Source: ftp://ftp.amsat.org/amsat/articles/g3ruh/INDEX Last update: 2006 Feb 25 [Sat] 1042 utc by JRM NOTE: All of the G3RUH articles have been converted to HTML format, and are indexed at: http://www.amsat.org/amsat/articles/g3ruh/g3ruh.html The following, however, is not totally obsolete. ______________________________________________________________________________ G3RUH Article Archive - INDEX by James Miller G3RUH Contains: (1) Welcome (2) Articles - Numeric Index (3) Articles - Abstracts (4) AO-13 Telemetry (5) Public Notice (1) Welcome ======= Welcome to the ascii version of this INDEX of my articles, as maintained on the ftp://ftp.amsat.org archive. This INDEX file contains an abstract for each article. Articles are assigned a filename like a123.zip When you have decided what you want to read, perform a normal ftp command: get a123.zip and the file is transferred to your Internet host. Remember to use "binary" mode for the transfer. If you're using a Web browser clicking on the "ftp://" reference will do this automatically. To explode the zip file you need an unzipper such as WINZIP, PKUNZIP etc for the IBM-PC and compatibles, or similar software for the Apple, Acorn and other platforms. Each .zip archive contains the following: ABSTRACT.TXT Abstract and any background notes ARTICLE.TXT The article plaintext ASCII file plus optionally: FIG01.GIF Diagram(s) - a few .JPGs too. FIG02.GIF etc CAPTIONS.TXT OTHER.TXT Any augmenting material, perhaps amsat-bb postings Text lines are generally 76 characters long, terminated with CR+LF ( #0D #0A ) and are confined to the characters #20 - #7E, I hope! GIF files are type GIF87a. There is only one image per GIF file. These formats have been chosen to cover the widest variety of computers, and to ensure that all elements of an article are bound together. (2) Numeric Index ============= FileName kB Uploaded Orig Title --------------------------------------------------------------------------- a100.zip 5 95 Jun 19 85 Dec 30.6 Days hath September a101.zip 5 94 Nov 11 86 Apr 10 Ways To Ensure Failure on Oscar 10 a102.zip 2 94 Nov 11 86 Apr Phase 5 Satellites a103.zip 25 94 Nov 17 94 Jul Icom's IC 820H, A Satellite User's Perspective a104.zip 56 94 Nov 14 89 Jun Planning AO-13 Mode Schedules a105.zip 25 95 Jun 25 90 Feb Shannon, Coding and the Radio Amateur a106.zip 3 94 Nov 18 91 Feb 1991, 1992, 1993 ...and all that a107.zip 51 94 Nov 17 94 Aug Down Memory Lane? a108.zip 160 95 Dec 19 91 Apr The Shape of Bits to Come a109.zip 197 95 Apr 19 88 Oct 9600 Baud Packet Radio Modem Design a110.zip 15 94 Dec 04 94 Apr The Earth Moved a111.zip 56 95 Dec 07 90 Oct PLAN-13 Satellite Position Calc. Program a112.zip 56 94 Dec 04 84 Dec Sun's Up! (Parts 1 - 3) a113.zip 213 94 Dec 04 85 Aug Sensorship - A Question of Attitudes 1 & 2 a114.zip 109 96 May 16 94 Oct The Re-Entry of Oscar-13 a115.zip 34 95 Jan 15 92 Oct Mode-S - Tomorrow's Downlink a116.zip 86 95 Aug 31 93 Apr A 60cm S-Band Dish Antenna a117.zip 180 95 Jan 15 93 Jun A 16 Turn S-Band Helix a118.zip 207 95 Aug 05 93 Oct Managing Oscar-13 a119.zip 162 95 Sep 02 94 Dec An S-Band Beacon [from SSB Electronic] a120.zip 64 95 Feb 09 93 Feb Measure AO-13 Squint Directly! a121.zip 56 99 Feb 03 96 Jun From Hardware to Vapourware; AO-13 Plans a122.zip 68 99 Jan 31 97 Feb Oscar-13's Life and Death a123.zip 80 99 Jan 31 97 Oct Phase III Ranging System a124.zip 265 99 Feb 05 98 Jul The Experimental IHU-2 Aboard P3D Subsequent articles in HTML versions only. See: http://www.amsat.org/amsat/articles/g3ruh/g3ruh.html =========================================================================== (3) Abstracts ========= ---------------------------------------------------------------------------- 30.6 Days hath September Oscar News (UK) 1985 Dec, No.56 p.6-9 A discussion of date algorithms for computer programs, with examples. Also: Amsat-DL Journal Jg.14 Nr.4, 1987 Jul/Aug It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a100.zip ---------------------------------------------------------------------------- 10 Ways To Ensure Failure on Oscar-10 Oscar News (UK) 1986 Apr, No.58 p.26-28 Shows in ironic style how every decibel gained counts, and every decibel squandered is a step into the noise. