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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Welcome to the utopia of 2021, where all of the world's problems in 2020 have vanished....
First ALTAIR telecon of 2021 tomorrow (Jan. 14 in North America, Jan. 15 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, noon Hawaii, 23.00 European, 9 am Eastern Australia). Evan, together with new student Michael, are testing our new boards (i.e., the transimpedance amps and motherboards) with the Keithley 2450 (as well as with Evan's previous hardware tests), and also with new firmware code, and things are looking good so far. I've done more work on ray tracing and FDTD Monte Carlo simulation (and have some new plots on that, which I'll send around tomorrow). We additionally have recent updates on AIFCOMSS, and on the 144 MHz transceivers (Raveon and Radiometrix). 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 - 2021-01-14

Hi all,

My apologies for the delay! -- here's an update on recent ALTAIR balloon work, minutes of the last meeting of 2020 on Dec. 17 (attendees Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 10 minutes(!!!) from now:

We now have the new Keithley 2450 source-measure unit (it arrived last week on Jan. 4) -- here's just a test video of it measuring a voltage as a function of time:

and our electrical engineer Evan Moore, together with our new electrical engineering student Michael Huynh, is now using it to test our new updated transimpedance amplifier (TIA) boards that we got back from the fabricator (and Evan then populated) in early December. Here are photos of that populated TIA, together with an ORCASat motherboard (and the Thorlabs laser diode drivers that we use for ORCASat):

Evan and Michael are testing carefully for any current leakage etc. -- Evan's carefully-designed guard trace and guard plane around and below the photodiode anode signal trace should definitely prevent that! -- and also measuring the linearity of the photocurrent amplification etc. We are also presently getting quotes on a 1 MOhm calibrated resistor (also to aid in testing and cross-checks).

I've done some more work on ray tracing Monte Carlo simulation, and am using the ROBAST (https://robast.github.io) open source ray tracing package. Here are some renderings of light input into an integrating sphere from that:

Radiometrix still has our four SHX1-144 transceiver modules (they arrived there on Apr. 6) and is doing their firmware update that solves the BUSY output issue. They'll then test them out and send them back to us. Due to the COVID-19 situation in the UK, they've been taking a long time; the UK is enduring its second wave of COVID, and the country is still under a lot of restrictions as a result. Our department electrical engineer Nick Braam has sent them (a few weeks ago, on Monday, Dec. 14) an e-mail to check up on when they will (finally) be sending the firmware-updated SHX1 modules back to us. In the meantime, we've also been doing more connecting up and testing out of our two new 144 MHz Raveon M8S data modem transceivers here in Victoria:

After checking them out with Raveon's Windows-based Radio Manager software, I've started to connect the radios up to Arduino Megas -- in the next few weeks I'm planning to get them talking to one another, and then I'll check out their effective ranges.

Once we get those 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:

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 10 minutes (!) from now -- see below for Skype instructions.

Cheers, talk in 10 mins (!!!) from now -- thanks all!


-- jalbert - 2021-01-22

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng IntegratingSphereCutawayWithSingleYellowLightRay.png r1 manage 135.2 K 2021-01-14 - 22:23 JustinAlbert ROBAST ray trace of an integrating sphere cutaway with a single light ray
PNGpng IntegratingSphereWireframeWithSingleYellowLightRay.png r1 manage 114.6 K 2021-01-14 - 22:23 JustinAlbert ROBAST ray trace of an integrating sphere (wireframe view) with a single light ray
PNGpng IntegratingSphereWith100000Rays.png r1 manage 148.0 K 2021-01-14 - 22:25 JustinAlbert ROBAST ray trace of an integrating sphere with 100000 light rays
PNGpng IntegratingSphereWithYellowLightRays.png r1 manage 85.6 K 2021-01-14 - 22:24 JustinAlbert ROBAST ray trace of an integrating sphere with 100 light rays
Quicktime moviemov Keithley2450MeasuringAVoltageVideo.MOV r1 manage 1791.2 K 2021-01-14 - 22:34 JustinAlbert Video (taken 4 Jan 2021) of the new Keithley 2450 measuring a voltage as a function of time
JPEGjpg ORCASatTIAPlusMotherboard20201218_175422.jpg r1 manage 902.2 K 2021-01-14 - 22:32 JustinAlbert ORCASat TIA plus motherboard and laser diode drivers photo 18 Dec. 2020
JPEGjpg ORCASatTIAPlusMotherboard20201218_175442rot.jpg r1 manage 1024.4 K 2021-01-14 - 22:30 JustinAlbert ORCASat TIA plus motherboard and laser diode drivers photo 18 Dec. 2020
JPEGjpg ORCASatTIAPlusMotherboard20201218_175455.jpg r1 manage 326.7 K 2021-01-14 - 22:31 JustinAlbert ORCASat TIA plus motherboard and laser diode drivers photo 18 Dec. 2020
PNGpng rayAngleWRTSphereNadir100000Rays.png r1 manage 36.2 K 2021-01-14 - 22:27 JustinAlbert Plot of the ray angle with respect to the sphere nadir with 100000 rays
PNGpng rayAngleWRTSphereNadir1000Rays.png r1 manage 28.8 K 2021-01-14 - 22:26 JustinAlbert Plot of the ray angle with respect to the sphere nadir with 1000 rays
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Topic revision: r3 - 2021-01-22 - JustinAlbert
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