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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Telecon tomorrow (Oct. 28 in North America, Oct. 29 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 8 am Eastern Australia). Andrew Macdonald's design of the new ALTAIR form-factor version of the ORCASat transimpedance amp board will be sent out for fabrication this Friday -- and we have some updates on testing of our two Raveon M8S 144 MHz boards (and the four Radiometrix SHX1 144 MHz boards). 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 - 2021-10-28

Hi all,

My apologies for the delay! -- here's the update on recent ALTAIR balloon work, minutes of the meeting four weeks ago on Oct. 14 (attendees Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 12 minutes(!) from now:

First, a separate-from-ALTAIR, but related, announcement -- our pair of MNRAS papers on generation of a laser photometric ratio star (LPRS) have now been published:

Paper I: MNRAS 508, 4399 (2021)


(or, you can find the poorly-formatted journal-published version -- for which Oxford University Press is 100% to blame -- at https://academic.oup.com/mnras/article/508/3/4399/6294488 .)

Paper II: MNRAS 508, 4412 (2021)


(or, you can find the poorly-formatted journal-published version -- for which Oxford University Press is 100% to blame -- at https://academic.oup.com/mnras/article/508/3/4412/6294471 .)

We'd highly recommend reading the arXiv versions, rather than the published journal versions. (Details on that, if you'd like them: Both articles were accepted by MNRAS journal 5 months ago, at the end of May. Then MNRAS's publisher, Oxford University Press, completely messed up the formatting of both articles -- and then absolutely refused to correct their formatting errors prior to their publication! The past 5 months have all been spent in vain trying to get OUP to correct their errors! -- in the end OUP flatly refused to do so, just because it was too much trouble for them -- even though, a couple months ago, OUP had agreed to do so in an e-mail. Anyway ... water under the bridge ... please just read the arXiv versions. smile And, please just let me or my co-authors know anytime if you have any questions on these papers. Happy reading!!!

On to ALTAIR: Andrew Macdonald made some minor improvements to his completed layout of the ALTAIR version of the photodiode readout / transimpedance amplifier board -- specifically: 1) plating the inside of the mounting holes (suggested by Tanner Oleksiuk), 2) adding ground pours around the power traces on layer-3, and 3) widening a few shield-contact areas a little bit. Here's his updated screenshot of his completed layout:

and here's a .zip file containing the full ALTIUM project for the board:

It's (still) ready for fabrication, and will finally be sent out for fab tomorrow -- and we should have the 3 boards next week. Then Andrew will populate and then test these 3 ALTAIR board copies (one for each ALTAIR onboard PD). (And, Andrew will also continue to work on getting the RF shields for the boards fabricated.)

(As a reminder, this board layout is based on the schematic of the completed boards at

.) So, I should have photos of the three fabricated and populated boards (with their master clock board), and hopefully even an initial testing report from Andrew, before the meeting in a couple of weeks!

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.

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 Fall co-op student Colton Broughton 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 5 weeks 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 4 weeks ago, and thus I pinged them 2 weeks ago to follow up -- and they haven't replied to that yet either.

Colton additionally has been testing our two 144 MHz Raveon M8S data modem transceivers:

with a replacement connector cable:


that we purchased. 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 ALTAIR-relevant significant progress there yet -- 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).

Our next telecon is in 12 minutes from now -- see below for Skype instructions.

Cheers, talk in 12 mins (!) from now -- thanks all!


-- jalbert - 2021-10-28

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
Compressed Zip archivezip ALTAIR_PD_2_2021-10-27_1-24-48PM.zip r1 manage 10629.7 K 2021-10-28 - 05:48 JustinAlbert .zip file containing the completed Altium project for the ALTAIR TIA board layout from Andrew Macdonald, 27 October 2021
PNGpng AndrewMacdonaldALTAIR_TIALayoutImage001_27oct21.png r1 manage 421.7 K 2021-10-28 - 05:46 JustinAlbert Completed ALTAIR TIA board layout (mask from the ALTIUM file) from Andrew Macdonald, 27 October 2021
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Topic revision: r3 - 2021-10-28 - JustinAlbert
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