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a101.zip ---------------------------------------------------------------------------- Phase 5 Satellites Oscar News (UK) 1986 Apr, No.58 p.29 An original proposal for transponder spectral equalisation using digital electronics (DSP) as a means of solving the "alligator" problem. I hoped it might fly on Phase IV, and hoped the same for P3D.. ;-( It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a102.zip ---------------------------------------------------------------------------- Icom's IC-820H, A Satellite User's Perspective Oscar News (UK) 1994 Aug No. 108 p3-7 Review of a satellite "9600 baud data ready" radio - that isn't. Also: Satellite Operator No. 46, July 1994. p1,6-9 It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a103.zip ---------------------------------------------------------------------------- Planning AO-13 Mode Schedules Oscar News (UK) 1989 Jun, No. 77 p.16-17 Explains in detail the constraints that lead to the schedules. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a104.zip ---------------------------------------------------------------------------- Shannon, Coding and the Radio Amateur Oscar News (UK) 1990 Feb No.81 p.11-15 The addition of redundant bits to a data byte achieves an increase data transmission reliability. You send more bits than you started with (and use more bandwidth) so for a fixed transmitter power the intrinsic bit error rate worsens. However the associated error correction schemes more than make up for this apparent penalty. When space communication costs are reckoned in millions of $$$ per db, schemes that provide more bytes for your buck are of the greatest importance. Their use in amateur radio is close. This article is a brief introduction to coding. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a105.zip --------------------------------------------------------------------------- 1991, 1992, 1993 ...and all that Oscar News (UK) 1991 Feb No. 87 p 16-17 19xx January is that time of year for the annual pleas by users of ancient software that they've run out of "siderial whatsits". Gives the table until 2000, and shows you how to calculate it. (It's sidereal, by the way). It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a106.zip --------------------------------------------------------------------------- Down Memory Lane? Oscar News (UK) 1994 Aug No. 108 p16-19 Discussion of Oscar-13's memory EDAC system, and huge rise in memory error rate that occured on 1994 May 13. Startling conclusion. Also: Amsat-VK Newsletter No. 112, 1994 Aug Also: The Amsat Journal (USA) Vol 17 No. 5, Sep/Oct 1994. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a107.zip --------------------------------------------------------------------------- The Shape of Bits To Come Oscar News (UK) 1991 Apr No. 88 p 29-37 This article is about bits, about bandwidth and about control of both. What is the "raised cosine modulation" used on microsats AO-16/18/19? And what is the RSM-8 on Rudak/AO-21? What PSK modulation does Fuji-20 use? Come to that, what is BPSK, and similar abbreviations? Substantial tutorial article, copiously illustrated. Also: Amsat Journal (US) July 1991. Also: ARRL 10th Computer Networking Conference (US), Oct 1991 pps 112-120. Also: Amsat-DL Journal Jg.18 Nr.4, December 1991, Also: Radioaficionados (Spain) Enero 1992. Also: Amsat-OZ (Denmark) 1992 October, No. 8 Also: Radio Communication (RSGB) 1993 September & October. Also: SM-Info (Sweden) 1994 Jan - 1995 Dec Also: "Packet: Speed, More Speed and Applications", ARRL 1995. ISBN 0-87259-495-5 Chapter 1. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a108.zip --------------------------------------------------------------------------- 9600 Baud Packet Radio Modem Design Papers of ARRL 7th Computer Networking Conference (US), Oct 1988. pps 135- 140 Also: Proceedings of the first RSGB Data Symposium, Harrow, England July 1988. (12 pps). Also: "Packet: Speed, More Speed and Applications", ARRL 1995. ISBN 0-87259-495-5 Chapter 1. The theoretical minimum audio bandwidth required to send 9600 baud binary data is 4800 Hz. Since a typical NBFM radio has an unfiltered response from zero to some 8 kHz, transmission of 9600 baud binary data is perfectly possible through it. This paper describes a successful implementation. