The small-scale irregularities of equatorial spread-F (ESF) are highly aligned with the geomagnetic field. Aspect angles (rms deviations from perfect alignment) have been found to be routinely less than .01 degree . Measuring angles this small requires the use of radar interferometry because the angles being measured are much smaller than the beamwidth of any incoherent scatter radar. The technique used to measure the aspect angles along with data collected in March, 2009 at the Jicamarca Radio Observatory are presented.