Delay-based fill level measurement device, comprising: a transmission unit for emitting a transmission signal, which is reflected on a filling material surface of a filling medium and at least on a second reflector; a reception unit for capturing the reflected transmission signal, which is an echo curve comprising a plurality of echoes; an evaluation unit for carrying out a tracking method for grouping echoes originating from identical reflectors from echo curves captured 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 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; characterized by the following steps: (b) determining a linear relationship between the first track and the second track, which can mathematically be described by the following equation: D T 2, k = a 1 ⋅ D T 1, k + a 0 + e k; wherein D T2,k is the position of track T 2 of the measurement at time k; wherein D T1,k is the position of track T 1 of the measurement at time k; (c) assigning a first echo of a further echo curve to the first track, the further echo curve having been received at a later moment than the echo curves in a sequence over time; (d) determining an expected position of a second echo of the further echo curve by calculating the expected position by taking account of the position of the first echo of the first track and the linear relationship; (e) establishing whether the expected position of the second echo corresponds to an actual position of an echo of the further echo curve and, if so, assigning the second echo to the second track. a transmission unit for emitting a transmission signal, which is reflected on a filling material surface of a filling medium and at least on a second reflector; a reception unit for capturing the reflected transmission signal, which is an echo curve comprising a plurality of echoes; an evaluation unit for carrying out a tracking method for grouping echoes originating from identical reflectors from echo curves captured 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 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; (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 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; characterized by the following steps: (b) determining a linear relationship between the first track and the second track, which can mathematically be described by the following equation: D T 2, k = a 1 ⋅ D T 1, k + a 0 + e k; wherein D T2,k is the position of track T 2 of the measurement at time k; wherein D T1,k is the position of track T 1 of the measurement at time k; (c) assigning a first echo of a further echo curve to the first track, the further echo curve having been received at a later moment than the echo curves in a sequence over time; (d) determining an expected position of a second echo of the further echo curve by calculating the expected position by taking account of the position of the first echo of the first track and the linear relationship; (e) establishing whether the expected position of the second echo corresponds to an actual position of an echo of the further echo curve and, if so, assigning the second echo to the second track. (b) determining a linear relationship between the first track and the second track, which can mathematically be described by the following equation: D T 2, k = a 1 ⋅ D T 1, k + a 0 + e k; wherein D T2,k is the position of track T 2 of the measurement at time k; wherein D T1,k is the position of track T 1 of the measurement at time k; wherein D T2,k is the position of track T 2 of the measurement at time k; wherein D T1,k is the position of track T 1 of the measurement at time k; (c) assigning a first echo of a further echo curve to the first track, the further echo curve having been received at a later moment than the echo curves in a sequence over time; (d) determining an expected position of a second echo of the further echo curve by calculating the expected position by taking account of the position of the first echo of the first track and the linear relationship; (e) establishing whether the expected position of the second echo corresponds to an actual position of an echo of the further echo curve and, if so, assigning the second echo to the second track.