  The antenna array LOPES is set up at the location of the KASCADE-Grande
extensive air shower experiment in Karlsruhe, Germany and aims to measure and
investigate radio pulses from Extensive Air Showers. The coincident
measurements allow us to reconstruct the electric field strength at observation
level in dependence of general EAS parameters. In the present work, the lateral
distribution of the radio signal in air showers is studied in detail. It is
found that the lateral distributions of the electric field strengths in
individual EAS can be described by an exponential function. For about 20% of
the events a flattening towards the shower axis is observed, preferentially for
showers with large inclination angle. The estimated scale parameters R0
describing the slope of the lateral profiles range between 100 and 200 m. No
evidence for a direct correlation of R0 with shower parameters like azimuth
angle, geomagnetic angle, or primary energy can be found. This indicates that
the lateral profile is an intrinsic property of the radio emission during the
shower development which makes the radio detection technique suitable for large
scale applications.
