Manual for preparation of the Main Telemetry Station and Experimenters Room for Student Rocket Operations

Main Telemetry

Station Manual

1. Introduction

At Andøya Rocket Range (ARR) we use two telemetry stations for receiving and processing data from student rockets. The Main Telemetry station (or Main TM station) uses a 10’ and a 20’parabolic antenna for receiving signals from the rocket.These antennasare commonly used by ARR during scientific rocket campaigns. During the student rocket campaign some of theMain TM station will be set up and operated by ARR staff, and some of the preparations will be done by students under supervision of the group leader. The Student telemetry station is used as back-up during student rocket campaigns, and for educational purposes in off-campaign matters.

Figure 1showsatypicalblockschemeforatelemetrystationwiththemostimportantequipmentneededtoreceiveandprocessdatafromasoundingrocket.Thismanualwillgiveadescriptiononhowtosetupthemaintelemetrystationsforastudentrocketlaunch.Anintroductiontothemaincomponentsofatelemetrystationwillbegivenbeforethetelemetrystationsareprepared.

Figure1

2. Main telemetry station

Preparationofthistelemetrystationiscomprehensiveandoperatorsundercampaignshavelotsofexperienceandknowledgeabouttheequipmentinthestation.Inthefollowingwewillseehowtosetupsomeofthestationtoreceiveandprocessdatafromthestudentrocket.

2.1Receiver setup

Therearetwo Microdyne 1100 receivers (Figure 2)intheMaintelemetrystation.Oneforright-handcirculatedpolarized (RHCP) signals,andoneforleft-handcirculatedpolarized (LHCP) signals.The10’ antennareceivesbothkindsofsignalson 2279.5 MHzfromtherocketantennas.Onthe 10’ antennapedestalthefrequencyisdownconvertedwithafrequencyof 1985 MHz.Subtractthisfrequencyfromthereceivedfrequencyandsetthereceivertotherightfrequency.AttheMain TM weusuallyusemorereceiversforback-up.The Multicouplers aresignaldistributorstothedifferentreceivers.Alwaysremembertoswitchthe multicouplers onwhenweusethereceivers.Other receiverfunctionswillbeexplainedbyyourgroup leader.

Tasks:

  • Switch on both multicouplers.
  • Switch on all receivers.
  • Tune in to the correct frequency.
  • Make sure the demodulation is set to FM.
  • Set 2nd LO mode to XTAL.
  • Set AGC Time Constant to 100 ms

For the 1400 receiverselect:

  • Bandwidth to 2Mhz
  • Video bandwidth 500kHz
  • Loop bandwidth to 20 (by pushing the arrow symbol)
  • Antisideband to 3 (by pushing enable button)

Figure 2

Microdyne 700-MRB Receivers

Thereceiversneedtobeconfiguredaccordingtothesignalsfromtherocketpayload.

Frequency

  1. SetRF FREQ to “294.5 MHz”.ThisisthesamefrequencyastheTransmitter(Tx)intherocketpayload.
  2. SetIF BW to “2.4 MHz”.Bandwidthoftheintermediatefrequency(IF).
  3. Set B/S to“NO Bs/Sc”. Becausethereareno Bitsync inthereceiver.
  4. Set RCD FREQ to“NoPre Det”.
  5. SetVID BW to “500 kHz”
  6. Set 2ndLOto “.0 K”

Demodulation

  1. SetFM BW to “100 4 FM”. (increase to 1.25 MHz “100 3 FM if no sync)
  2. SetLoop BW to “100 4 FM” . (increase to 1.25 MHz “100 3 FM if no sync)
  3. SetSWEEP RNG to “250 kHz”.

Other parameters

  1. Makesure 2nd LOmodeissetto “XTAL”.
  2. MakesureAGC TC issetto “100 ms”.
  3. MakesureSWEEPENison.
  4. MakesureVIDGAINisbetween -15 dBand -20 dB.

- Microdyne1620-PCR Diversity Combiner

The main tasks of the combiner are to pass on the best signal from the receivers (LH or RH) and to reduce various unwanted signal effects like modulation, polarization and distortion.

