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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Telecon tomorrow (Aug. 29 in North America, Aug. 30 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). More updates on testing of the photodiodes with the new amplifier boards, on telemetry, on the drop-testing pole status, and also some more progress on AIFCOMSS station-keeping prediction/simulation software. More discussion items for tomorrow's telecon include: flight/telescope plans and tests; construction and lab tests of the new gondola/payload; 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 an update with some recent photos, etc, 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


Talk to you all tomorrow, thanks!!!


-- jalbert - 2019-08-28

Hi all!

Apologies for the delay! -- here's a quick update on ALTAIR balloon work over the past 2 weeks, minutes of the meeting 2 weeks ago (attendees Arnold Gaertner [NRC] and me), and a reminder of the telecon in two hours(!) from now:

Student Peter Ogilvie did a set of very useful new linearity tests on the OSI UV-015 photodiodes (as usual comparing them with a Thorlabs FDS100 photodiode) now using a blue (405 nm) laser diode light source in addition to the red (660 nm) source that he had been using previously. Here are his new plots (done both with and without 5V reverse biasing):

His plots still show the worrying non-linearity of the OSI UV-015 output, with either 660 nm or 405 nm incident light. (The 660 nm actually looks slightly better than the 405 nm in those plots -- and both look somewhat better than the even larger non-linearity seen in earlier tests, in both Peter's and Andrew Macdonald's earlier plots [with 660 nm incident light]:

Peter's earlier OSI UV-015 linearity plot:

Andrew's earlier OSI UV-015 linearity plot:

-- but although the OSI UV-015 non-linearity now seems somewhat smaller in Peter's new plots, it certainly hasn't "gone away" by any means, so the OSI UV-015 is clearly still quite problematic). I'm still in the process of getting a quote for windowless Hamamatsu S12698-01 photodiodes, which could serve us as an alternative to OSI UV-015 PDs -- I'll hopefully have that quote from Hamamatsu in the next couple of days. In any case our next step here, testing-wise, is clearly for us to test the windowless Hamamatsu S2386-8K photodiodes that we presently have. We have been waiting for the class 100 laminar flow clean box to arrive in order to do that testing of our windowless photodiodes. That clean box should arrive here this coming month, and Peter Ogilvie will get back to campus on Sept. 5, so Peter will do that testing of our windowless photodiodes soon.

The integration of the SHX1-144 144 MHz telemetry with the present ALTAIR telemetry (that uses the DNT900 [910 MHz] as default and RFM23BP [440 MHz] as the single backup) is still ongoing -- I've found a difference in the main onboard Arduino Mega 2560 control board, with the control board that is in the Capella ground station, in how they process busy signals from SHX1-144 boards -- the ground station control board appears to do the "right" thing, whereas the onboard control board is hanging up when it gets a busy signal from an SHX1-144, so I'm in the process of debugging why that occurs (and hopefully avoiding having to entirely open up the payload and completely remove the onboard main control board, which is a major operation). I'm hoping to have that fully debugged and working before I fly out of town on Sept. 7 (to CERN and meetings in Chicago and Boston -- I return to Victoria on Sept. 28).

On Aug. 20 we delivered a notification to the local municipality (Saanich, the Victoria suburb in which both my backyard and half of the UVic campus are located) regarding outdoor drop testing in my backyard, which has been bureaucratically held up because of the local height restriction bylaw issues mentioned in previous minutes ( https://wiki.heprc.uvic.ca/twiki/bin/view/Forum/ForumGeneral0032 ). Assuming that Saanich does not reply negatively by Sept. 3 (i.e., two weeks after our notification), we will be able to resume drop testing in my backyard on that date (next week!).

I'm also working with student Zejia Xu on the actual station-keeping algorithm for AIFCOMSS. Presently the "station keeping" code in AIFCOMSS just turns on the propellers in the simulation at full power, and propels the gondola in a single direction until the battery runs out (it's presently most certainly not actual "station keeping"). We're developing some actual station keeping algorithms and will implement them in the code.

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 applications will be a new CSA FAST (due Oct. 18), a "New Frontiers in Research Fund" (NFRF -- LoI due Sept. 4, then application due Dec. 10), and a NATO "Science for Peace and Security" application, together with Australian colleague partners.

Our next telecon is in two hours from now (see below for Skype instructions).

Cheers, talk in two hours from now! -- thanks all!


-- jalbert - 2019-08-29

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng FDS100PhotodiodeResponseWithAndWithoutAppliedBias_405nm.png r1 manage 24.6 K 2019-08-28 - 22:49 UnknownUser Plot from Peter Ogilvie's photodiode comparison test on 20 Aug 2019.
PNGpng FDS100PhotodiodeResponseWithAndWithoutAppliedBias_660nm.png r1 manage 29.0 K 2019-08-28 - 22:49 UnknownUser Plot from Peter Ogilvie's photodiode comparison test on 20 Aug 2019.
PNGpng UV-015PhotodiodeResponseWithAndWithoutAppliedBias_405nm.png r1 manage 26.5 K 2019-08-28 - 22:50 UnknownUser Plot from Peter Ogilvie's photodiode comparison test on 20 Aug 2019.
PNGpng UV-015PhotodiodeResponseWithAndWithoutAppliedBias_660nm.png r1 manage 27.1 K 2019-08-28 - 22:50 UnknownUser Plot from Peter Ogilvie's photodiode comparison test on 20 Aug 2019.
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Topic revision: r3 - 2019-08-29 - jalbert
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