New ask Hacker News story: Ask HN: Help on SAR/deconvolution for an ultrasonic phased array radar
Ask HN: Help on SAR/deconvolution for an ultrasonic phased array radar
3 by belzebalex | 1 comments on Hacker News.
This is as much a Ask HN as a Show HN of my first results: For the past three years, I've been on-and-off building an ultrasonic 3D scanner using an active phased array emitter. Just had the first successful results. It images its surroundings by sending an ultrasonic wave train in a specific direction and listening for the echos. Linked to some photos in a first comment. Currently, I'm just plotting in 3D all the points for which the intensity of the received signal is above a threshold. The problem with that is that my beam is large (a dozen centimeters at two meters, see my comment below) so one small detail of the scene gets a larger 3d representation because the beam is large. The scan looks like a blurred image. I know this problem has already been solved. If I understand correctly, SAR radars create very long and blurry images of the ground from a satellite and then use an algorithm to "unblur" them. I guess that the blurred image my sonar generates is a sort of convolution of the scene that could be represented by a matrix, and that I just have to find the right inverse matrix, convolve it on my results to get a good image back. I can't find any good and intuitive explanations on devoncolutions/sar algorithms. The only ressources I found are research papers of which I have trouble reading the maths and fail to apply to my own use case (I'm a 19yo in a French preparatory school, so I've only been doing real maths for 2 years). How could I solve that problem? Am I completely misled to think that it's possible? (maybe the "blurring" transformation is irreversiblei.e. losing too much information)
3 by belzebalex | 1 comments on Hacker News.
This is as much a Ask HN as a Show HN of my first results: For the past three years, I've been on-and-off building an ultrasonic 3D scanner using an active phased array emitter. Just had the first successful results. It images its surroundings by sending an ultrasonic wave train in a specific direction and listening for the echos. Linked to some photos in a first comment. Currently, I'm just plotting in 3D all the points for which the intensity of the received signal is above a threshold. The problem with that is that my beam is large (a dozen centimeters at two meters, see my comment below) so one small detail of the scene gets a larger 3d representation because the beam is large. The scan looks like a blurred image. I know this problem has already been solved. If I understand correctly, SAR radars create very long and blurry images of the ground from a satellite and then use an algorithm to "unblur" them. I guess that the blurred image my sonar generates is a sort of convolution of the scene that could be represented by a matrix, and that I just have to find the right inverse matrix, convolve it on my results to get a good image back. I can't find any good and intuitive explanations on devoncolutions/sar algorithms. The only ressources I found are research papers of which I have trouble reading the maths and fail to apply to my own use case (I'm a 19yo in a French preparatory school, so I've only been doing real maths for 2 years). How could I solve that problem? Am I completely misled to think that it's possible? (maybe the "blurring" transformation is irreversiblei.e. losing too much information)
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