Frequency

  1. SetIFMONto “2.4 MHz”.Thisisthefrequencyreceivedfromthereceivers.
  2. Set B/S to“NO Bs/Sc”. Becausethereareno Bitsync inthereceiver.
  3. Set RCD FREQ to“NoPre Det”.
  4. SetVID BW to “500 kHz”
  5. SetCombLOto “.0 K”
  6. Set Demod LOto “.0 K”

Demodulation

  1. SetFM BW to “100 4 FM”.
  2. SetLoop BW to “100 4 FM”
  3. Set Demod Modeto “100 4 FM”

2.2Bit Synchronizer

The Bit Synchronizer locks on to the bit stream from the combiner and give out NRZ-code and clock (CLK).

Tasks:

  • Switch on Bit Synchronizers
  • Set bit rate to: 256 kbit/s
  • Set code to: Bi-Phase – L (Biφ-L)
  • Make sure Data Polarity is set to Normal, Detection is set to I/D, Loop Width is set to 0.3% and that channel 1 is used.
  • Select source:1

2.3Patching

Instead of using cables from and to every single component in the TM station and other stations at ARR, we use the two patch panels to connect the different components to each other. An overview of the patch panels and how to patch signals are described in the Appendix 1 and 2. In brief, patching signals includes:

-Data to the different tracks on the tape recorders. Group leaders will give an introduction to which signals to be recorded.

-Signals from either Combiner or Bit Synchronizer to one or more Eidel PCs in Experimenters room.

-SignalsaccordingtotheblockschemeinFigure 1.

Do not hurry with the patching. Let the whole group be aware of what signals to be patched. Your group leader will explain the signal patching in details.

It is important to be careful with the patching wires and when you put the patching plugs on the patch panel. The patching plugs are thin and break easily.

Tasks:

  • Use Appendix 1, 2 andFigure 3 topatchsignalsonpatchboard 1 and 2.

2.4Format set up on VTS.

ThePCMformatneedstobesetupontheVisualTestSystem (VTS) Computer.Theprincipleisthesameasfor EE315 butthe VTS ismorecomplex, sothe setup on VTS willbedemonstratedbythegroupleaderorARRstaff.

2.5Slant range calculations

Slant range is the method of calculating the flight profile of the rocket. This is usually done in a different station at ARR called Trajectory and Position System (TPS), but it needs information from the Main TM to do this calculations. The group leader will explain this in brief at the station.

Figure 3

Experimenters room setup

Patching from Main TM to the experimenters room are a part of the fixed setup at ARR. Signals may also be patched to the different experimenters desks through patch panel 1. The number of computers used in the Experimenters Room varies from campaign to campaign, and how many experiments that needs to be monitored.

Tasks:

  • Make sure the Line Drivers and Word Selectors in the Main TM are switched on.
  • Patch output signals (NRZ and CLK) from the different desks to the respectively computers in the experimenters room.

3.1The student rocket PCM format.

To visualizedatafromtherocketARRusestheEidel software and VisualTelemetrySystem (VTS). Before we can set up the computers we need to know the format is generated in the rocket payload PCM encoder. The format is shown in Table 1.

Bitrate / 256 kbit/s
PCM code / BiPhase-Level (Biφ-L)
Sync-word / 16 bit, hex:EB90, bin:1110 1011 1001 0000
Frame counter / 16 bit (Word 02 is MSB, Word 03 is LSB)
Words per Frame / 14
Frame per Format / 1
Analogue channels / 8
Analogue word length / 8 bit
Digital channels / 2
Digital word length / 8 bit

Table 1

Datafromtherocketarecodedbytheencoderintherocketpayload.ThiscodeiscalledPulseCodeModulation(PCM).Thiscodehastobedecodedbythevisualizationsoftware.ThePCMcodeforthestudentrocketis Biφ-L. Howthisandanothercodecalled NRZ representbinarycodesareshowninFigure 4.

Figure 4

DetailsofthedifferentwordallocationofthePCMformatareshowninTable 2.

Word / Allocation / Data / Comment
00 / Frame Sync (EB)
01 / Frame Sync (90)
02 / Frame Counter MSB
03 / Frame Counter LSB
04 / Analogue Ch 0 / Temperature PCB-card
05 / Analogue Ch 1 / Temperature Nose
06 / Analogue Ch 2 / Magnetometer / Spin
07 / Analogue Ch 3 / Pressure Sensor
08 / Analogue Ch 4 / AccelerometerZ
09 / Analogue Ch 5 / Accelerometer Y
10 / Analogue Ch 6 / Photo Transistor
11 / Analogue Ch 7 / Payload Battery Voltage
12 / Digital Ch 0
13 / Digital Ch 1 / First bit pulled high at lift-off

