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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Telecon tomorrow (Sept. 16 in North America, Sept. 17 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). Some important updates on testing (by student Colton Broughton and me) of the four Radiometrix SHX1 144 MHz boards; and from Andrew Macdonald on layout for the new ALTAIR form-factor version of the ORCASat transimpedance amp board (plus the new little clock board). We also have further updates to AIFCOMSS, and progress also continues to be made on optical simulation and on measuring electrical characteristics of the photodiode readout. More discussion items for tomorrow's telecon include: flight/telescope plans and tests; construction and lab tests of the new gondolas/payloads; light sources and light source modelling; goniometric and pre- and post-flight calibration; propulsion work; nanosat bus and payload solid models; computing / website / TWiki forums and e-mails; grant applications; and recap of schedules. I'll send a progress report before the telecon tomorrow.

Here's how to connect:

1) Open Skype on your computer (note that of course, you should first install Skype, http://www.skype.com, on your machine if you haven't already).
2) In the "Contacts" menu, add me ( jalbertuvic ) as a contact, if you haven't already.
3) Just wait for me to Skype-call you at the usual time (5 pm Eastern, 2 pm Pacific, etc).
4) If there is any trouble, or if you don't get a Skype-call for some reason and would like to join, please just send me an e-mail (jalbert@uvicNOSPAMPLEASE.ca).

Here's the tentative agenda:

I) Flight & telescope plans, and upcoming tests
II) Construction, drop tests, and other tests of the new gondola and payload
III) Diffused light source and its modelling, pre- and post-flight calibration, and goniometric calibrations
IV) Solid modelling
V) Computing/website, including recent flight control and simulation progress
VI) Grant applications

Talk to you all tomorrow, thanks!!!

-- jalbert - 2021-09-15

Hi all,

My apologies again for the delay! -- here's the belated update on recent ALTAIR balloon work and minutes of the meeting two weeks ago on Sept. 2 (attendees Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me) -- and BTW I'll send minutes of today's meeting before our next telecon in 4 weeks (see below):

As sent in the earlier message today -- Andrew Macdonald has made a lot more progress on his layout-in-progress of the ALTAIR version of the photodiode readout / transimpedance amplifier board (and on his small separate clock signal distribution board, for producing and distributing the clock signal to the three photodiode readout / transimpedance amplifier boards) -- and a screenshot of his current status is at:

as compared with his screenshot from two weeks ago at:

As you can see, there's a lot more done, and he's almost complete with the design. Hopefully he'll have it fully complete within two weeks, and we'll send it out for production -- and then, of course, he'll populate and test it. As a reminder, the layout is based on the schematic at

Fall co-op student Colton Broughton has been testing the Radiometrix SHX1 144 MHz transceiver modules that were returned to us from Radiometrix (following their firmware update to fix the BUSY output):

and has found some issues with the boards, following that firmware update from Radiometrix. (BTW, I made Colton two extra Arduino-to-SHX1-expansion-header cables to do that testing, since the other two of those cables are in use onboard the ALTAIR payload itself, and in the Capella ground station transceiver box, and I didn't want to take those cables out. The new cables I made are fine.) Of the 12 radio TX to radio RX permutations between those 4 boards, only 3 of the 12 permutations work. 3 of the other permutations give spotty connections (e.g. only around 1 out of every 5 characters gets successfully transmitted -- as if one is transmitting and the other is receiving on neighbouring channels, but not the same channel...), and the remaining 6 permutations do not successfully receive any transmitted characters. We have tried clearing the buffers on the radios, and trying to ensure they are transmitting and receiving on the same channel, but no success yet. One other thing that Colton has found is that the command to produce a square wave test pattern from the board ("GOTEST") does not seem to produce that test pattern on any of the boards (even on the board that appears to successfully receive signals from the other 3 boards). For that, it is as if the firmware update from Radiometrix eliminated that GOTEST command. I will likely need to e-mail Radiometrix to ask about this -- i.e. whether there is a new test pattern command which replaces GOTEST, and (most importantly) why only 3 of the 12 radio communication permutations work, and how can we fix that -- which I will do early next week (assuming, of course, that we haven't fixed these problems by then).

