New tidal solutions from laser tracking of eight geodetic satellites and from a constellation of radar altimeters are combined to determine the complex Love number \(k_2\) for four lunar tidal constituents in the diurnal and semidiurnal bands. The tidal solutions for each data type must account for inconsistent prior Love numbers; the altimetry community has historically used elastic Love numbers. Use of the complex Love numbers recommended by current international conventions results in a small (order 4%) discrepancy between altimeter and tracking solutions for the degree-2 prograde spherical harmonics; this points to an anelastic Earth model that is too dissipative, with a phase lag slightly too large. Our estimated phase lag for \(k_2\) varies slightly across the tidal bands, from \(0.228^{\circ } \pm 0.024^{\circ }\) for \(\hbox {O}_1\) to a smaller \(0.178^{\circ } \pm 0.020^{\circ }\) for \(\hbox {M}_2\) , with corresponding tidal Q rising from 250 to 320. Results for \(\hbox {N}_2\) and \(\hbox {Q}_1\) are consistent, but with much larger uncertainties. There is some interdependence on the values adopted for other Love and loading numbers, which we account for. A possibly important systematic error arises from seawater density, needed to relate ocean tidal elevations to gravitational Stokes coefficients. A constant mean density of 1035 kg \(\hbox {m}^{-3}\) is used, but allowance for spatial variations in ocean density may be necessary.
