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moon flyby sat
« : 23. Listopad. 2014, 17:15:09 »
Pass the word to all who have 2m SSB and WSJT capability with an antenna
 that can point to the moon:

 Tonight a rocket will launch from China carrying an amateur radio
 payload. The payload was designed and built by LX0CHB.
 Here are the details about the payload and the mission followed by
 details about the contest:

 LuxSpace -- 4M / LX2RG     4M Mission: a Lunar FlyBy experiment
 G. Ruy, J. Harms, H.Moser, B.vanSchie, J.Buursink, Ph.Ries
 1LuxSpace Sarl, SES Business Center, 9, rue Pierre Werner, 6832
 Betzdorf, Luxemburg

 The 4M mission is an opportunity mission, in honor of late Professor
 Manfred Fuchs, founder of the OHB group. 4M means: Manfred Memorial Moon

 The project is conducted by LuxSpace, Grand Duchy of Luxembourg and is a
 quick, low cost mission aiming at global cooperation whilst presenting
 challenges opening new ways.

 Mission description
 The spacecraft will be part of the last stage of a lunar mission, due to
 be launched end of October 2014.
 *The launch of the 4M mission is confirmed tonight the 23rd at 17:59 UT*
 The trajectory will be a lunar flyby and return to Earth, with 90%
 chances of re-entry in the atmosphere. The 10% remaining chances lead to
 a very interesting orbit. The nominal mission duration is 196 hours,
 *8.17 days*. The Lunar flyby will occur 97 hours after injection, 4.04 days.
 During flyby, the range to EU stations will be 399636km at most and the
 distance to the Moon will be between 12000 and 24000 km depending on the
 final injection vector.

 The 4M spacecraft will transmit continuously on 145.980MHz (+/- 2.9kHz)
 with a 1.5W power input at antenna which is a simple Monopole.
 This will give S/N comparable to EME signals at Earth's surface.
 The transmission is based on a 1 minute sequence and a 5 minutes cycle.
 *The transmission will start 4670s (77.8 minutes) after launch (-0, +600s)*

 The spacecraft is comprised of the following equipment:
 - Primary power source: 28 high energy density, non rechargeable cells,
 guaranteeing the nominal mission whilst providing 6W to the payloads.
 - Secondary power source: 2 x 8 Triple layer solar cells and 4 x Li-Ion
 rechargeable cells.
 - An Onboard Computer, FM430 and interface board
 - An I/Q modulator
 - An RF power amplifier, providing a nominal 1.5W into the antenna
 - An L/4 antenna
 - RAD experiment fro radiation dose determination on the trajectory
 The RAD experiment is a special chip from IC-Malagua (Spain), that is
 able to accurately measure the Radiation dose rate.

 Trajectory description
 _The injection will occur over the Pacific Ocean and only Eastern
 Australia / New Zealand stations will be able to receive the 4M S/C._
 The 4M is on a "collision" course with the Moon for the FlyBy.
 The Moon will be at its lowest declination, to optimize the launcher

 Visibility during flyby 1hr after injection

 Visibility 6hrs after injection:

 Pointing of the antenna
 The problem to solve is that only nominal trajectory is known. The
 trajectory dispersion is also known. The actual trajectory will be
 comprised inside the limits.The purpose of this chapter is to examine if
 it is sufficient to point the antenna on the 'nominal' trajectory and
 verify that the extreme case (+/- 3 Sigma) trajectories yet allow the 4M
 to be inside the pattern of the antenna.
 The simulations have been performed with a 25° beamwidth.
 During the first part of the trajectory up to the Flyby, the nominal and
 max deviation trajectories are close one to each other, therefore, the
 nominal trajectory elements may be used.
 The dedicated website and Facebook pages will be updated as soon as the
 injection vector is known.
 For ease of use, tables will be published that will also indicate the
 Offset pointing in Az and El relatively to the Moon.

