Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all!

Telecon tomorrow (Apr. 7 in North America, Apr. 8 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). We now have some data from the TIA frontend of the ALTAIR photodiode readout / transimpedance amplifier boards from Andrew Macdonald (and he's presently working on also getting data from the ADC on the board). I have some more new results on simulation of integrating sphere output using MEEP (https://meep.readthedocs.io/en/latest/), and also some more progress has been made with operation of the two Raveon M8S 144 MHz transceiver boards. 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 the progress report and plots 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
VII) AOB

Talk to you all tomorrow, thanks!!!
justin

-- Justin Albert - 2022-04-07

Hi all,

My apologies for the delay! -- here's the update on recent ALTAIR balloon work, minutes of the meeting 2 weeks ago on Mar. 24 (attendees Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 20 minutes(!) from now:

Andrew Macdonald has continued to make progress over the past couple of weeks with our three fabricated ALTAIR photodiode readout / transimpedance amplifier (TIA) boards (and their clock generation/distribution mini-board), and is presently working with his new setup to obtain data from the TIA front end of the boards:

(and he'll get data from the ADC using his Arduino and new firmware shortly thereafter).

I've done more work on MEEP (https://meep.readthedocs.io/en/latest/) finite-difference time domain (FDTD) simulation of integrating sphere output. I realized that the MEEP "GaussianSource" input that we had been using was completely the wrong way to input the beam (by definition, GaussianSource is a pulsed beam source, rather than a CW beam source), and switched to MEEP "GaussianBeamSource" input (which is the CW Gaussian beam that we prefer as input). One can compare the following animated GIF (with GaussianBeamSource input):

to this previous animated GIF (with GaussianSource input):

The brief list of remaining simple needed updates to the simulation are 1) Eliminate the spurious initial transient (that one can see at the beginning of the first animation), 2) Add surface "roughness" to the sphere to better mimic a true integrating sphere (presently, the simulated surface is just a pure shiny aluminum surface!), 3) Plot the far-field output distribution that we actually care about, and 4) Try some additional hacks on my list to get around the fact that we can only simulate a tiny (8 um diameter!) sphere, instead of the 2" spheres that we use in real life.

The two 144 MHz Raveon M8S data modem transceivers are still here in my office (together with the LiPoly batteries that power them), and hopefully this weekend I will get a chance to test Colton Broughton's most recent code updates for them, which can be found in:

https://particle.phys.uvic.ca/~jalbert/ALTAIR_M8S_Colton8dec21/

(as compared with his older code within https://particle.phys.uvic.ca/~jalbert/ALTAIR_M8S_Colton17nov21/ ).

Colton Broughton, Sarah Alshamaily, and Will Stokes have also 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.

Regarding the latest news on our four Radiometrix SHX1 144 MHz transceiver modules that were returned to us from Radiometrix (following their firmware update to fix the BUSY output):

and the problems that Colton found with them (i.e., that 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 sent an e-mail to Radiometrix to ask about this about 6 months ago. They then sent back an e-mail a week later asking for more information, and Colton replied to them the next day providing the info (just a query about what logic voltages we were using -- we've being using 5V TTL from our Arduino Megas). Radiometrix has not replied to us since that e-mail reply sent to them 26 weeks ago, and thus I pinged them 24 weeks ago to follow up, and again 19 weeks ago -- and Radiometrix hasn't replied to those yet either. I will be pinging Radiometrix on this yet again next week.

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

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).

Our next telecon is in 20 minutes from now! -- see below for Skype instructions.

Cheers, talk in 20 mins (!) from now -- thanks all!

justin

-- Justin Albert - 2022-04-07