Delay-based fill level measurement device, comprising: a transmission unit (501, 502) for emitting a transmission signal, which is reflected on a filling material surface of a filling medium and at least on a second reflector (506, 512); a reception unit (501, 513) for receiving the reflected transmission signal (509, 510), which is an echo curve comprising a plurality of echoes (704, 701, 703); an evaluation unit for carrying out a tracking method for grouping echoes, which originate from identical reflectors in echo curves received at different times, the evaluation unit being configured to carry out the following steps: (a) determining a first track of a first group of echoes which originate from a first reflector and a second track of a second group of echoes which originate from a second reflector, each track describing the time delay of the corresponding transmission signal from the transmission unit to the reflector assigned to the track and back to the reception unit at the various times (t 1, t 2, t 3, t 4) characterized in that: (b) determining a linear relationship between the first track and the second track, which can be described mathematically as: D T 2, k = a 1 ⋅ D T 1, k + a 0 + e k wherein D T 2, k is the position of the track T 2 of the measurement at time k, wherein D T 1, k is the position of the track T 1 of the measurement at time k, (c) determining one or more variables from the linear relationship between the first track and the second track. a transmission unit (501, 502) for emitting a transmission signal, which is reflected on a filling material surface of a filling medium and at least on a second reflector (506, 512); a reception unit (501, 513) for receiving the reflected transmission signal (509, 510), which is an echo curve comprising a plurality of echoes (704, 701, 703); an evaluation unit for carrying out a tracking method for grouping echoes, which originate from identical reflectors in echo curves received at different times, the evaluation unit being configured to carry out the following steps: (a) determining a first track of a first group of echoes which originate from a first reflector and a second track of a second group of echoes which originate from a second reflector, each track describing the time delay of the corresponding transmission signal from the transmission unit to the reflector assigned to the track and back to the reception unit at the various times (t 1, t 2, t 3, t 4) characterized in that: (b) determining a linear relationship between the first track and the second track, which can be described mathematically as: D T 2, k = a 1 ⋅ D T 1, k + a 0 + e k wherein D T 2, k is the position of the track T 2 of the measurement at time k, wherein D T 1, k is the position of the track T 1 of the measurement at time k, (c) determining one or more variables from the linear relationship between the first track and the second track. (a) determining a first track of a first group of echoes which originate from a first reflector and a second track of a second group of echoes which originate from a second reflector, each track describing the time delay of the corresponding transmission signal from the transmission unit to the reflector assigned to the track and back to the reception unit at the various times (t 1, t 2, t 3, t 4) (b) determining a linear relationship between the first track and the second track, which can be described mathematically as: D T 2, k = a 1 ⋅ D T 1, k + a 0 + e k wherein D T 2, k is the position of the track T 2 of the measurement at time k, wherein D T 1, k is the position of the track T 1 of the measurement at time k, (c) determining one or more variables from the linear relationship between the first track and the second track. wherein D T 2, k is the position of the track T 2 of the measurement at time k, wherein D T 1, k is the position of the track T 1 of the measurement at time k, (c) determining one or more variables from the linear relationship between the first track and the second track.