CAP congress, Ottawa, June 13-17, 2016 Monitoring HF transmissions with the e-POP RRI instrument on the CASSIOPE Satellite Donald Danskin Donald.Danskin@Canada.ca Natural Resources Canada H.G. James james@phys.UCalgary.ca CAP congress, Ottawa, June 13-17, 2016

Introduction NRCan operates a HF transmitter in Ottawa for monitoring the ionospheric propagation at the high latitudes. The transmissions alternate between CW or Barker coded Binary Phase Shift Keying (BPSK) that introduces 180 phase shift at known intervals. The transmissions can be received either on the ground or at satellites with HF receivers such as RRI on CASSIOPE. Inverted V antenna with optimal signal at low elevation angles (omnidirectional). RRI has crossed dipoles oriented toward Tx

Examples of HF transmission of BPSK B2000  0.5 msec I/Q receiver

Animation courtesy of A. Howarth, U of Calgary

Spectral plot of 4 minute pass Tx operational mode 0.9 s tone 1.1 s off 7.0 s BPSK 1.0 s off Repeat every 10 s Start of BPSK and tone GPS timed Stop Tx Start Tx Frequency

Gillies, R. G. , G. C. Hussey, G. J. Sofko, and H. G Gillies, R. G., G. C. Hussey, G. J. Sofko, and H. G. James (2012), Modeling measurements of ionospheric density structures using the polarization of high-frequency waves detected by the Radio Receiver Instrument on the enhanced Polar Outflow Probe, J. Geophys. Res., 117, A04316, doi:10.1029/2011JA017457. James, H. G., R. G. Gillies, G. C. Hussey, and P. Prikryl (2006), HF fades caused by multiple wave fronts detected by a dipole antenna in the ionosphere, Radio Sci., 41, RS4018, doi:10.1029/2005RS003385.

Frequency shift ? Doppler shift + Difference in LO’s

BPSK pulse used to estimate propagation time Prime axis Orthogonal axis

Apparent propagation delay

Ionosonde data

Amplitude Fading

Gillies, R. G. , G. C. Hussey, H. G. James, G. J. Sofko, and D Gillies, R. G., G. C. Hussey, H. G. James, G. J. Sofko, and D. André (2007), Modelling and observation of transionospheric propagation results from ISIS II in preparation for ePOP, Ann. Geophys., 25, 87–97.

Conclusion Reception of transmissions of both tone and BPSK show the expected Doppler shift due to motion of the satellite and can used to characterize the difference in local oscillator frequencies The lack of signal detected by RRI at low latitudes indicates that rays are bent back to Earth by the ionosphere Excess time delay indicates that longer ray paths are taken due to ionospheric refraction. Sporadic E events cause a significant delay Faraday rotation is observed with signal strength alternating between the orthogonal antenna Fading rates are consistent with modelled theory up to ~3 Hz.