 After the FlyBy, the trajectory is much more difficult to predict due to
 the sensitivity of the elements, and the pointing may require some
 'search'. We shall endeavour to provide correct elements.

 Average case
 The average EIRP is -6dBW, actually depending on the orientation of the
 last stage and can vary from -30dBW to +5.5dBW.
 The required received signal is -158dBm assuming a system temperature of
 641°K. (roughly corresponding to 0.5dB losses and LNA = 1dB NF)
 *note from WA6KBL:  641K is around 5dB NF*

 Such conditions can easily be met with the following setup:
 Antenna: 12dBic, equivalent to a 12elements Yagi CP
 Losses before LNA: 0.5dB
 LNA: NF = 1dB
 *note from WA6KBL:  the 5dB includes lots of loss after the mast mounted
 LNA**and a poor receiver*

 Transmit sequence description
 To account for the various constraints, mass, size, power, link budget,
 available average receivng station, an EME mode was selected as the most
 appropriate way to transmit the data.
 The transmit cycle is organized in 5 consecutive, one minute sequences
 starting at 0s of the UTC minute.
 In addition, to fill in the 1 minute sequence, an additional "analog"
 sequence is added, that allows the detection of the transmission by
 longer integration, and provides for the basic data of the S/C.
 NOTE: the internal real time clock of the OBC may drift by several
 seconds, even minutes in the course of the mission, due to severe
 temperature variations.
 The Transmitter of the payload performs a 1 minute sequence on a 5
 minutes cycle starting on UTC hour, based on JT65B mode and 'human
 readable' tone transmissions according to the following sequence:
 Tableau 1 transmission sequence
 Time /s
 Frequency / data rate
 Duration / s
 First UTC second for JT65 is off
 Data area(*)
 m-FSK -- JT65B mode
 Digital data
 Call sign + data
 Unique tone 4
 400, 420, 440, 460, 480Hz (depending on which
 Start of digital sequence
 15 EME2014 -- LuxSpace -- 4M / LX2RG
 sequence is transmitted)
 Unique tone 1
 250 Hz
 2 s
 Start of sequence 1
 Variable tone 1
 500 -- 2500 Hz
 Battery voltage
 1Hz/10mV -- 0-20V max
 Unique tone 2
 300 Hz
 Start of sequence 2
 Variable tone 2
 500 - 2500 Hz
 OBC temperature
 13.33Hz/°C -- range: -50, +100°C
 There are 5 successive sequences that are transmitted in a 5 minutes cycle.
 The content of the analog sequence is the same in all sequences.
 JT65B data sequence
 The data content of the JT65B sequence is described in the following table:
 Tableau 2 JT65B sequence content Sequence number / start Description
 Experiment 1 / UTC + 0 m 00s Callsign RAD experiment is turned ON
 1 / UTC + 0 m 02s
 ( at the latest)
