When I studied geology we did a gravity survey along a road. The gravimeter was a big metal can; inside there was a weighted arm suspended by a spring. Measuring the differences in the static deflection of the arm gave us a reading of local gravity at each point along the survey.
The can had to be placed perfectly level, and sit for a couple minutes (to allow any vibration in the sensor suspension to dissipate) before taking the reading. We also couldn't take any readings when a vehicle was going past. Luckily this was along a fire road in the mountains, so there was very little traffic.
I've heard of both aerial and underwater (submarine or towed sensor) gravity surveys, and it's so impressive that they get usable data from a moving platform. I think one trick is to do multiple passes so that chaotic sources of error (like turbulence) average out at any given point--while real differences in gravitation would persist.
Edit to add: Going back to my comment above, I can't imagine how a truly portable (like, arbitrarily hand-held) gravity sensor could be developed, the way we have portable sensors for light, radio, sound, ambient pressure, magnetic field, etc.
Most of the moving measurements aren't gravimeters. They're gradiometers.
You don't actually get the same data out, and you can't use it in the same way.
The key part isn't just the acceleration due to motion. It's that you have to know your absolute elevation very precisely if you're using a gravimeter. Otherwise, the data you get can't be corrected relative to your other measurements and is more or less useless. (The method mentioned in the article actually measures the geoid directly by measuring the sea surface, which is an equi-potential surface.)
However, if we don't worry about the absolute acceleration due to gravity, and instead measure the local rate of change in gravity, we don't need to know elevation precisely.
That's referred to as gradiometry. You can't use the data in the same way, but it's still very useful.
In a nutshell, most of the movable gradiometry sensors work by using multiple accelerometers. Acceleration due to motion affects both equally (with some caveats when rotation comes into play). The differences in acceleration between the two accelerometers is therefore purely a result of the "tilt" of the geoid locally.
It's difficult to integrate this back into an accurate picture of what the free air or Bouger anomaly would look like, but it's still useful information. We can't necessarily calculate the same things from it, but it's a great edge detector.
The can had to be placed perfectly level, and sit for a couple minutes (to allow any vibration in the sensor suspension to dissipate) before taking the reading. We also couldn't take any readings when a vehicle was going past. Luckily this was along a fire road in the mountains, so there was very little traffic.
I've heard of both aerial and underwater (submarine or towed sensor) gravity surveys, and it's so impressive that they get usable data from a moving platform. I think one trick is to do multiple passes so that chaotic sources of error (like turbulence) average out at any given point--while real differences in gravitation would persist.
Edit to add: Going back to my comment above, I can't imagine how a truly portable (like, arbitrarily hand-held) gravity sensor could be developed, the way we have portable sensors for light, radio, sound, ambient pressure, magnetic field, etc.