In the search for non-evading targets like the Cessna N2700Q there are many solutions. I'd like to highlight one potential capability: A high altitude balloon with a high end digital but low cost camera (with 12 X or more optical focus, we used a Canon S3 IS camera). The idea is that you want to look at a large swath of land and have enough resolution in near real time. This is what we did for GeoCam but with a NASA balloon and many other experiments (HASP). However a homemade balloon is not really hard to do (most of these homemade projects generally aim at getting an edge-of-space picture so there is no good pictures of the ground, especially using the best optical focus). The flyover of a homemade balloon is about 2-3 hours and reach about the same height as a NASA balloon. Because of the shorter time up, the distance covered is less as can be seen in their map. The big issue is to make sure there is a "robotic" platform akin to what people use to do panoramas or Kite Aerial photography. CMU-Google have designed a system called Gigapan, but I am not sure it can be used directly on a small balloon with restricted power issues. Maybe a system like this one might be interesting to investigate.
On GeoCam, we basically used a microcontroller that sent a signal to what we called a finger to push the button on the camera. When powered up, we also had to have a system to get the optical focus to be at a maximum. Results can be seen here. Once shot, one of the issue is making sure that the data then becomes available to a large public. This is not trivial when these panoramas take about 2-4 GB. It is reasonable to cut them into smaller panoramas. Smaller panoramas could be as small as this one or as large as this one. One of the issue is clouds as can be seen here. In our case, timing because photos shots was about 23 seconds with a 4 GB SD card. In our second flight, we looked for a 80 second increments with an 8 GB SD card. The second time increment was designed to take advantage of the 20 hours of flight. One of the interesting element, if the flight is to be short, would be to reduce the time increment in order to allow for the camera to swing and take photos sideways. This also requires another RC-motor and a mechanism to allow for the swinging mechanism. When the balloon lands, it is a matter of putting the card into a computer with Autopano which automatically puts these images together into panoramas. Using a software like Zoomify to put these panoramas on the web is essential to reduce the bandwidth between the server and people helping the search. On a side note, both Zoomify and Autopano were supported by very cool team of people.
We eventually did an an assessment of the resolution of the results and it turns out that we have about a 1 meter resolution. Please note that the panoramas such as this one used images with 50 percent lower resolution (that was due to an earlier version of autopano that has since been fixed). Also, in order have an idea of the size of an airplane, we picked two jets during the GeoCam flight. While the low resolution image on this entry is small, the larger image, makes it a non trivial image. The human eye is clearly able to make up this is a plane. This jet is also most probably larger than a Cessna. Some assembly pictures of GeoCam can be found here.
On GeoCam, we basically used a microcontroller that sent a signal to what we called a finger to push the button on the camera. When powered up, we also had to have a system to get the optical focus to be at a maximum. Results can be seen here. Once shot, one of the issue is making sure that the data then becomes available to a large public. This is not trivial when these panoramas take about 2-4 GB. It is reasonable to cut them into smaller panoramas. Smaller panoramas could be as small as this one or as large as this one. One of the issue is clouds as can be seen here. In our case, timing because photos shots was about 23 seconds with a 4 GB SD card. In our second flight, we looked for a 80 second increments with an 8 GB SD card. The second time increment was designed to take advantage of the 20 hours of flight. One of the interesting element, if the flight is to be short, would be to reduce the time increment in order to allow for the camera to swing and take photos sideways. This also requires another RC-motor and a mechanism to allow for the swinging mechanism. When the balloon lands, it is a matter of putting the card into a computer with Autopano which automatically puts these images together into panoramas. Using a software like Zoomify to put these panoramas on the web is essential to reduce the bandwidth between the server and people helping the search. On a side note, both Zoomify and Autopano were supported by very cool team of people.
We eventually did an an assessment of the resolution of the results and it turns out that we have about a 1 meter resolution. Please note that the panoramas such as this one used images with 50 percent lower resolution (that was due to an earlier version of autopano that has since been fixed). Also, in order have an idea of the size of an airplane, we picked two jets during the GeoCam flight. While the low resolution image on this entry is small, the larger image, makes it a non trivial image. The human eye is clearly able to make up this is a plane. This jet is also most probably larger than a Cessna. Some assembly pictures of GeoCam can be found here.
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