Tags:
create new tag
view all tags
Discussion Forum » General »

Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Telecon tomorrow (Apr. 8 in North America, Apr. 9 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). Progress continues to be made on the new ALTAIR form-factor version of the ORCASat transimpedance amp board, and on electrical characteristics of the photodiode readout -- also some more work done on optical simulation. 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@uvic.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

-- jalbert - 2021-04-08

Hi all,

My apologies for the delay! -- here's an update on recent ALTAIR balloon work, minutes of the last meeting on Mar. 25 (attendees Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 15 minutes(!) from now:

Andrew Macdonald produced a (pre-build) specification sheet for the ALTAIR form-factor version of the ORCASat tramsimpedance amp boards:

and he should have schematics + Gerber files by next week, and will send them out for fabrication the week after. (He has had a bunch of unrelated end-of-fiscal-year bureaucracy to take care of, which explains why his schematics + Gerber files have been a couple weeks slower than I thought they would be.)

We now have a 1/1000 voltage divider for our new PDVS2mini calibrated voltage source (https://www.ianjohnston.com/index.php/onlineshop/handheld-precision-digital-voltage-source-2-mini-detail), using one of these precision matched combined resistors: https://www.digikey.ca/en/products/detail/caddock-electronics-inc/1776-C6815/4360753?s=N4IgTCBcDaIIwHYEDYC0BhZAOOBWVAcgCIgC6AvkA and an ultra-low-offset-voltage op-amp: https://www.digikey.ca/en/products/detail/texas-instruments/TLC2652AIP/277463?s=N4IgTCBcDa4JwDYC0BGAHOpBWJA5AIiALoC%2BQA , so that we can reliably and precisely put 1 uV (or even 500 nV) through our Guildline 1MOhm resistor (when it arrives later this month) to have a very precise 1 pA (and/or even 500 fA) current source for calibrating the TIA boards.

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!

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 very long time; the UK is enduring its second wave of COVID, and with even-more-highly-transmissible COVID variants, and the country is still under a lot of restrictions as a result. Our department electrical engineer Nick Braam sent them another e-mail on Mar. 29 to check up on when they will (finally) be sending the firmware-updated SHX1 modules back to us, to which they still haven't replied. (We'll be sending yet another check-up message later this month.) 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 15 minutes from now -- see below for Skype instructions.

Cheers, talk in 15 mins (!) from now -- thanks all!

justin

-- jalbert - 2021-04-08

DiscussionTopicForm
Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I AttachmentSorted ascending History Action Size Date Who Comment
Unknown file formatodt ALTAIRPDBoardRev2SpecificationDraft2.odt r1 manage 23.2 K 2021-04-08 - 03:43 UnknownUser Pre-build spec sheet for version 2 of the ALTAIR PD transimpedance amp board (draft 2 adds a PD connector that is compatible with the ORCASat USB-mini-B)
Edit | Attach | Watch | Print version | History: r2 < r1 | Backlinks | Raw View | More topic actions
Topic revision: r2 - 2021-04-08 - jalbert
 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback