A method of determining a filling level (L) of a product in a tank using a radar level gauge system , the method comprising: determining a measure indicative of a presently available power for operation of the radar level gauge system ; determining , based on the measure indicative of the presently available power for operation of the radar level gauge system, a maximum number (N) of measurement operations to be performed for determination of the filling level, such that the maximum number becomes relatively small when the measure indicates that the presently available power is relatively low, and the maximum number becomes relatively large when the measure indicates that the presently available power is relatively high; performing a set of measurement operations including a number of measurement operations that is less than or equal to the maximum number (N) of measurement operations, each measurement operation including: generating and transmitting an electromagnetic transmit signal (S T,n ); propagating the transmit signal (S T,n ) towards a surface of the product in the tank ; receiving an electromagnetic reflection signal (S R,n ) resulting from reflection of the transmit signal (S T,n ) at the surface of the product; and forming a measurement signal (S IF,n ) indicative of a timing relation between the transmit signal (S T,n ) and the reflection signal (S R,n ); and determining the filling level (L) based on a set of measurement signals including the measurement signal (S IF,n ) formed in each measurement operation in the set of measurement operations. determining a measure indicative of a presently available power for operation of the radar level gauge system ; determining , based on the measure indicative of the presently available power for operation of the radar level gauge system, a maximum number (N) of measurement operations to be performed for determination of the filling level, such that the maximum number becomes relatively small when the measure indicates that the presently available power is relatively low, and the maximum number becomes relatively large when the measure indicates that the presently available power is relatively high; performing a set of measurement operations including a number of measurement operations that is less than or equal to the maximum number (N) of measurement operations, each measurement operation including: generating and transmitting an electromagnetic transmit signal (S T,n ); propagating the transmit signal (S T,n ) towards a surface of the product in the tank ; receiving an electromagnetic reflection signal (S R,n ) resulting from reflection of the transmit signal (S T,n ) at the surface of the product; and forming a measurement signal (S IF,n ) indicative of a timing relation between the transmit signal (S T,n ) and the reflection signal (S R,n ); and generating and transmitting an electromagnetic transmit signal (S T,n ); propagating the transmit signal (S T,n ) towards a surface of the product in the tank ; receiving an electromagnetic reflection signal (S R,n ) resulting from reflection of the transmit signal (S T,n ) at the surface of the product; and forming a measurement signal (S IF,n ) indicative of a timing relation between the transmit signal (S T,n ) and the reflection signal (S R,n ); and determining the filling level (L) based on a set of measurement signals including the measurement signal (S IF,n ) formed in each measurement operation in the set of measurement operations. <EOS>