Gee, Peter, you're waaaaay older than I ever would have thought! TEASING!! LOL! Sandy Moore-Furneaux Doctoral Candidate, Department of Communication Co-President, Friends to International Students Public Information Officer, Phi Kappa Phi Area Leaders' Letter Editor & Area Alumnae Representative, La Leche League of Arkansas/Oklahoma ________________________________ From: OU Amateur Radio Club [[log in to unmask]] on behalf of Judson Ahern [[log in to unmask]] Sent: Wednesday, February 10, 2010 12:18 PM To: [log in to unmask] Subject: Re: APRS High-Altitude Balloon Project Peter knows whereof he speaks: He taught your parents to launch them. :-) --- Dr. Judson L. Ahern Professor Emeritus, Geophysics School of Geology & Geophysics University of Oklahoma Norman, OK 73019 [log in to unmask]<mailto:[log in to unmask]> W5JA On Wed, Feb 10, 2010 at 12:04 PM, Peter Laws <[log in to unmask]<mailto:[log in to unmask]>> wrote: Don't forget that there are folks in the building that have been launching balloons since your parents were young ... they can surely help out with the actual balloon part ... Peter On 02/09/10 22:51, Aaron Botnick wrote: Hi All, The OUARC has decided to undertake a project to construct an APRS High-Altitude Balloon, launch, and successfully recover it. Mission tasks include successful tracking via the APRS network for position, speed, altitude, and temperature, along with a possible on-board camera to capture still images at specified intervals. I've pulled the task of coming up with a basic parts list that is, as yet, incomplete. We are soliciting opinions and advice on how to proceed and suggestions on funding sources. I've spec'd several parts from Argent Data Systems, maker of the OpenTracker 1+ and OpenTracker2, I own the OT2m and have nothing but good things to say about it. I propose use of the OT1+ SMT, which is a smaller version of the OT1+ that includes everything except the on-board temperature sensor and DB9 connectors (the headers are on the board), and also includes voltage input from 6-28V with a 5V regulator for GPS power. The ability to run the APRS interface at lower voltages will allow us to use a LiPo battery pack for power. I've also spec'd a low-power 2m transmitter (SRB MX146LV), available from Argent Data, is around 500mw and runs on 5V. For GPS modules, there is a very tiny unit from Trimble that has an aviation (> 30k ft) mode, but runs at 3.3V. We also have the Duelo and ADMS GPSs based on the SiRF Star III module running on 5V. We should be able to get a thermistor and run it on one of the analog inputs (there are 5 on the OT1+), and calibrate the device before launch for conversion of the data later. As for a balloon, we'd like to acquire something akin to the severe weather sounding balloons. The LM335Z temperature sensor is rated at 10mV per Kelvin, and a minimum temperature of -55 ¢ªC, which should take us to nearly 250 mb according to the std atmospheric profile. The whole package needs to be under 4 lbs to be legal, from what we've read. We also need to determine a semi-waterproof box to put the equipment in, a recovery mechanism (ribbon / parachute), and find an inexpensive Canon digital camera capable of running the CHDK firmware to take pictures at specific intervals. Links for reference and prices... CHDK - http://chdk.wikia.com/wiki/CHDK $40 - OT1+ SMT - http://argentdata.com/products/otplus.html https://www.argentdata.com/catalog/product_info.php?cPath=22&products_id=64 $69.50 - SRB MX146LV Transmitter - https://www.argentdata.com/catalog/product_info.php?products_id=134&osCsid=a3d00b3b69a4ffc11c9c99223b0d12be $60 - Duelo GPS SiRF Star III https://www.argentdata.com/catalog/product_info.php?cPath=23&products_id=61&osCsid=a3d00b3b69a4ffc11c9c99223b0d12be $53 - ADS-GM1 GPS SiRF Star III https://www.argentdata.com/catalog/product_info.php?cPath=23&products_id=85&osCsid=a3d00b3b69a4ffc11c9c99223b0d12be $49 - Trimble GPS https://www.argentdata.com/catalog/product_info.php?cPath=23&products_id=95&osCsid=a3d00b3b69a4ffc11c9c99223b0d12be $7 - 8" 2m BNC Antenna https://www.argentdata.com/catalog/product_info.php?products_id=130&osCsid=a3d00b3b69a4ffc11c9c99223b0d12be $0.75 - LM355Z Temperature Sensor https://www.argentdata.com/catalog/product_info.php?products_id=50&osCsid=a3d00b3b69a4ffc11c9c99223b0d12be Thanks for looking this over, and any suggestions you can offer. We certainly aren't the first to do this, a quick google search will show others, but this is a first for our motley crew. 73, de Aaron, WX5AB ([log in to unmask]<mailto:[log in to unmask]>) -- Peter Laws / N5UWY National Weather Center / Network Operations Center University of Oklahoma Information Technology [log in to unmask]<mailto:[log in to unmask]> ----------------------------------------------------------------------- Feedback? Contact my director, Craig Cochell, [log in to unmask]<mailto:[log in to unmask]>. Thank you!