IARU Amateur Satellite Frequency Coordination
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IARU Amateur Satellite Frequency Coordination |
| UND Roads 1 & 2 | Updated: 15 Jun 2024 | Responsible Operator | Ronald Fevig K0UND | |
| Supporting Organisation | University of North Dakota | |||
| Contact Person | ronald.fevig@und.edu.nospam | |||
| Headline Details: Our mission aims to establish a satellite operations training facility at the University of North Dakota, for educational purposes. This project will showcase the capabilities of our ground station to determine the orbits of satellites in Low Earth Orbit (LEO). We will achieve this through Doppler and ranging measurements across UHF, VHF, and S-band frequencies. Additionally, the mission includes a demonstration of autonomous navigation and docking techniques using two 3U CubeSats. This aspect of the mission will provide valuable insights and hands-on experience in satellite maneuvering planning and proximity operations. Please reference the included block diagram which shows the communication scheme for each of the satellite links. The CubeSats will provide UHF and VHF digipeater capabilities to the amateur radio community during specific mission phases, ensuring that the power usage does not compromise the primary mission's integrity. The power availability is contingent on the Local Time of the Ascending Node (LTAN) of their sun-synchronous orbits, which, as of now, remains undetermined. This factor is crucial since eclipse durations can range from 0% (around 6:00 AM) to 37% (Noon) of the orbit period, significantly influencing power margins. Equipped with transceivers identical to those in the popular IO-117 (GreenCube) and 1KUNS satellites, the CubeSats support the same GMSK modulation (e.g., 4k8 baud), along with an identical data link layer (ASM + Golay + G2RUH scrambler) and network layer (CubeSat Space Protocol). While AX.25 framing is available, it is not the preferred protocol according to Gomspace guidelines. When operating the digipeater for amateur radio purposes, we will accommodate 1200 baud digital packets. This will allow for maximum availability and compatibility within the amateur radio community. Currently the very popular GreenCube is operating in this digital mode. We aim to initiate the digipeater functionality after the satellite commissioning phase, ~1 month after deployment. This timeline allows us to evaluate operational effectiveness and gauge power consumption in this mode. However, digipeater operations will be suspended to accommodate phasing and homing maneuvers. These maneuvers are essential for aligning the two CubeSats within the same orbital plane and altitude, ensuring they maintain a relative velocity and a distance under 30km. Achieving this configuration not only enables the resumption of digipeater functionality but also allows the CubeSats to function as a space-based UHF/VHF radio gateway, leveraging inter-satellite links, during the far field rendezvous phase and as part of the secondary mission activities. Such operations could support rare grid activations and DXpeditions to remote locations, offering significant value to the broader AMSAT community. This engagement supports pursuits for accolades such as WAZ, WAS, or DXCC awards, enriching the amateur radio experience. Furthermore, and since we are an educational institution focused on space operations, we will strongly encourage students here and elsewhere to receive their amateur licenses and utilize this digipeater heavily. Proposing UHF and (secondary) VHF downlinks using 19k2 GFSK with intersatellite links also using VHF. Planning a SpaceX Transporter 13 launch from Florida in Q1 2025. **Downlinks and inter-satellite links have been coordinated on 145.900 MHz together with downlinks on 435.400 MHz and 2401.875 MHz** | ||||
| Application Date: | 26 Apr 2024 | Freq coordination completed on | 15 Jun 2024 | |
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