Launch Day Plans:
-current plan is for Tuesday May 29 - this could change, depending on weather.
-launch location is a 2 hour drive north from London near Orchardville (location constrained by aircraft flight vectors)
-predicted launch time is between 11:00 and 13:00
-latest path forecast is below. We'll have more accurate forecasts near launch date / time
-chase vehicle 1:
-driven by Doug Elliott VA3DAE
-supports direct reception of APRS beacon on 144.39 MHz, and Internet tracking via APRS.fi over date enabled cell phone
-mave be beaconing chase vehicle position with call sign VA3DAE-2, graphic symbol = van
-expected to have one additional Ham operator, and multiple UWO staff as passengers
-van is a Honda Odyssey: driver plus 5 to 7 passengers
-will be at launch site at or before 11:00, and will follow balloon after launch
-chase vehicle 2:
-driven by Dave McCarter VE3GSO
-supports direct reception of beacon on 434.03 MHz via transportable helical antenna mounted on a tripod
-will not attend launch - will pre-position in the predicted landing area
-additional chase vehicles
-anyone who can view the APRS.fi website on a cell phone with data plan can follow the balloon and help find it
-additional chase vehicles should register at launch site to receive communications instructions
-expected flight duration: 3 to 4 hours
-expected APRS tracker battery life: 1.5 days, giving us transmission until about midnight Wednesday if landing doesn't disable antenna
|---- Topic ----||---- Discussion ----|
|Radio signal strength / propagation||Dave did some calculations, with
assumptions, and believes we're OK with the UHF radio. (The VHF radio outputs 1.0 watt,
Assuming a full 10mW UHF output, a minimal 1dB loss to the antenna, 3dBi of transmit gain (should be more like 5 dBi), a free space path loss of 102dB (40km line of sight at 434MHz), a receive antenna gain of 12dBi, and a 1.5dB loss in a length of coax to the Ft-817(ground radio receiver), the received signal should be near enough to 20 microvolts, or S7, a nice strong signal, 20dB or more S/N.
|Maximum acceleration||GPS specs say maximum is 4G, some references warn to expect up to 8G on balloon burst. Some team's photos seem to show simple shock absorbers in support lines|
|RaspPi software to generate the APRS signalling, and something needed on ground to interpret it, and generate map references||Xastir being considered for the payload RaspPi, (http://xastir.org/index.php/Main_Page) and Alexis is already testing it. FLdigi is proposed for the ground receivers - https://sourceforge.net/projects/fldigi/|
|Some GPS units have altitude limitations, and Byonics sells one specifically for HAB applications||The specs for the GPS UWO is using are 50,000 meters, and up to 4G acceleration. See "maximum acceleration" topic higher up in this table. The Byonics HAB GPS is good to 270,000 feet = 84,000 meters.|
|Payload Retrieval||One teams log noted that landing damage and/or
awkward orientation may prevent further radio transmissions. They recommended using SPOT
satellite location service. Location options:
-hope transmitter keeps working and be ready to do Radio Direction Finding (RDF)
-depend on last GPS transmission. readings are within 2.5 meters, offset by drift between last transmission and landing - up to 60 seconds
-change to a different antenna after, or just before touchdown?
-have a second hardened radio/antenna that's activated just before touchdown?
-generate an audio tone of some sort that can be heard by searchers?
|Including data in APRS messages||APRS messages can contain what ever data you want (subject to about a 40 character length limitation) in addition to lat, long and alt. Might be able to do some data compression and get most of data transmitted in real time, at once a minute interval of APRS beacons.|
|double tracking systems||Doug Elliott has purchased and will make available
a specialized HAM APRS tracking system for HAB applications that includes
-a 1 watt Radio that transmits on the standard Ham frequency,
-a 37 inch dipole antenna,
-a GPS selected for high altitude compatibility, and
-a controller to connect everything together ("TinyTrak 3") .
Alexis would like to proceed with development of UHF based tracking, but use Ham APRS system as a fallback, or parallel system. Details on the "MT-1000 HA Combo" near the bottom of this Byonics page.
|Batteries||Many HAB teams use specific AA batteries with
reduced weight and better tolerance of cold weather. From Byonics:
|Timeline||I'd be glad to leave the project management stuff of my pre-retirement days behind me, but I think it would be helpful to have a rough and tentative schedule, especially for items that have a long leadtime. Hmm. That probably warrants another section in this webpage - I'm on it.|
|Things to be careful with||-handling latex balloon only with gloves on (Some
websites say this isn't actually needed.)
-starting radio transmitters only if antennas or dummy loads connected
-helium safety procedures
-crowd control at launch site: cordon off launch area & have safety officer?
-chase vehicle drivers distracted by radios, cell phones, laptops
|Water Landing Possibility||There are a lot of lakes, rivers, swamps, etc in
Southern Ontario that our payload could end up in.
-should Doug put his canoe on top of his chase vehicle (An Odyssey van) just in case?
-will the payload be waterproof, avoiding damage that might prevent recovery of data
-will the payload float indefinitely on the surface of a lake, or will it sink soon?
|Chase vehicle personnel||I'm watching European balloons that have sustained ground speeds of 20 to 40 km/hour. Our chase vehicles, being constrained to roads, will likely have to travel twice as far, or twice as fast. This makes me think it's probably mandatory from a safety point of view to have at least 2 people in each chase vehicle, so the driver can concentrate on driving, and navigating.|
|Chase Coordination||The hams will probably want to co-ordinate chase
operations using VHF radios.
