Here are minutes of our meeting on Thursday -- please just reply with (or let me know) any corrections -- thanks!:
Attendees: Arnold Gaertner (NRC), Susana Deustua (STScI), and Cordell Grant & Houman Hakima (UTIAS-SFL).
Firstly our congratulations to Houman, who is graduating with his MASc in Engineering from the University of Toronto, via its Space Flight Lab, this coming week, after his production of the initial design for the ALTAIR nanosatellite (amongst other things as well)! Houman will be continuing on at UTIAS-SFL to work on robotics projects. Thanks also to Cordell for supervising the work. Congratulations to Houman!!!
Yorke was in "radio-free New Hampshire" on Thursday (he returned to Hanover on Friday) and thus was unable to join this time, but is back in town now. Final integration of the gondola still needs to be done (Yorke sees no obstacles). There are some software and firmware improvements that Yorke would still like to make. Yorke would also like to complete another in-the-lab optical calibration run with the instrument rise time problem solved. We still need to develop the flight procedures book. I'll be getting to Hanover the day after tomorrow, and the weather forecast is variable for the next week or so -- we'll try to get in a flight when we can. Outdoor operations-wise, we'll additionally try to do another pre-flight, long-range check of radio transmission (to Gile Mtn. or Mt. Ascutney), and also do some observations of stellar standards to further check the throughput of the telescope and camera.
Marlene has posted the optical transmission test data on the 10 km path from Mt. Tolmie to Observatory Hill that we took on June 5, and she has analyzed the data and found that there appears to be no significant atmospheric scintillation at frequencies above approximately 8 kHz. Thus, for possible backup and/or ultra-long-range communication with the payload, we could perhaps in the future encode information in the pulsing of the laser at frequencies from, e.g. 50 to 100 kHz, and separate that information from atmospheric scintillation via the electro-optical analogue of a high-pass filter. Marlene is now calculating the optimal divergence of the laser, as there can be thought of as being effectively two terms in the atmospheric scintillation, the first due to time-dependent angular diffraction of the collimated laser beam, and the second containing both time-dependent divergence angle changes in the beam and collimation-independent, time-dependent dimming of the laser light (such as the scintillation/twinkling we see in stars). A theoretical laser beam with zero divergence has zero chance of ever exactly hitting its target due to the first of these two terms, but an isotropic source is too dim to be easily observed above background at long distances; thus there is an optimal divergence somewhere between "zero" and 4pi steradians, and Marlene is now working on calculating that (using Tatarski and Fried).
As hinted above, Houman will send the latest design for the baffle and LED mounting, and his master's thesis itself -- in amongst his graduation preparations.
Susana is missing the JHU students, but has started the process to set up some lab space in STScI in July to continue their work. She also is hoping to come up to Hanover to visit Yorke and me at some point in July, and we could touch base on instrumentation, and possibly do a flight or two together.
The projectaltair.org website may be moving to a new physical computer host in a few weeks, in the process of fixing its issues such as file upload problems. In the best of all worlds, such a move should be invisible to anyone using or accessing the site, however my guess is it is unlikely we'd be in that corner of the multiverse. I'll work on keeping people updated in any case. We've also purchased some low-cost equipment for starting to test out having a bit of propulsion on the gondolas, which is largely a topic for after we start to get some science, but still fun to start to play with on off-hours.
That's all I remember, please send things that I forgot. Next telecon in 2 weeks, on Thursday, July 2 at 1:30 pm Eastern time.
cheers, thanks all! justin
On Thu, 18 Jun 2015 02:32:27 GMT, Justin Albert wrote:
> Hi! > > Telecon tomorrow (June 18) at our usual time: 1:30 pm Eastern (10:30 am > Pacific, 19.30 European). Discussion items include: flight plans, light > sources and light source modelling, goniometric and pre- and post-flight > calibration, communications tests, new nanosat bus and payload solid > models, computing/website, grant applications, and recap of schedules. A > reminder of the CSA project timeline is attached. It may be a brief > meeting again as Yorke is currently in "radio-free New Hampshire" and > will miss this telecon (but will be back in Hanover on Friday). > > 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 (1:30 pm Eastern, 10:30 am Pacific). > 4) If there is any trouble, or if you don't get a call for some reason and would like to join, just send me an e-mail (jalbert@uvic.ca). > > Here's the tentative agenda: > > I) Flight plans > II) New diffused light source and its modelling, pre- and post-flight calibration, and goniometric calibrations > III) Communications tests (possible backup optical and radio, etc) > IV) New nanosat solid models from Houman and Cordell > V) Computing/website > VI) Grant applications > VII) AOB > > Talk to you all tomorrow, thanks! > justin > > Attachments: > http://projectaltair.org/HyperNews/get/AUX/2012/11/12/18.02-43361-Schedule-20120702_hqp.pdf >