Currently researching the various options for getting the GPS data back to earth. There appears to be several. I'm not really in a position where I can build a board from scratch though if I had the time and patients I would love to give it ago. So more or less one of requirements is a pre-made board.
Checking out several sites, I came across Saskatoon Amateur Radio Club who provided some great information as to some of the gear they had used. They mentioned the OpenTracker which at first glances looks to do what I want and more. Looking further on the same Argent Data Systems site shows several other versions. Hmmmm
The same site also boasts a SRB MX145 Transmitter, which appears to be perfect as an APRS transmitter. Seems a possible solution. I would much prefer loosing an $80-$100 low power transmitter then using a handheld and lose that.
The SARC had also used a Byonics Pocket Tracker which also looked very impressive. What impressed me the most was the built in 2m Transmitter. So with this tracker I would just need to feed in the GPS data. Sadly they don't make them anymore, but have a similar Micro Trak 300 device.
The Micro Trak 300 outputs about 300 mW but I am a little unsure about the frequency I want to operate the APRS on. Should I just use the Australian 145.175Mhz , or pick another digital mode frequency and just collect the data myself. Hmmm Decisions.
Another option I discovered was the Spot Tracker which sends its GPS position via satellite approx every 10 mins. Not exactly what I am after, but as for a recovery tool it could be perfect. Though it may not function about 60000 Ft , it may well survive the final impact and be able to relay its location is the main transmitter fails. A bit of built in redundancy maybe. I also wonder if anyone has modded these to be more suitable for Balloon operation.
Found another tracker - R Trak - which also has a 2m transmitter with changeable frequency. Nice.. It also has Five ADC channels for analog sensor readings which means I may be able to attach some extra stuff.
The search continues
Sunday, September 30, 2012
So many things to think about.
This is my first attempt at a High Altitude Balloon launch so I understand that a lot of research needs to be conducted. I spent most of the evening reading various High Altitude Ballooning project sites and found a wealth of information.
From some initial reading, and I know I will be doing a lot more, I have already discovered a few things. To start with I would need to obtain a balloon, and not just any balloon but one that is capable of withstanding the low pressure experienced at high altitude. As the air pressure reduces the balloon expands causing it to burst. Thus a balloon that has enough stretch and durability to reach the required altitude is needed.
From what I can tell the balloons are designed for different payload weights and altitudes. I will do some more researching to learn more, but I wonder if these balloons can be purchased in Australia or if I will have to purchase from Overseas. Time will tell.
For the recovery of the payload, a parachute will be needed. I haven't done much reading on these yet but they seem to differ in size depending on the payload weight and the required descent speed. Looking at a few HAB video's the chutes look a lot smaller then I would have thought necessary but I guess it really depends on the payload. So something else to learn about.
The payload itself is probably the most important and will take the most amount of time to learn about. I've already seen many different designs and ideas and all of them seem unique in some ways. So far I am already liking the idea of using APRS to assist with the tracking. But I still need to learn about the various options for micro controllers, do I build my own , purchase a pre-made kit , blah blah blah.
I'd love to be able to track the balloon through its entire flight but already this can be a challenge. Mainly for the recovery phase. Whilst aloft the reception of radio signals shouldn't be a problem however once it lands back to earth, (provided it survives the impact) it still needs to be found. So I need to investigate those options. I've seen people use mobile phone SMS to relay the landing location but if the payload lands in an area with no mobile phone service then this will be a problem. Finding a suitable launch site may help here.
I will also need to look into the legal responsibilities with launching such a balloon. Looks like I will need CASA approval to ensure no aircraft are in the projected flight path. This will also relate to the location for launch. I live on the outer burbs of Sydney thus feel I won't be able to launch locally otherwise I will be sure to enter the main flight path of jets into Sydney Airport, drop the payload onto someone's house, or possibly land in the ocean. So looks like a trip outback may be the best option.
I found a website http://habhub.org/predict/ which allows me to predict where a launched balloon may land. I don't know if all the values I entered where correct, but launching a balloon in Bathurst seemed to have me land almost back in Sydney. All will depend on the day I guess, but makes the recovery interesting. As long as the device can relay its landing location I guess it will be like finding a geocache.
Off to do some more research...
From some initial reading, and I know I will be doing a lot more, I have already discovered a few things. To start with I would need to obtain a balloon, and not just any balloon but one that is capable of withstanding the low pressure experienced at high altitude. As the air pressure reduces the balloon expands causing it to burst. Thus a balloon that has enough stretch and durability to reach the required altitude is needed.
From what I can tell the balloons are designed for different payload weights and altitudes. I will do some more researching to learn more, but I wonder if these balloons can be purchased in Australia or if I will have to purchase from Overseas. Time will tell.
For the recovery of the payload, a parachute will be needed. I haven't done much reading on these yet but they seem to differ in size depending on the payload weight and the required descent speed. Looking at a few HAB video's the chutes look a lot smaller then I would have thought necessary but I guess it really depends on the payload. So something else to learn about.
The payload itself is probably the most important and will take the most amount of time to learn about. I've already seen many different designs and ideas and all of them seem unique in some ways. So far I am already liking the idea of using APRS to assist with the tracking. But I still need to learn about the various options for micro controllers, do I build my own , purchase a pre-made kit , blah blah blah.
I'd love to be able to track the balloon through its entire flight but already this can be a challenge. Mainly for the recovery phase. Whilst aloft the reception of radio signals shouldn't be a problem however once it lands back to earth, (provided it survives the impact) it still needs to be found. So I need to investigate those options. I've seen people use mobile phone SMS to relay the landing location but if the payload lands in an area with no mobile phone service then this will be a problem. Finding a suitable launch site may help here.
I will also need to look into the legal responsibilities with launching such a balloon. Looks like I will need CASA approval to ensure no aircraft are in the projected flight path. This will also relate to the location for launch. I live on the outer burbs of Sydney thus feel I won't be able to launch locally otherwise I will be sure to enter the main flight path of jets into Sydney Airport, drop the payload onto someone's house, or possibly land in the ocean. So looks like a trip outback may be the best option.
I found a website http://habhub.org/predict/ which allows me to predict where a launched balloon may land. I don't know if all the values I entered where correct, but launching a balloon in Bathurst seemed to have me land almost back in Sydney. All will depend on the day I guess, but makes the recovery interesting. As long as the device can relay its landing location I guess it will be like finding a geocache.
Off to do some more research...
Saturday, September 29, 2012
Initial Thoughts
This is the start of my project, where I hope to launch a small payload into the higher limits of the atmosphere. Using a high altitude balloon I hope to collect photo's, video and other data along its journey.
After seeing the video of a Lego man reaching the edge of space, I thought it would be a great project to try myself.
I hope to document the project along the way using this blog. At this point I am in the "Wow this sounds cool" phase which always seems to have a thought of success. So fingers crossed.
Below is a link to the Lego Man in space site as well as a news story by CBC The National, which helped inspire me to start my own High Altitude Balloon project.
http://www.legomaninspace.com/
Well off to do some research...
After seeing the video of a Lego man reaching the edge of space, I thought it would be a great project to try myself.
I hope to document the project along the way using this blog. At this point I am in the "Wow this sounds cool" phase which always seems to have a thought of success. So fingers crossed.
Below is a link to the Lego Man in space site as well as a news story by CBC The National, which helped inspire me to start my own High Altitude Balloon project.
http://www.legomaninspace.com/
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