projects:hadie
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The payload was spinning for most of the flight causing the signal to fade in and out. Because of this about 5% of image blocks where lost which unfortunately resulted in most of the images being incomplete. Once a block is lost, any subsequent data received for that image is also lost. | The payload was spinning for most of the flight causing the signal to fade in and out. Because of this about 5% of image blocks where lost which unfortunately resulted in most of the images being incomplete. Once a block is lost, any subsequent data received for that image is also lost. | ||
+ | Images from the main and uart cameras can be seen here: http:// | ||
+ | ===== Second Flight ===== | ||
+ | A second flight was made on the 9th January 2011. Using much of the same hardware as the previous flight, its main job was to test the improved SSDV error recovery code. Most of the components survived the last flight and where reused for this one. The main differences where: | ||
+ | * Interrupt driven RTTY code with a single pin and two resistors. (3.3v -> 330 ohm -> NTX2 tx pin <- 2.2k ohm <- rtty output pin) | ||
+ | * The new robust image format, a lost packet will not ruin the rest of the image. See the [[guides: | ||
+ | * Quarter-wave dipole antenna, mounted so that the module doesn' | ||
+ | * Canon A560 camera with CHDK and script to take regular images. | ||
+ | * A new version of the C328 UART camera with a wide-angle lens. | ||
+ | * A thicker polystyrene box with compartments for each of the components, wrapped in foil backed polystyrene sheets. | ||
+ | The balloon was released at 12:17 UTC and began heading east almost immediately. Reception on the small vertical became difficult within about five minutes of release, so we switched to using the stacked yagi array. Even with this the signal was fading fast and the last string to be fully decoded was at 13:09 UTC. There was enough time to receive three full images and fragments of a few more. Contact was re-established by G4FVP and M0DTS at 14:58, almost two hours later! By now the payload was descending and had stopped sending images. The last known position, taken from incomplete telemetry by G4FVP was at 54.383, -2.03966 from about 1300 metres up. The predicted landing spot was 54.3629, -1.88296: | ||
+ | {{: | ||
+ | M0DTS/Rob went to the area but no signal was received. The payload may have been damaged on landing or the hills could have blocking the already weakened signal. I don't know yet what happened to make the signal so weak, but there' | ||
+ | The highest altitude was received by M0DTS from incomplete telemetry, and was 30217 metres at 14:36:09. M0DTS also reported a likely burst at ~14:51 and with a 3.5m/s ascent rate puts the burst altitude at roughly 33.3km. | ||
+ | The flight code for Hadie-2 is available here: http:// | ||
+ | ===== Third Flight ===== | ||
+ | The third flight launched a few months later than planned, on the 4th of June 2011. It recorded a maximum altitude of 31616m at 12:57 BST. This was a repeat of the previous flight with a few improvements: | ||
+ | * A much better 1/4 wave vertical antenna, made with just coax and no solder joints. | ||
+ | * Add a 16-bit checksum to the SSDV packet structure. | ||
+ | * Fixed a trivial bug that caused the baud rate to be slower than expected. | ||
+ | ==== Antenna ==== | ||
- | ===== Second Flight ===== | + | After the massive failure of the antenna in hadie:2 I decided to make this one without any solder joints at all. Only RG58 coax was used, with the outer insulator stripped back just over 1/4 wavelength long and the shield carefully untwisted and split into the four radials. I left the inner conductor and insulator as is, just placing |
- | A second flight is planned for the 10th October 2010. It will largely be a repeat | + | |
- | * Interrupt driven RTTY code with a single pin and two resistors. (3.3v -> 330 ohm -> NTX2 tx pin <- 2.2k ohm <- rtty output pin) | + | The improvement over the last flight was dramatic, |
- | * The new robust image format, a lost packet will not ruin the rest of the image. | + | |
- | * A network of listeners should hopefully reduce | + | |
- | * Quarter-wave dipole antenna, mounted so that the module doesn' | + | |
- | * Canon A560 camera with CHDK and script to take regular images. | + | |
- | The flight code for Hadie-2 is available here: http:// | + | ==== Landing ==== |
+ | |||
+ | We managed to receive telemetry all the way to the ground and after landing. It stopped descending at a surprisingly high 361 metres, which turned out to be because it landed 12 metres up a tree in a small forest on a mountain. | ||
+ | |||
+ | ==== Images ==== | ||
- | Despite | + | All images including |
projects/hadie.1286451319.txt.gz · Last modified: 2010/10/07 11:35 by fsphil