Students Colton Broughton, Sarah Alshamaily, and Will Stokes have completed installing AIFCOMSS ( https://github.com/ProjectALTAIR/AIFCOMSSwithCUPredictorTest ) on their laptops. I've updated AIFCOMSS to work with the recent Cesium v1.83, as well as the instructions, and they all report success with this update and those instructions. The next two things that we know most definitely will need updating (or, rather, creating) are the station-keeping software for AIFCOMSS, and the online command-handling within the onboard Arduino software -- and I'll also be working on those over the next 2 weeks.

We also still need to test out our two 144 MHz Raveon M8S data modem transceivers:

Once we get our 144 MHz transceivers settled and back into the ALTAIR gondola, we'll do some outdoor drop testing of the actual gondola. (We've done all the outdoor drop tests I can think of doing with our dummy gondola.)

And we also still need to test out our new DFRobot SEN0177 payload aerosol monitors that we have here:

I've begun to look some more at MEEP (https://meep.readthedocs.io/en/latest/) for finite-difference time domain (FDTD) simulation of integrating sphere output, but I haven't yet had time to make any significant progress there -- I'm hoping to do that in the next couple of weeks. It will be interesting to compare that with ray tracing simulations, when I can get a chance to do that!

Engineering students Josh Gage and Evan Moore found that the "wings" that Josh had found in the laser diode light output distributions:

were due to how the diode was mounted in the heat sink. When the diode is mounted properly and carefully, the wings go away.

We also have our 10 Hamamatsu S12698-01 photodiodes and 3 Thorlabs FDS100-NOCAN photodiodes (those Thorlabs ones have their windows removed) here in Victoria:

I've given them to Evan to try out -- he's taking a few weeks to ramp up, and will produce some linearity, etc., plots from them soon.

The survey-tripod-mounted device to cross-check yaw-pitch-roll information from the gondola (e.g., on days before/after flights) is also constructed now, thanks to Mark Lenckowski -- photo at:

and all that remains to be done is to finish the small fitting between the device and the bottom of the payload. The purchased hardware in it includes both the survey tripod (http://www.cpotools.com/cst-berger-60-alwi20-o-aluminum-tripod-with-quick-release--orange-/cstn60-alwi20-o,default,pd.html), two adjustable angle mounts (http://www.thorlabs.com/thorproduct.cfm?partnumber=AP180), and a rotation mount (https://www.thorlabs.com/thorproduct.cfm?partnumber=RP01). That last fitting to attach (temporarily, pre-or post-flight) the upper adjustable angle mount to the payload landing gear has been started and will be completed here in the next couple weeks.

We're currently revising the draft initial contractual agreement from our colleagues at Globalstar Canada regarding 2 initial SPOT Trace devices (and their service plans) for the educational side-project for the upcoming NATO SPS application, in which classrooms in elementary and high schools could launch company-donated SPOT Traces using party balloons (or a more environmentally-friendly version thereof), and track them to learn more about winds at different levels in Earth's atmosphere.

Houman will send Cordell and/or us updated sections of his master's thesis soon -- that information will be extremely useful to us going forward. Also, Susana and Nathan, it would be very helpful for us all to get the JHU students' final writeup when you have a chance.

Next grant application will be a NATO "Science for Peace and Security" application (together with Australian colleague partners).

Since two weeks from today will be a holiday here in Canada -- the new National Day for Truth and Reconciliation -- and additionally since all three of Arnold, Liviu and I can't meet in 3 weeks from today, we will skip the next telecon and instead next meet in 4 weeks from today, on Thurs. Oct. 14.

Cheers, and (as mentioned above) the next telecon will be in 4 weeks from today -- thanks all!


-- jalbert - 2021-09-17

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
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PNGpng AndrewMacdonaldALTAIR_TIAPreLayoutImage001_16sep21.png r1 manage 355.5 K 2021-09-16 - 22:46 JustinAlbert ALTAIR TIA board pre-layout (mask from the ALTIUM file, in progress) from Andrew Macdonald, 16 September 2021
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Topic revision: r3 - 2021-09-17 - JustinAlbert
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