 RAD experiment sends Boot message 2 / UTC + 1 m 00s Telemetry of 4M: V,
 I, T 3 / UTC + 2 m 00s Global MSG transmission
 3 / UTC + 2 m 58s
 ( at the latest)
 RAD experiment sends its data and is turned OFF 4/ UTC + 3m 00s RAD
 experiment data transmission
 4 / UTC + 3m 02s
 ( at the latest)
 4 / UTC + 3m 58s
 ( at the latest)
 5/ UTC + 4m 00s Global MSG transmission
 16 EME2014 -- LuxSpace -- 4M / LX2RG
 The content of the JT65B sequences is described here after. Note that
 the CAM and RAD data are 'random' character in the allowable set of
 JT65B. (copy of the Text window of WSJT9) A00001 5 -22 -0.5 3 3 *
 LX0OHB-4M 1 0 // Callsign
 A00003 8 -23 -1.0 3 3 * 125V500A120C 1 0 // Voltage in 100mV, current in
 mA, Temp in°C
 A00009 4 -24 -0.9 -3 3 * HELLO WORLD P 1 0 // clear text messages, 4000
 different ones, sent 1 time each
 A00013 5 -24 -0.9 -5 4 * 3? 2AF6DDC9-/ 1 0 // RAD experiment data
 A00019 9 -22 -0.8 5 3 * Ni Hao XinHua 1 0 // CAM experiment data A00020
 5 -24 -0.8 3 2 * LX0OHB-4M 1 0 // new cycle begins
 The 'unique tone 4' may take 5 different values indicating which JT65B
 sequence follows.
 Analog sequence
 The analog sequence consist of three times two tones as per the
 following table:
 Frequency / datarate
 Unique tone 1
 250 Hz
 Start of analog sequence 1
 Variable tone 1
 500 -- 2500 Hz
 Battery voltage
 1Hz/10mV -- 0-20V max
 Unique tone 2
 300 Hz
 Start of analog sequence 2
 Variable tone 2
 500 - 3000 Hz
 Battery temperature
 15Hz/°C -- range: -50, +117°C
 Unique tone 3
 350 Hz
 Start of analog sequence 3
 Variable tone 3
 500 - 3000 Hz
 Unique tone 4
 400, 420, 440, 460, 480Hz (depending on which sequence is transmitted)
 Start of digital JT65 sequence
 Data area (*)
 m-FSK -- JT65B mode
 Digital data JT65B
 See description above
 1 minute cycle
 400Hz: Seq 1420Hz: Seq 2440Hz: Seq 3460Hz: Seq 4480Hz: Seq 5
 17 EME2014 -- LuxSpace -- 4M / LX2RG
 Analog sequence demodulation
 The analog sequence is modulated in DSB, SC, allowing for stations with
 non accurate receiver to determine the value of the telemetry by
 measuring the spacing between the peaks of the FFT.
 However, even in SSB, recording the signal for several minutes allows a
 rapid identification of the sequences.
 This will allow also to identify the Unique Tone 4 that indicates the
 start of the JT65B sequence.
 Assuming a sample rate of 11025s/s, the duration of each tone allows a
 16k (0.673Hz BW) or 32k FFT (0.336Hz BW) which gives an 'eye' decoding
 increased performance of up to 9dB compared to JT65B. Average should be
 rather on 3 to 6 dB improvement, mainly depending on the angular speed
 of the 4M S/C. (Doppler 'jitter') and its relative orientation.