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a109.zip --------------------------------------------------------------------------- The Earth Moved Oscar News (UK) 1994 Apr No. 106 p8-9 The Earth does not appear to in a fixed position as seen from the Moon. Shows the wander, and discusses the implications for Lunar stations. Also: Amsat-VK Newsletter No. 108, 1994 April pps 7-8 It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a110.zip --------------------------------------------------------------------------- PLAN-13 Satellite Position Calculation Program Oscar News (UK) 1990 Oct No. 85 p.15-25 (See also 1983 Dec) - The basic routines needed for satellite calculations. Includes fundamental equations, explanation and heavily commented listing. Shows how to compute Orbit, MA, mode, range, azimuth, elevation, squint, range rate, doppler shift, height, sub-satellite point, footprint circle, day numbers, dates, Sun's position, solar azimuth, solar elevation, illumination, eclipses, visibility etc etc. Routines widely used by other authors. Booklet available, $10 US. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a111.zip --------------------------------------------------------------------------- Sun's Up Part 1 Oscar News (UK) 1984 Dec, No.50 p.2-6 Sun's Up Part 2 1985 Feb, No.51 p.2-6 Sun's Up Part 3 1985 Apr, No.52 p.8-11 Comprehensive series describing the Sun's orbit, how it's modelled, and its influence on satellite illumination (esp. AO-10), including eclipse prediction. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a112.zip --------------------------------------------------------------------------- Sensorship - A Question of Attitudes Oscar News (UK) Part 1 1985 Aug, No.54 p.2-8 Part 2 1985 Oct, No.55 p.2-5 Comprehensive series about spacecraft attitude determination, with particular reference to AO-10 Sun and Earth sensors. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a113.zip --------------------------------------------------------------------------- The Re-Entry of Oscar-13 1994 Oct No. 109 p 16-20 Without an atmosphere, Oscar-13 would collide with the Earth's crust on 1997 Feb 03. But we do have an atmosphere, which means that the satellite experiences a gradual retardation every perigee pass. Thus re-entry will be sooner, approximately 1996 Dec 16. This paper outlines the computer program and discusses the circumstances. Also: Proceedings of the 12th annual Amsat Space Symposium, Orlando, Florida, USA, 1994. 4 pages. Also: Amsat-DL Journal (D), Jg. 22, No. 1, Mar/May 1995. Also: Jamsat Newsletter (JA) No. 166, 1995 March 25. p1-4 Also: Amsat OZ Journal (OZ) No. 37, 1995 May Also: Amsat Journal (USA) Vol 18 No.3, May/June 1995. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a114.zip --------------------------------------------------------------------------- Mode-S - Tomorrow's Downlink. Oscar News (UK) 1992 Oct No. 97 p20-22 Proposes the abandonment of 145 MHz for P3 satellite downlinks, and shows why the logical choice is 2400 MHz. Also: Amsat-DL Journal Dec 1992 Nr4. Jg.19 Also: Amsat Journal (USA) Vol15 No. 5, 1992 Sep/Oct, p.14-15. Also: Amsat-VK Newsletter (VK), No. 90, September 1992 Also: CQ-DL 9/93 1993 September, p.614-617. Also: 73 Amateur Radio Today (USA), Issue #492, 2001 Nov, p.50-51 It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a115.zip --------------------------------------------------------------------------- A 60 cm S-Band Dish Antenna. Oscar News (UK) 1993 Apr No.100 p6-10 "Mode-S - Tomorrow's Downlink" proposed the abandonment of the 145 MHz band for weak signal amateur satellite downlinks and sparked off much interest. I explained why S-band (2.4 GHz) is unrivalled on every count as its replacement, and described in outline a tiny 60 cm diameter dish that is entirely adequate for Oscar-13. I many requests for more details. This antenna is simple and entirely adequate for Oscar-13 reception. Also: The Amsat Journal (USA) Vol 16 No. 2, March/April 1993. Also: Amsat-DL Journal (D), Jg. 20, No. 2, Jun/Aug 1993. Also: Amsat-VK Newsletter No. 97, 1993 April It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a116.zip --------------------------------------------------------------------------- A 16 turn S-band helix antenna Oscar News (UK) 1993 Oct No.103 p20-21 Entitled: Small iS beSteSt Also: Satellite Operator No. 33, June 1993. update ? Also: The Amsat Journal (USA) Vol 16 No.4, Jul/Aug 1993. Update Nov/Dec 93 Also: Amsat-VK Newsletter No. 99, 1993 June, update No. 102, 1993 Oct It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a117.zip --------------------------------------------------------------------------- Managing Oscar 13 Part 1 Oscar News (UK) 1993 Dec No.104 p16-21 Managing Oscar 13 Part 2 Oscar News (UK) 1994 Feb No.105 p18-23 Comprehensive discussion of all aspects of the subject. Also: Proceedings of the 11th annual Amsat Space Symposium, Dallas Texas, USA, 1993. 