In attendence: Jared, Charles R, Glenn
Summary: met to discuss the latest to-do lists for the communications team. Important stuff: Update link budget using twiki plugin, what do we do when we look up the rockets wifi null? (see proposed solutions and test below), need to add 2m antenna to new rocket body, V3 patch antennas need to be fabricated, more below...
Link Budget
- Need to put Link Budget onto a spreadsheet
- TWiki spreadsheet plugin decided as best way. Talk of using GNUmeric.
- Need to update the link budget with NW EMC data.
- Charles is going to look into this.
Communication link configurations
- Went over the Launch control, launch tower and telemetry position discussion.
- I believe (from this meeting and the last general meeting) that it has been decided to put the Launch control and telemetry at the same site, a few miles from the launch tower. This would allow for the antenna(s) at telemetry to have the best coverage of the rockets flight path.
- problem what do we do if we end up looking up the rocket's null at/after apogee? This is/could be a problem for the WIFI link.
- Space diversity - have multiple ground antennas, so when one ground station is looking up the null, the other isn't.
- fill antenna - put another antenna on the rocket which would "fill" the null (possible intereference issues).
- PROPOSED TEST - Test the wifi link using the rocket and receive antennas. Setup the wifi telemetry equipment, setup the rocket wifi equipment, turn on the wifi network so the rocket is talking to telemetry, walk/drive a ways off with the rocket and then point the null at the telemetry station and move it around and see what happens.
- Come up with ideas to discuss at next meeting...that means YOU!
2m long wire rocket body antenna
- Used to receive DTMF control tones.
- Need to replicate this antenna on new rocket body
- Get a spare receiver for this antenna (non show-stopper bullet point)
V3 CPA
- Went through Tim's email notes, looked at graph
- had some questions.
- Discuss further with Tim at next meeting.
- need to send off to get fabricated in next couple of weeks.
Additional FM Exciter (non show-stopper)
- 1.2Ghz transmitter converted to run in Ham band, 2.4Ghz+
- Serve as backup transmitter
- Glenn has one, but he needs a different PIC to change the operating frequency.
- Glenn is on this.
Misc.
- Make the test probe lengths on the CPA's equal to a half wavelength, so they are invisible to the VNA.