Detecting the Moon!

A project log for A new high accuracy tilt sensor

This project aims to build a tilt sensor that is cheap, very accurate and has a wide measuring range (up to 360 degrees).

Aron MolnarAron Molnar 10/09/2016 at 01:361 Comment

If the sensor is truly can reach that high resolution and sensitivity, it's theoretically capable of detecting the gravitational effect of the Moon.

To test the theorem I made a Linear FCDT especially for this experiment. This sensor should have a big L/R ratio (L: length of one coil, R: radius of the cell) (whys explained in this log:, and extremely symmetrically winded secondary coils. I made a sensor that has an L/R ratio of 20 or so: it's 196 mm long, the cell's inner diameter is 6 mm, has 5 layers of 0.25 mm coil wire in each coil, and looks something like this:To get reliable data from the sensor, we have to take it to a very massive and vibration-free place and make measurements with it for at least 3 days in a row. We found the proper place at the University of Pannonia on top of a high-tech CNC machine. To make it convenient, I made a little program in LabVIEW that sends the measured data to my email address at every 12th hour for 3 days (the program's VI can be found in 'Files' section).

The measurement was started on 7th of Oct at 11:47 a.m. (GMT+2:00) and we're planning to continue it for 1,5 week.

We got some anomalies in the data, but there is one encouraging fact: we detected a little sine wave signal that got a periode of 24 hours.

This means that we almost detected the gravitational effect of our Moon!


John Leeman wrote 11/04/2016 at 14:19 point

Hello! Great project. If you'd like, I have a gravitational tide model ( that I would be happy to run for the 3 day time span you collected your data and provide for comparison to see if it lines up or if thermal/other effects creeped into the data. Gravitational tide is tricky since it has the same period as a bunch of other signals. It'll take all of 5 minutes to setup the model, I just need the lat, lon, elevation, and date range. Cheers and congrats again on a great project!

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