There is an effort to map Earth's gravity, GRACE, which has been ongoing since 2002. It's produced this:
Several GRAIL-like missions are planned / in progress / completed.
LISA, a probe designed to measure gravitational fields in space, with hopes of finding black holes.
Magellan mapped Venus' gravitational anomalies.
There is a version of your image with captions
Which tells us that all of these are radio signals, on various frequencies.
The main measurement conducted is continuous, very accurate measurement of the distance between the two spacecraft. This is based on the travel time, and probably the phase of the radio signals between them, compared to the very ...
According to "Operating the Dual-Orbiter GRAIL Mission to Measure the Moon's Gravity" (available at http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.661.47&rep=rep1&type=pdf) the primary science data collected by GRAIL, which is the very accurate measurements of the distance between the two spacecraft made at a very high sampling rate, was ...