|OPERATIONS of PSAT-2 IN THE AMATEUR SATELLITE SERVICE 18 Nov 2016 |----------------------------------------------------------------------- | WB4APR | |This paper addresses the licensing of PSAT-2 in the Amateur Satellite |Service. It extracts the pertinent sections of the IARU (International |Amateur Radio Union) guildelines for INFORMATION FOR PROSPECTIVE OWNERS |AND OPERATORS OF SATELLITES UTILIZING FREQUENCIES ALLOCATED TO THE |AMATEUR-SATELLITE SERVICE which helps assure compliance with the ITU |rules. This document may be viewed in its entirety at: |http://www.iaru.org/uploads/1/3/0/7/13073366/iarusatspec_rev15.7.pdf | |RULES: | "Amateur-Satellite Service: A radiocommunication service using space | stations on earth satellites for the same purposes as those of the | amateur service." [RR S1.57] | | "Amateur Service: A radiocommunication service for the purpose of | self-training, intercommunication and technical investigations | carried out by amateurs, that is, by duly authorised persons | interested in radio technique solely with a personal aim and without | pecuniary interest." [RR S1.56] | |PSAT-2 COMMENT: | |Sponsoring Organization: US Naval Academy |Operating Organization: US Naval Academy Amateur Radio Club W3ADO |Station Trustee: Bob Bruninga, WB4APR |Satellite Station Licensee: Todd Bruner, WA1HAI | |Bob Bruninga is the senior research engineer in the Naval Academy |Student project lab who gives engineering guidance to student |satellite projects. | |Todd Bruner is an active friend of the Academy, a past faculty at |USNA and now retired Naval Officer who lives only blocks from the |Academy. He has NO PECUNIARY association with the US Naval Academy, |NRL, NASA nor any other Organization involved in this project. | |RULES: | | "VI. OPERATIONAL GUIDELINES. The following operational guidelines, | based on interpretations by IARU of the Radio Regulations and good | amateur practice, are intended to help in planning the missions, | management, and control of satellites planned to operate in the | amateur-satellite service. | | Organisations building satellites should compare their mission | plans to the requirements of the amateur-satellite service. Then, | they should determine if it is possible to comply with the | requirements of the amateur-satellite service or if licensing and | operation should be in some other radio service which is more | consistent with the nature and requirements of the mission. | |RULE: A. Positive Transmitter Control. | | You must be able to turn off the space station transmitter | immediately in case of interference. [RR25.11 & RR 22.1] | | In practice the meaning of "immediate" probably varies a little, | depending on the situation. If interference is caused to a SAFETY | SERVICE, immediately means NOW: no more than minutes or a few | tens of minutes. Interference to other services should terminate | in no more than a few hours. | | Positive transmitter turn-off signals shouild use an independent | telecommand receiver on the space station. Telecommand on a user | input frequency means that another transmitter can interfere easily | with your telecommand signal so so as to obstruct control. | | An adequate network of well placed earth statinos capable of | sending control signals to the satellite reduces the time required | to issue the turn off command. Other mechanisms might be (1) a | transmitter time-out timer independent of the houskeeping or | control computer; or (2) limiting the space statio's power budget | so that it will run out of energy and sop operating in a reasonably | short time. | |PSAT-2 Comment: PSAT-2's packet transmitter operates in a time-division |multiplex environment where it operates in a low-TX-duty-cycle |mode, designed to share the channel with users, and other satelites |and systems. PSAT-2's transmitter can be shut down within the |requirement of this rule: | |1) PSAT-2 has an independent packet-length watch dog timer that limits |packet length to 1.5 seconds maximum each. | |2) PSAT-2's Comm control system has a watchdog timer on the comm |system that detects loss of control once a minute and re-boots the |comm processor which would also reset any stuck transmitter. | |3) PSAT-2's command and control processor also has a watchdog timer |that reboots the command and control system to defaults if the |process or locks up. | |4) PSAT-2's 4 watt transmitter power (8 watts DC input) exceeds the |spacecraft's power budget by a factor of 5 or more, and will |deplete the system power in under an hour of a stuck transmitter. | |5) PSAT-2 uses FM for the command link, and so even in the presence |of a jamming signal, a command signal only 10 dB stronger than |the jammer is needed to execute the transmitter off command. This |10 dB command ratio is easily assured: | | a) Through the use of multiple ground command stations through | out the world separated in time by 10's of minutes in different | footprints that can avoid any single jammer. | | b) The geometry of any single pass over a command station and | jammer varies by at least 6 to 8 dB simply due to the range | equation, plus 4 to 8 dB due to the variation in antenna | pattern. Combined, these allow a variation between 10 to 32 dB | between the jammer and the command station, giving assurance | that the one-second shut-down command can be received. | |RULE: B. The purposes of an amateur satellite should be to: | | (1) Provide communication resources for the general amateur | radio community and/or | (2) Self training and technical investigations relating to | radio technique. [See RR S1.56 and RR S1.57.] | | "Radio technique," means having a reasonable possibility of | application to radio communication systems. [RR S1.56 and | RR 11.57 and RR 25.2] | | Examples relating to radio technique include but are not limited | to communiction protocols, attitude determination methods, command | and control procedures, receivers, transmitters, and transponders. | Also antennas, sensors to study spacecraft performance, telemetry | protocols, power supplies and controls for use in space. In | addition, spacecraft computers, memory operating systems, programs | and related items; radiation effects on electronic components; | radio wave propogation, meteor trail reflection, and measurements | of orbital environment. | | While many other types of technical investigations are conceivable, | those not having a reasonable possibility of application to radio | communication systems are probably not in accordance