacX Wave Gliders as you may have noticed, but something very interesting happened this time - We found a stowaway! We have no idea what this little critter is, we’re hoping you all in the internet world can help us identify it for us. Here are the pics:
We weren't alone in the storm!
In our previous posts we mentioned the major storm our Wave Gliders went through, and we just recently found out that we weren’t alone out there! We learned that there was a Canadian family that was rescued by a container ship in the same vicinity (~600 Miles away) as our Wave Gliders.
We’re not sure if our Wave Glider data could have helped them in this instance. Maybe we could have...
100 Knot Winds!!
Up to now the Wave Gliders have not seen any horrible weather, conditions have been ideal. Starting in early February, the vehicles encountered their first significant storm. In the images below you can see wind gusts between 40 and 100 knots starting on February 5th. This is coincidental with the barometric pressure dropping below 1000 mb for Papa Mau and approaching 980 for Piccard Maru. A...
polarjacksw asked: When computing the solar position corresponding to "Benjamin venturing west Sunday morning, January 29, 2012 at 16:18z", it seems that the sun is under the horizon (Zenith Distance: 93.18°, Azimuth: 114.56°). Is it really the correct time of the picture ?
michaelkoopmans asked: When a wave spectra is calculated, isn't a response amplitude operator utilized? Where does the Datawell sensor get this information? Or has Liquid Robotics estimated this statistic using a combination of wave tank testing and computer simulations?
January 2012
18 posts
tritonimaginginc asked: Hi - just started looking at this so forgive me if this has been asked before. There is now a considerable spread in positions between the 4 vehicles of 200+ miles. Any thoughts on why?
michaelkoopmans asked: After analyzing Waveglider Ben's significant wave height estimations vs. the Half Moon Bay buoy no. 46012 during 11/17 18:00 - 11/19 22:30, I found a data set ~3 weeks old was much worse than one I downloaded yesterday. What kind of modifications were made to the data set this long after recording and why?
regexguy asked: Can the robots be used to measure bathymetry (depth)? It would be useful for storm surge modelling if they could give us good data for depths of 10m or less along the coast.
bgcahill asked: How do the Wave Gliders measure water surface elevation and how are the wave parameters calculated (spectral analysis or zero crossing method etc.)?
polarjacksw asked: When looking inside the kmz file, how to now the route of each glider ? There is only one vehicle "Vehicle: 372" and one list of Way Points (WP?) in reverse order. I suppose that "WP: 246" is the current objective to all four gliders.
suzzzz asked: Are humans descendants of whales?
polarjacksw asked: Finally, after correcting my distance algorithm computation and removing the redounded data from the Power Measurements dataset, hereafter is the "estimated" date of the first crossing 1000 Nm for all four Wave Gliders: - The winner is "Papa Mau" @ 2012-01-04T20:26:38Z, -The second is "Benjamin" @ 2012-01-05T02:43:23Z, -The "Fontaine Maru", after a period of...
polarjacksw asked: Anomaly on data when the request includes days between 2011-12-31 and 2012-12-03, a sequence of data from 2011-12-31T08:58:55Z to 2012-01-03T21:55:50Z is repeated two or three times with the same values. This anomaly is existing on each dataset even for the Hermes dataset. It seems that the database has troubles. So, when I compute the distance from the start, I find a big error.
polarjacksw asked: If I have correctly computed the distance since the departure of the four gliders on the 17th of november, the "Fontaine Maru" will cross the barrier of the first 1000 Nm today (27th of december).
michaelkoopmans asked: When you command a Wave Glider to circle a buoy and thus generate comparable data, how many laps have you found to be necessary for a statistical correlation? Also, what information do you consider when setting the relative spacing of the Wave Gliders as they journey towards Hawaii?
polarjacksw asked: Sorry, I have done a mistake during the computation of the distance. In fact, I have mixed longitude and latitude. Instead of having two gliders with more than 1000 nautical miles, I have recomputed and the Fontaine Maru distance is 1691.2 kms @ 2011-12-29T17:46:40Z.
polarjacksw asked: Fontaine Maru Glider has crossed the first 1000 Nm on 2011-12-28T19:46:23Z.
polarjacksw asked: For the "Standard telemetry reports" dataset, there is another strange thing about "totalPower" (milliwatts) after a long increase from 20th to 22nd of december (max 32429) the value fall to a negative value (min -32536). When looking the variation, it seems that there is a bad conversion into signed integer instead of unsigned integer.
michaelkoopmans asked: Why was November 17th chosen as the PacX launch date?