10 pages. (First placement). Also: Satellite Operator No. 37, October 1993. p46-55 Also: Amsat-VK Newsletter No. 104/5/6/7, 1993 Nov - 1994 Feb Also: The Amsat Journal (USA) Vol 17 No. 1, Jan/Feb 1994. Also: Amsat-DL Journal (D), Jg. 21, No. 2, Jun/Aug 1994. Also: Jamsat Newsletter (JA) 1994 Mar - 1995 May Also: BelAmsat Newsletter (ON) 1994 Dec; reprints of Oscar News and A-DL. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a118.zip --------------------------------------------------------------------------- An S-Band Beacon Oscar News (UK) 1994 Dec No. 110 p 6 Review of the SSB Electronic S-band beacon that you can use to check if your satellite (2.4 GHz) S-band receive system is working. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a119.zip --------------------------------------------------------------------------- Measure AO-13 Squint Directly! Oscar News (UK) 1993 Feb No. 99 p26-28. Shows how to calculate squint angle directly from S-band beacon. The AO-13 S-band antenna is offset from the spin axis, so range oscillates back and forth once per revolution. Hence the beacon warbles a few Hz, proportional to the magnitude of the squint angle. Also: The Amsat Journal (USA) Vol 16 No. 1, January 1993. Also: Amsat-DL Journal (D), Jg. 20, No. 1, March 1993. Also: Amsat-VK Newsletter (VK), No. 94, February 1993 It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a120.zip --------------------------------------------------------------------------- From Hardware to Vapourware; AO-13 Re-entry Plans Oscar News (UK) 1996 Jun No. 119 p 36-41 The presence of Earth's atmosphere at perigee robs AO-13 of energy, which is dissipated in the form of heat. This will cause burn-up around mid- December 1996. End-of-life effects are discernible as a) orbital period decrease and b) changes of attitude, c) heating. The first two are already observable. Aspects of AO-13's re-entry are explored in these notes. In particular a re-orientation to the unfamiliar attitude Alon/Alat = 90/0 is proposed from mid-August 1996. Also: The Amsat Journal (USA) Vol 19 No.4, Jul/Aug 1996. Also: Amsat-VK Newsletter No. 135/136, 1996 Jul/Aug Also: Amsat-DL Journal (D), Jg. 23, No. 3, Sep 1996 Also: Jamsat Newsletter (JA) No. 176, 1996 Aug 30 It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a121.zip --------------------------------------------------------------------------- Oscar-13's Life and Death Oscar News (UK) 1997 Feb No.123 p 24-29 Oscar-13 was launched from Kourou on 1988 Jun 15th on the first test flight (V-22) of the Ariane 4 rocket, along with Panamsat and Meteosat P2. Eight and a half years later AO-13 re-entered and burned up, on 1996 Dec 5th. Also: The Amsat Journal (USA) Vol 20 No.2, Mar/Apr 1997 Also: Amsat-DL Journal (D), Jg. 24, No. 1, Mar/May 1997 Also: Jamsat Newsletter (JA) - In preparation It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a122.zip or the www presentation: http://www.amsat.org/amsat/articles/g3ruh/122.html --------------------------------------------------------------------------- Phase III Ranging System Oscar News (UK) 1997 Sep No.126 Also: The Amsat Journal (USA) Vol 20 No.5, Sep/Oct 1997 Also: Amsat-DL Journal (D), Jg.25, No.1, Mar/May 1998 Also: Jamsat Newsletter (JA) No. 197, 2000 Oct Ranging is the process of measuring the distance from a station to a satellite. Ranges made at different times, and from several locations are used to determine the specifics of an orbit and compute Keplerian elements. P3D, like its predecessors P3A, Oscar-10 and Oscar-13 is supported by ground station software and hardware to enable this. