Radio Emission of Air Showers with Energy E$_0$ $\geq$ 10$^{19}$ eV by   Yakutsk Array Data
  In this paper, we present results obtained from the measurements of radio emission at frequency of 32 MHz with energy more than 10$^{19}$ eV. Generalized formula that describe lateral distribution and depends on main characteristic of the air showers: energy E$_0$ and depth of maximum X$_{max}$ was derived. The formula has a good agreement with data at average and large distances from shower axis. Employing the ratio of radio emission amplitude at distances 175 m and 725 m we determined the depth of maximum X$_{max}$ for air shower with energy 3.7$\cdot$10$^{19}$ eV, which in our case is equal to X$_{max}$ = 769$\pm$34g$\cdot$cm$^{-2}$. 
S. Knurenko, I. Petrov, Z. Petrov
astro-ph.HE