March 1970 | NTIA Technical Memo ERL TM ITS 225
Evaluation of swept frequency (CHIRP) digital signalling for transmitting synoptic data over the HF radio channel
Gene G. Ax
Abstract: Swept frequency (CHIRP) modulation is analyzed as to its suitability for use in the Integrated Global Ocean Station System (IGOSS), a system for the collection of synoptic data from ocean platforms (buoys and/ or ships) using high frequency (HF) radio channels. This 226 modulation technique was found to be undesirable for this application because of its inability to support high aggregate signalling rate s in a 3-kHz HF band with acceptable error rates under the constraints imposed by the requirements of the IGOSS.
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