# The Analysis of Experimental Deployment of IGLUNA 2019 Trans-Ice Longwave System
## 5 Transmission Performance Comparison of Propagation Models  
### Long-Range Receptions  
Every day marked by the functional loop antennas, after applicable transmitter and antenna checks [23], the system went into operation. The basic goal of it was the communication channel through the ice ceiling of the Glacier Paradise, enabling the sending of data/telemetry between the simulated lunar habitat and the surface EVA (extravehicular) team. The emitted signals would be picked up by the receivers mentioned before (with Neywa being the smallest one-most convenient for the EVA activities).  
During the initial runs of the system the quality of the signal in the glacier remained satisfactory and clear; in the later days the LW frequency band has become cluttered with industrial emissions, generated by the PWM controllers as well as the maintenance- and construction equipment, rendering the Klein Matterhorn 270 kHz reception impossible (except for a single'sweet spot' on the surface of the glacier, however impractical for the EVA activities).  
To rectify the problem, the operation of the entire experiment was modified; the 2.4-GHz surface system operated independently from the habitat, and the longwave system tests aimed at long-range reception outside Klein Matterhorn (without any changes to the previously defined transmitters' power). Experimentally, two transmitters were coupled to the same antenna, operating on 270 kHz as the main frequency for A3E-SC telephony (acoustic signal, classical music) and on 266/274 kHz subcarrier with P1A (narrow-bandwidth amplitude-modulated impulses) telemetry--the frequencies were chosen in a way that both emissions reside in the broadcasting bandwidth of 9 kHz, not interfering with adjacent LW broadcasts. To achieve the long-range reception, a wide group of LW listeners was mobilized via social media to monitor the LW bandwidth outside the range of RKS Topolna.  
The signal was successfully received more than once; the farthest and best quality recording came from Finland at the location of KP20 JO [7]. The transmissions were received to the north of Helsinki at 60.6\({}^{\circ}\)N 24.8\({}^{\circ}\)E, making the distance of 2077.06 km from Klein Matterhorn (see Figure 13), with the transmitter located at 3868 m a.s.l. and the receiver at 27 m a.s.l.  
Figure 12: Both IGLUNA 2019 longwave transmitters inside the simulated lunar habitat in the Glacier Paradise, 3868 m a. s. l. The modulation (acoustic) signal is generated directly by a tablet for the ‘glass dome’ transmitter and by an STM32-based microcontroller circuit for the ‘Thermos’ transmitter. The Jowita 2 radio receiver for on-site modulation control can be seen on the left. The pink glow of the stand is created by one of the nearby experiments. The map above the transmitters shows the signal coverage of 225 kHz (Sølec Kujawski) and 270 kHz (Topolna) for comparison. Photograph by the Author.  
With the receiver's noise at 0.010 \(\upmu\)V/m, the A3E-SC signal was recorded at approximately 0.016 \(\upmu\)V/m and the P1A at approximately 50 \(\upmu\)V/m--values making the signal barely detectable for ordinary commercial LW broadcasting receivers (specialized equipment needed), yet still surpassing in this location its stronger but low-land counterpart of RKS Topolha by nearly \(775\times 10^{3}\) times for the E field intensity of the carrier and nearly 500 times for the E field intensity of the sidebands [8].  
Comparing the obtained results (maximum range and frequencies employed) with the formulas given by [PERSON] [24] for the angle of arrival of the radio wave travelling along the surface of the earth for a given range, the approximate angle of arrival reaches \(\sim\)1 degree--which may indicate that the wave propagated directly, without multiple reflections from the ionosphere or ground surfaces.