 Use WSTJ10 decoding software (and associated requirements)
 Use latest release that includes special feature for 4M.
 Spectrum Lab recording and time stamping software:
 Spectrum Lab is a widely used and highly practical software that allows
 recording and time stamping signals. More over, it allows to 'chunk' the
 recordings into predetrmined lengths, and automatically naming the
 recordings with the time stamp.
 NOTE: be careful with the time zone settings of your computer in
 programming Spectrum Lab file naming.

 The next figure is a screen capture of a complete sequence with SpectrumLab:

 In the bottom, on can see the 440Hz Unique tone 4, followed by the JT65B
 transmission, and the 'analog ' sequence on top of the screen.
 The same sequence with Adobe Audition:

 Experiments and mission
 Given the trajectory and visibility, it is clear that all around the
 world OM stations are needed in order to have data continuity.
 Several 'experiments' are ran in parallel in this mission and need the
 collaboration of as many stations as possible.
 One contest is organized for each experiment in multiple catgories,
 single station, cooperative group.
 For experiment 1 and from the visibility patterns, one significant group
 may consist of at least a station in Australia/New Zealand/New Caledonia
 area, one in the American continent, and one in the Western Europe/
 Africa area.
 For the experiment2 , one significant group may consist of at least 4,
 better five stations, in common visibility of the 4M spacecraft.
 For contest 3, individual stations may compete, although, as for
 experiment 1, groups are also welcome.
 Experiment One
 Experiment One consists in retrieving a continous set of data of
 telemetry for the RAD experiment.
 The data of the RAD experiment do not absolutely need to be contiguous.
 The RAD experiment transmits the dose rate at the time of measurement.
 The 4M spacecraft will be subject to a total dose of 74 to 100 kRads
 during the mission and a dose rate of 13 to 16 Rads / hour.
 Further information wil be published on how to send the collected data.
 It will be based either on the copy of the relevant line or text zone of
 WSJT9 and sending it to a dedicated eMail address along with the
 timestamp of reception (to within a minute). Either by installing a
 small java client that will automate the process.The amount of data is
 quite small.
 Experiment Two
 Experiment Two is a more challenging one as it will use TDOA (aka
 'MultiLateration', ) method
 to determine the position of the spacecraft.
 At least 4 simultaneous measurement are needed. The principle relies on
 the time stamping of the recordings on the Call sign sequence using
 Spectrum Lab software. As the CallSign sequence is known, a correlation
 will be made between the 4 (at least) recordings to determine the Time
 Difference Of Arrival of the call sign sequence.
 Using the measured TDOA, the position of the S/C can be determined.
 The PC's clock should be sync'ed to within 1ms of the Internet time. 1ms
 represents 300km transit time or error in this case. The stations shall
 be clearly identified by accurate Altitude (WGS84) Latitude and
 Longitude to within 1km or better.
 We do not expect a high accuracy of the position, somewhere around
 5000km, depending on the accurate settting of the various PC's clocks
 and the geometry between the 4 stations and the 4M S/C.
 It is to be noted that this technique also allows to compute the
 position of the Moon in casual EME operation !
 Contest 3
 The 4M S/C shall transmit approximately 2500+ different messages, that
 are pre recorded in its memory.
 The OM's, or constituted group that collects the biggest number of
 messages will be declared the winner of the contest.
 Contest 4
 We need the telemetry of the 4M S/C to assess its success.
 *The OM, or constituted group that collects the biggest number of
 telemetry points will be declared the winner of the contest.*
 It is to be noted that the use of the "analog" sequences is encouraged,
 and allows even 'small' stations to participate.
 **The Contest*

 LuxSpace will offer attractive prizes to the winners in each experiment
 and category.
 The prizes will be attributed in the following categories:
 Experiment 1 Individual
 Experiment 1 constituted group
 Experiment 2 constituted group
 Contest 3 individual
 Contest 3 constituted group
 Contest 4 individual
 Contest 4 constituted group

 Manually :How to copy WSJT9 Text data zone
 Select all the text in the 'Decoded' window, Ctrl-C and paste in a .txt
 file. This should give a result like the one shown hereafter:
 A00001 5 -22 -0.5 3 3 * LX0OHB-4Mxxxx 1 0
 A00003 8 -23 -1.0 3 3 * 125V500A120Cy 1 0
 A00009 4 -24 -0.9 -3 3 * HELLO WORLD P 1 0
 A00013 5 -24 -0.9 -5 4 * 3? 2AF6DDC9-/ 1 0
 A00019 9 -22 -0.8 5 3 * Ni Hao XinHua 1 0
 A00020 5 -24 -0.8 3 2 * LX0OHB-4M 1 0
 Please note that xxxx and y are mission related parameters, the value of
 which will be published later.
 Simpler Alternative
 Send daily the ALL.TXT by mail to the eMail address that will be
 provided on our facebook page.
 21 EME2014 -- LuxSpace -- 4M / LX2RG
 Automated client
 The OM's at LSE Space application are developing a smal Java client that
 you can download and install. It will connect to
 our database, and after your authorization will automatically send the
 ALL.TXT and the decoded.txt to our database.
 In addition, should you wish to do so, you can also allow sending of the
 .wav files that are recorded by WSJT (only
 decoded ones).
 Everything is under your control.
 Client (prototype snapshot - 1)
 Client (prototype snapshot - 2)

 Here is the URL for the complete WSJT decoding and time calibration

 This contains the instructions for sending your reports.

 Be ready before the launch. The trip to the Moon lasts only 96 hours.

 Try your procedures beforehand so as to be QRV in time.
                     //info from 50mhz and up net, AD6IW