-Should we use SORT repeaters, simplex...?
-Should we try to have a ham in each chase vehicle?
-Should we have someone act as net control, co-ordinating chase vehicles and sending out text message updates to a distribution list frequently?
-should we have a contact information sheet (started below) that has, for all locations and vehicles
-names of all people expected
-cell phone numbers
-ham radio facitities
-vehicle license plate
-chase gear present
-radio receiver > mapper for 434.6 MHz
-radio receiver > mapper for 144.39
-Internet browsing ability for APRS.fi map
|Zeroing in on payload||-trackers may still be transmitting after payload
lands - should we be ready to use fox hunt / radio direction finding techniques?
-will the short burst nature of APRS transmissions make it difficult to take bearings.
-need to have compass, protractors, parallel rulers and paper maps ready if we want to try this
-possible future electronics/readio project: capture bearings on short APRS transmissions, and correlate to decoded call sign
|What to do when darkness falls?||-predetermined meeting place? Probably have to ad
lib, depending on balloon path
-do we have a contingency to continue searching on the morning after launch
|Standardize map||Should we all be using a common map and grid scheme
for identifying locations?
-we'll mostly be using electronic mapping, and different ones in different software tools
-suggest standard way of identifying locations using:
-local place names, like "heading north of Stratford on highway 123"
-decimal lat/long, like: my last GPS report was 40.21 degrees North, 80.73 degrees West
|Launch Date||-Tentative date of Sunday May 27 was scrubbed due
to possible thundershowers
-current planned launch date is Tuesday May 29. Location? Arrival time? Is launch site secured for safety?
|Expected Flight duration: 3 - 4 hours
-about 1.5 - 2 hours ascent,
-about 1.5 - 2 hours descent
(work in progress)
|"Location"||Person||Car License||Ham Callsign||Cell Phone / Text||434.6 MHz mapper||144.39 MHz Mapper||APRS.fi mapper||Fox Hunt / RDF|
|Launch Point only||UWO Person 1 ?|
|UWO Person 2 ?|
|Chase-1||Doug Elliott - driver||VA3DAE||VA3DAE||519-630-8925||no||yes||yes||yes-144.39|
|Tom Pillon - shotgun||VE3HOR|
|Chase-2||Dave McCarter||VE3GSO||VE3GSO||519-319-1437||yes||no||yes||yes-144.39 ?|
|Shotgun - UWO ?|
|Chase-3 ?||Alexis Pascual - UWO||xxx.111||519-xxx-yyyy||no||no||yes||no|
|Chase-4 >||UWO person?||yyy.222||519-aaa-bbb||no||no||yes||no|
|--- Date ---||--- Milestone ---||
--- Responsible ---
|done||Development complete on 434.6 MHz payload transmitter|
|Development complete on 434.6 MHz ground receiver, decoder and map generator|
|End-to-end testing complete on 434.6 MHz tracking system|
|done||End-to-end testing complete on 144.39 MHz tracking system|
|done||Go/nogo decision on inclusion of 434.6 MHz tracking system - it's in|
|done||Go/nogo decision on inclusion of 144.39 MHz tracking system - it's in|
|done||Testing complete on payload sensors and data acquisition|
|done||Construction, integration, packaging and testing of payload electronics|
|done||Construction and testing of payload container and connection cords.|
|Testing complete on parachute deployment system|
|done||Chase vehicle plan decided and documented|
|Chase vehicle equipment tested|
|Chase rehearsal completed?|
|Tethered test flight completed?|
|done||Launch date and location finalized. It's never final, but May 29 is current target. Location is near Orchardville|
|Launch day safety plan developed, and documented|
|Launch day safety plan reviewed.|
|Launch day time line decided and documented - tentatively Tuesday May 29|
|done||Launch approvals and notifications prepared|
|done||Launch approvals and notifications reviewed|
|done||Launch approvals and notifications submitted. Still need launch day communications with NavCan.|
|done||Helium tank ordered|
|done||Helium tank picked up|
|Launch day materials gathered and pre-packed|
|Publication of data extracted from recovered payload,|
|Publication of flight data extracted from APRS.fi||Elliott|
|Publication of data analysis|
|Publication of Mission Summary|
|Formulation and publication of future HAB plans|
|Done?||Due Date||For Whom||Description|
|May 26||Elliott||document Laptop receiver/mapper set up for McCarter|
|y||Elliott||waterproof APRS tracker & document installation requirements|
|y||Elliott||deliver APRS tracker to Alexis for inclusion in payload|
|y||Alexis||Publish Launch time and location|
|y||Alexis||Publish chase vehicle strategy - are we recruiting ASAP?|
|Alexis||Publish chase vehicle coordination communications strategy|
|y||Alexis||Publish predicted flight path twice daily and/or method to generate it|
|Elliott||Get independent APRS tracker working in van?|
|May 27||Alexis||Publish procedure to be followed when payload is found|
|Alexis||Publish procedure to be followed if payload not located by darkness on May 29|
|May 29||Elliott||Test APRS tracker at launch site|
|McCarter||preposition chase vehicle (ideally with assistant) near predicted landing point|
|Alexis||Communicate actual launch time|
|Chasers||Find the payload, & return it to London untouched (unless it has water inside?)|
|Elliott||Download beacon history from APRS.fi|