Dissolved oxygen is wrong
We’ve realized that the current computation of dissolved oxygen has some errors. The instruments are calibrated OK, it’s just our conversion from that to DO. This will be fixed and the database regenerated to reflect the corrected DO. Not right away though :-)
@anthonygoddard asked: how come the 'ship' dataset...
For this AIS data there are two answers, one lame and one open to debate. The lame one is that the datastore from which the erddap data is derived doesn’t provide “observing glider” information. The other is roughly “why would you want to?”. For example, in the case of gliders operating in fleets (like PacX) the gliders probably all see the same ships, but some...
December 2011
12 posts
See PacX Progress in Google Earth →
We’ve posted up a Google Earth KMZ that shows the planned route for the robots and their progress so far. There’s a looong way to go, but at least they’ve made a pretty good dent.
At the moment it looks like they’re fighting a surface current that’s as much as a knot, but they’re still tracking West at about a quarter knot over ground.
polarjacksw asked: For the "Standard telemetry reports" dataset, there is a strange unit for the "waterDirection" (degree_C instead of degrees_true ?) But the value is often equal to 999.0 (meaning NAN ?)
vanderbeek asked: How do I track the progress in Google Earth?
benfromtomales asked: It appears that there is no CTD data from the last few days for any of the vehicles. However, the blog shows a figure with recent water temperature measurements. Where can these be downloaded?
benfromtomales asked: In the "Standard Telemetry Reports" what are "waterSpeed" and "waterDirection"? "waterDirection" correlates closely, but not exactly, with "headingSub," suggesting it is dependent on the orientation of the vehicle, and "waterSpeed," with reported units of m/s, varies between integer values of about 1000 and 1800.
They're off!
The last engineering sign-off happened the night before last and yesterday morning the PacX wavegliders headed out of Monterey Bay for Hawaii. They’ll be collecting piles of data along the way. Every now and then they will pause to do a few laps around mid-ocean buoys to get sensor correlations. It’s been somewhat cloudy, so we’ve had to turn some instruments off to save...
Maintenance done!
The work to remount the Datawell MOSE wave sensor was completed yesterday and all four PacX wavegliders seem to be working perfectly. Right now we’ve got them circling a couple of buoys in Monterey Bay that also have wave sensors. With luck, the data from our wavegliders and the buoys will correlate :-) One of the buoys is run by a scientific group and has exactly the same sensor on it as...
Engineering data added
A whole pile of engineering telemetry got added to the ERDDAP data store, streaming continuously from the wavegliders. Some is under the “basic” category, the rest is under “PowerStatus”. The solar panel measurements are a useful proxy for the amount of sunlight falling on the wavegliders. eg. fit a curve, find the peaks, and calculate longitude without the need for...
PacX Wave Gliders vs. Monterey Bay Buoys
Since the PacX Launch in San Francisco, the Wave Gliders may have only made it to Monterey Bay, but they’ve already circled three NOAA (National Oceanic and Atmospheric Administration) buoys that share their data through their own ERDDAP site.
Spending time circling buoys provides a great opportunity to compare Wave Glider data to the existing standard. Every time the Wave Gliders get near...
Departure delayed
If you look at the recent wave height data you’ll see that 2-3 meters has been pretty common in Monterey Bay these past few days. Far too rough for a boat to go out and make the simple mods we want to make before heading off to Hawaii. If the weather predictions are accurate, Tuesday might work.
Calibration is getting better
Salinity and dissolved oxygen appear to be correct now. They are values that are derived through some ugly math from the values from the CTDO sensor. I’ve regenerated the whole database again from the raw telemetry. As far as I know, all the telemetry values should be right. The only remaining problem is the Datawell MOSE wave sensor, which is accurate but still intermittent. With luck,...
November 2011
5 posts
Datawell MOSE repair
It looks like Friday is the day that we’re going to take a boat out to the PacX gliders to fix the Datawell problem. Until then the data from that sensor will be erratic - the data will be correct, but sparse. The problem is that it has it’s own GPS antenna and it’s having difficulty locking on to satellites, which we suspect is due to the way it’s mounted. Worked great...