Narrow band radio emissions are observed with the radio astronomy experiment on ISEE 3 from a position 0.01 AU upstream of the earth. These are interpreted as radio line emission generated at twice the local plasma frequency in the vicinity of the earth's bow shock by energetic particles. The frequency of the 2fp radio emission is well correlated to large scale density changes observed by both the LASL plasma experiment and the radio experiment at ISEE 3, about one hour earlier in accordance with the transit time of the solar wind to the bow shock region. The bandwidth of the 2fp emission varies from less than 3 kHz to more than 20 kHz and is likely broadened by solar wind density variations across the source region. The 2fp source is visible about 50% of the time and the position of its centroid is usually located within 30 RE of the subsolar point, but at times is observed at a distance of up to 60 RE. However, these positions may have systematic errors if significant linear polarization is present in the observed radiation or if refraction takes place along the ray path. Intensity variations of 20 db and apparent motions of 40 RE can occur with time scales of minutes.