with the | treaty requirements. An administration can reject whatever it | decides is inappropriate use of the amateur-satellite service or | questions may be raised by other administrations. | |PSAT-2 COMMENT: PSAT-2 is fully in compliance with the purposes above. | |1) The PSAT-2 communication system primary mission is to be a two-way |transponder in support of amateur radio communications, particularly |remote data relay, text messaging, and situational awareness. | |2) The secondary (PSK31) communications transponder operates as a two- |way PSK-31 transponder in full support of amateur users. | |3) The extremely low-cost design and components on PSAT-2 provide space |heritage for other small amateur satellite builders. | |RULES: C. Station Control. Who may operate a transmitter | | All stations operating in the amateur service and the amateur- | satellite service, including space and Earth stations, must be | controlled by "duly authorised persons," that is, individual | licensed amateur radio operators who must be acting "solely with | a personal aim and without pecuniary interest." [S1.56 & S1.57.] | | Even with these limitations, organizations and amateurs have | common interests and work together for their mutual benefit. | (For this discussion, an organisation can be a university, | research institute, for-profit or not-for-profit corporation, | association, club, or other similar entity.) | | AMSAT-NA, (North America) for example, is an organization which owns | and builds satellites to operate in the amateur-satellite service. | But, because it is an organization and not an individually licensed | radio amateur, it may not control an amateur station. The FCC does | not issue specific amateur radio spacecraft licenses. The AMSAT-NA | spacecraft are simply operated under the individual Licenses of the | individual amateur radio operator who is solely responsible for the | proper operation in accordance with the FCC and ITU/IARU rules. The | license of an amateur radio club (in this case, AMSAT-NA itself) may | also be used where a licensed amateur radio operator is named on the | license as trustee (the person responsible) for the club station. | | In every case, one individual, a licensed amateur radio operator, | who is neither employed nor paid by AMSAT-NA, is legally | responsible for the operation of each amateur station or amateur- | satellite station. | | Commonly, the licensee is an unpaid member of the organization | owning the amateur station equipment or is a volunteer acting | in close association with it. In these cases, the owner's interest | and the licensee's "personal interest" are usually the same. | | Of course, it is theoretically possible (although to the best of | our knowledge, it has never occurred in practice) that the | licensee or trustee of an amateur station or amateur-satellite | station may determine that something he or she has been requested | to do is not in accordance with the rules and regulations of the | licensing administration. If this happens, the licensee would | inform the organization and, if possible, they would work out a | solution that satisfies and protects both. | | Thus, the individual responsibility of each licensed amateur | radio operator, imposed by the Radio Regulations, works as a | legal safety check for the organization and the amateur to protect | both of their interests and those of the amateur satellite service | as well. | |PSAT-2 COMMENT: PSAT-2's organizational structure and operators are |compliant with these rules. The operating organization is the school's |Amateur Radio Club with WB4APR as the licensed trustee of the station |and the licensed control operator for the satellite will be Todd Bruner, |WB1HAI as noted above. The interest of these individuals is in the |operation of the satellite for personal training and intercommunications |with other satellite experimenters in the amateur satellite service and |without pecuniary remuneration for such interest. Bob Bruninga has a 30 |year non-pecuniary history with the Amateur Satellite Service, the author |of dozens of related papers in AMSAT and other Amateur Radio publications, |and the instigator of Packet Radio APRS position reporting via SAREX, MIR, |ARISS, SUNSAT, SAPPHIRE, PCSAT1,2, ANDE, RAFT and PSAT for purely personal |aims of promoting student education and the Amateur Satellite avocation. | | |RULE: E. Permissible communications: | The amateur-satellite service, by its nature, involves stations of | more than one country. Transmissions between amateur stations of | different countries must be limited to communications consistent with | the purpose of the amateur service [RR 1.56] and to remarks of a | personal character [RR25.2]. | | Transmissions between amateur stations on different conutries may not | be obscured. THis means that (1) technical descriptions of all | emissions, codes, and formats must be made publicly and widely | available and that (2) technical descriptions must be sufficient to | enable any technically competent licensed amateur radio operator to | use the system. You may do nothing intended to conceal the meaning | of a tranmission, except in the case of space telecommand | transmissions for critical spaeccraft functions [RR 25.2A] | |PSAT-2 COMMENT: The design, telemetry, data and all aspects of PSAT-2 are |in plain language (AX.25 protocol) and all details are published and |maintained current on the following WEB page: |http://www.aprs.org/psat-2.html | |RULE: F. Open Access. | All telecommunication facilities, except telecommand, operating in | amateur satellite service allocations should be open for use | by amateur radio operators world-wide. All experiments utilizing | frequencies allocated to the amateur-satellite service should be freely | available for use by radio amateurs world-wide and incidentally for | reception by students and educators. | |PSAT-2 COMMENT: All communications modes except telecommand and all |telemetry will be available to all amateur radio operators worldwide in |accordance with the published user operating recommendations. There is |no other usage of these communications transponders, nor circuits beyond |what has been described here for use in the Amateur Satellite Service. |PSAT-2's transponders are available to radio amateurs worldwide who adhere |to the published recommended user station requirements and uplink |parameters. | |Bob Bruninga, WB4APR |Trustee, |US Naval Academy Amateur Radio Club |410-293-6417