Hi.
A little backstory first. Feel free to skip this paragraph and go straight to the project idea. I play a lot of frisbee golf and on some courses there are these ponds which if your disc lands in it you have essentially lost it. It is a muddy pond with some semi thick plants growing from the bottom and very muddy bottom. Today I went there with to try to fetch some discs out from there and went all the way in but was not able to see anything do to the vegetation and the mud that blocks the vision even more. I found a few disc just by accident by stepping on them and then kicking them upwards. So that is what inspired me to try to find some solution using electronics.
So the idea I had was to put an ultrasonic sensor on a remote controlled toy boat and scan the water to create some kinda map of the pond. The idea is that the discs would create some anomaly from the rest of the area. The problems I see are that ultrasonic sensors are not really meant to be used through water since they are high frequency. The vegetation would probably be detected by the sensor so the data in the best case would just represent the highest points of the vegetation.
My question is if this is at all feasible?
Any other ideas are very much welcome since a lot of discs get eaten by these ponds and it is very annoying.
simmisj:
Any other ideas are very much welcome since a lot of discs get eaten by these ponds and it is very annoying.
It's not electronic but, is there any way you could glue a disc of closed-cell foam to the underside? This might be enough to make the Frisbee float so, no searching involved.
I wonder would the Frisbee still fly if you were to attach a piece of very thin steel to it - perhaps a strip inside the rim. Then you may be able to recover it with a strong magnet.
Finding things in muddy water is not easy. My bicycle was pulled off the roof of a canal boat by a low tree. I was going very slowly so It seemed like I could pinpoint the position where the bicycle fell in the canal. It took me about 20 minutes to find it with my boat hook
I beleve what you are looking for is a true sonar, possibly a sidescan sonar
then software to take the scans and mesh them to extrapolate any inconsistances on the floor of the pond
and then probably also a ground penetrating sonar that will differentiate between hard objects and the silt.
or, from soft objects and the silt.
when you look at stealth in the early days, a flat sheet of steel was undetectable if it were on an angle
but a round object, like the aerodynamic shape of an airplane, would have multiple sponts that reflected the radar back to the receiver. Radar became so sensitve that the periscope of a submarine was detetable.
so in your lake, you might be able to detect something the size of a quarter, with the right gear. (not saying it exists)
something round would be easier because it would always have one surface that reflected back.
the Frisbee may not be dense enough as compared to the background. something much harder might be easier to detect.
however, i am not confident that ground penetrating radar can detect a rock under ground, it seems to me that they can detect tunnels or open caverns, but not objects in the soil.
then to detect things under the bottom layer of the bed of a lake, from a distance through the water.....
I would offer that a few hours with google would yield be wise in order to find any sensors that might work.
wvmarle:
Not the submarine itself, as radar won't work under water. It's using high frequency radio waves after all...
Yes. The periscope is the bit that sticks out of the water. Radar woks in air.
By the end of WWII radar was sufficently sensitive enough to detect something that small from some distance.