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a123.zip or the www presentation: http://www.amsat.org/amsat/articles/g3ruh/123.html --------------------------------------------------------------------------- The Experimental IHU-2 Aboard P3D Co-authored by Chuck Green, Peter Gülzow, Lyle Johnson, Karl Meinzer and James Miller Proceedings of 13th Amsat-UK Colloquium 1998, Guildford Surrey, England. pps 128-138 Also: Proceedings of the 16th annual Amsat-NA Space Symposium, Vicksburg, Mississippi, USA, 1998. pps 142-152. Also: The Amsat Journal (USA) Vol 22 No.2, Mar/Apr 1999 Abstract IHU-2 is intended to act as a future replacement for the current COSMAC- 1802-based flight computer (IHU) that has flown on all previous P3 missions and indeed controls the AMSAT P3D satellite. The IHU-2 is aboard P3D as a proof-of-technology experiment. Although in contact with other P3D sub- systems, it will not manage anything mission critical. These notes document the design from inspiration in September 1997 to running hardware/software, April 1998. It is available on-line as the file: ftp://ftp.amsat.org/amsat/articles/g3ruh/a124.zip or the www presentation: http://www.amsat.org/amsat/articles/g3ruh/124.html --------------------------------------------------------------------------- Oscar-40 FEC Telemetry Amsat-UK's Oscar News, 2003 Aug No.161 p.18-22 Also: The Amsat Journal (USA) Vol 26 No.5, Sep/Oct 2003 Also: Amsat-DL Journal (D), Jg.30, No.4, Dec/Feb 2003/2004 Also: Amsat-OZ Journal (DK) No.125 September 2003 Also: Amsat-SM Info (S) Nr.2 August 2003 Also: Jamsat Newsletter (JA) In prep. 2003-Sep Summary Phil Karn KA9Q has long argued that Amsat should adopt the communication strategies used routinely for several decades by NASA space missions. They have now been implemented experimentally on Oscar-40. The results are truly spectacular. Indeed we must surely adopt strong Forward Error Correction (FEC) by default on future missions. This article describes the system, and presents results with AO-40. Using FEC, if you can hear it, it decodes; error-free! It is available on-line as the www presentation (only): http://www.amsat.org/amsat/articles/g3ruh/125.html --------------------------------------------------------------------------- Control Software for the Bochum Radio Telescope The Amsat Journal (USA) Vol 28 No.6, Nov/Dec 2005 Also: Amsat-DL Journal (D), Jg.31, No.3, Sep/Oct 2005 (Similar article) Abstract Every ham secretly wants to play with a really big antenna ... I got my chance! The restoration of this 20m diameter antenna required a new control system. The author was invited to write the software. This article describes its evolution. It is available on-line as the www presentation (only): http://www.amsat.org/amsat/articles/g3ruh/126.html --------------------------------------------------------------------------- (4) AO-13 Telemetry =============== Daily Oscar-13 telemetry is archived together with support files as follows: directory: amsat/satinfo/ao13 ------------------------------ 00README.TXT General info decaykep.zip AO-13 future 2-line keplerian elements up to re-entry + pictures, tables, telemetry etc schedule.doc Current AO-13 transponder schedule spec_tlm.doc Full AO-13 telemetry specification spec_wod.doc Format of whole orbit dump K and L blocks spec_crc.doc P3 telemetry CRCC specification events.doc Explanation of Event flags demod.zip MK II Decoder spec, ordering, sources, MK I mods. telemetry Sub-directory - see below Sub-directory: amsat/satinfo/ao13/telemetry -------------------------------------------- Annual telemetry: 88.zip AO-13 Telemetry 1988 89.zip 1989 . . . . 94.zip 1994 and then monthly: 9405.zip 1994 May 9406.zip Jun etc etc 9611.zip 1996 Nov (burned up 1996 Dec 05) To display this telemetry data you need software such as P3C.EXE or P3TLM for the IBM-PC, !TLM13 for Acorn Risc Computers and so on. (Note: No decoder hardware is required to display files). (5) Public Notice ============= These articles/notes etc are herewith placed in the public domain. They may be reproduced at will in any "not for profit" medium, provided credit is given to the author and original publisher. If you wish to use the material in a "for profit" manner, please contact the author first and consider a donation to AMSAT for each copy sold. The papers are observations of the author alone, and do not represent the policy or opinions of Amsat, Amsat-UK or any other organisation. I disclaim all responsibility for any loss or damage, direct or indirect arising from use or abuse of this material. James Miller G3RUH Personal WWW: http://www.jrmiller.demon.co.uk/