With this launch, we have made a image livestream, sending the largest, highest, fastest images ever sent in realtime from the stratosphere by amateurs, with 10mW of radio power – as much as a single LED. We had two payloads attached to a weather balloon, and reached 36km altitude. We sent out and received live images as it was flying, plus GPS information, that everyone could receive and automatically post online for everyone to see – in real time!
All scripts, PCB designs, etc, are all available for you under a creative commons licence. I’ll be posting those later.
Feel free to leave a comment below, providing some feedback, e.g. stating what we can do better next launch, what sensors you would like to see in them, etc!
|Cost||€150 (just helium+balloon)|
|Launch||12:36 (11-09-2011 Delft Netherlands)|
|Touchdown||15:00 (11-09-2011 Heereveen Friesland)|
|Max. Altitude||35.748 m (#28 arhab record)|
|# Pictures Taken||1731 Pictures|
|# Pictures Sent Live||123 Pictures|
|# Pictures Received Live||119 Pictures|
|# Data Received Live||6.000.000 bits|
|# Max Data Rate||1.200 bits/s|
|Largest image sent live||800×592 px (#1 record)|
|3D Distance Traveled||205 km|
|Minimum inside temp||+5°C|
|Radio Power||10mW (434.653MHz, 8n2)|
Some Live images we received
We received 5.632.000 bits correctly for our images. These were 119 images that were sent over that we all received almost all entirely. Here is my pic of three images that sum it up.
3D Stereo roundshot of the Payloads
Retrieving the Payload
What was in the Main Payload?
What was in the Backup Payload?
So how do we send and receive stuff live?
You will learn by watching this video:
1700 images taken, 123 images sent
Sending an image took between 10seconds and 60 seconds. Within the time of sending an image, the webcam had taken much more. So, which one should it send next? The latest? No. Logically it would be, the prettiest or the best. So i made a simple algorithm that chooses the best image from two factors: (1) a mean grey value (2) a 8-bit standard deviation of ideally 30, so, not too much deviation in the image, but also not too little. You can read all about that algorithm in my post here.
Some Other Data
In my other post, i talk about the subparts of this module.
Here you can read about the Battery Module i designed
Here you can read about the GPS module i designed
Here you can read how to build this proper antenna yourself
Here you can read how to make a high-altitude cutdown mechanism
Information on the Backup Payload on Space Camera Live 1
Information about the Main Payload on Space Camera Live 1
Phillip Heron, for inventing SSDV we use for image transfer and image hosting. Daniela & Mathijs, at mission control. Special thanks to: Wouter Weggelaar [PA3WEG] & Eric de Jong for valuable tracking and recovering. Made possible by: Jacco Hoekstra, Michel Badoux & Jan Siebring from TU Delft Aerospace faculty. Onno for driving. Pictura for the car rental. All members of UKHAS.