This paper presents observations of field-aligned electron flux bursts from the auroral sounding rocket flight, Alaska 2000, launched February 25, 2000 from Poker Flat, Alaska. In one particular energetic electron burst, the field-aligned electron flux is observed to be modulated at 22--30 Hz at energies up to 30 keV. By assuming that the observed energy dispersion in the bursts is caused by time-of-flight effects, we obtain characteristic source altitudes of 87 dispersive electron bursts, and find that the average characteristic source altitude of the bursts is 4015 ¿ 684 km in the first inverted-V and 5411 ¿ 972 km in the second inverted-V. This result implies that the electron-wave or other interaction depends more strongly on which arc it occurs in, rather than another factor such as energy of the electrons, since dispersive bursts at a wide range of energies and durations were used to arrive at the result.