Table2

3.2Format set up on Eidel (EE315-DOS version and EE350-Windows version)

Someofthe Eidel cardatARRcomeswithintegratedBit Synchronizer (BitSync)andsomedoesnot.ComputerswithintegratedBitSyncwillhaveinputsignalsdirectlyfromthe combiner(orfromthe Biφ-L outputfromtheBitSync). Eidel cardswithoutBitSyncwillofcoursehaveinputsignalsfromanexternalBitSync.Thecomputersinthe Experimenters Roomcomewithdifferentversionsofthe Eidel software.Thefollowingchapterillustratestheprocessof Eidel setupinbrief.Fordetailsaboutthe Eidel softwarewerefertothemanualsthatyouwillfindinthe Experimenters Room.

Runtheprogramandchoosethe“Format Setup”. SetthecorrectparametersaccordingtoTable 1.Figure 5 showsanexampleoftheformat setup in EE315. Donotusetheparametersinthe figure.

Figure 5

Choosethe“Data Setup andDisplay”on EE315 or“Signal Setup” on EE350 tosettherestoftheparametersinTable 2. Setupyourdisplaysinsuchwaythattheanaloguechannelsfirstshowitsdecimalvalue, andthenthespecialscalevalue.(NB!In EE315 thespecialscaleeditcomesupifyoupush F9). Thespecialscalevaluereferstothesensorsvoltageoutputlevel.Thisvoltagehastobeconvertedtoadifferentvalue, e.g.bar, meter, g, teslaor gauss. Tovisualizethesensoroutputinaspecialscaleyouwillneedtoputinsomescalingformulas.Calculationoftheseformulasmustbebasedonthebitresolutionandsensoroutput.Thus, studythedifferentsensordatasheetsandtrytofigureoutwhattheformulameans.ThedifferentformulasandconstantsarelistedinTable 3.Notethattheseformulashavetobecalibratedwhenthepayloadandexperimentalgrouparefinishedwiththesensors.

During thepayloadtestingyouwillseeifthe Eidel computersarecorrectconfigured.ShowtheExperimentalgrouphowtheycanmonitortheirsensorsduringthecampaign.

  1. Readyforcampaign

DuringthefinaltestingyouwillseeiftheMain TM stationandthe Experimenters Roomareworkingproperly.Ifnot, youwillhavetogothroughthewhole setup togetherwithyourgroupleader, andtroubleshoot.

Goodluckonthecampaign!

Amund Nylund and Kjetil HenninenPage 1of12

Last update: 15.10.2006

Manual for preparation of the Main Telemetry Station and Experimenters Room for Student Rocket Operations

Sensor / Formula / Scale name / Notes / Scale Min value / Scale Max value / Low limit / High limit / Constants
TemperaturePCB / ((A/e)*g)/f / C (Celcius degrees) / f = 0.05 / -10 / 120 / 0 / 100 / A = wordnr
e = 256
f = seenotes
g = 5
h = 44307.69396
i = 38*10-3
j = 0.190284
k = 130
l = 3.2
m = -0.48 [1]
n = 0.0045
o = 5
TemperatureNose / ((A/e)*g)/f / C (Celcius degrees) / f = 0.05 / -10 / 120 / 0 / 100
MagneticField / ((A/e)*g)*o / kA/m [2] / Optional[3] / -10 / 10 / -10 / 10
Pressure / (((A/e)*g)-m)/n / mbar (millibars) / Optional[4] / 0 / 1100 / 0 / 1015
Acceleration Z / (((A-k)/e)*g)/i / g (m/s2) / -60 / 60 / -50 / 50
Acceleration Y / ((A-k)/e), k=A(0), e=16 / g (m/s2) / -5 / 5 / -2 / 2
Photo Transis. / ((A/e)*g)*l / Intensity
BatteryVoltage / ((A/e)*g)*l / V (Volts) / 4 / 16 / 5.2 / 12
Altitude / h*((1-((((A/e)*g)-m)/n)^j) / m(meter) / 0 / 10000 / 0 / 9000
BatteryVoltage / ((A/e)*g)*l / V (Volts) / 4 / 16 / 5.2 / 12
Umbilical / A / IN(markslift-off) / Maskfirstbit / 0 / 1 / 0 / 1

Table 3

Amund Nylund and Kjetil HenninenPage 1of12

Last update: 15.10.2006

Manual for preparation of the Main Telemetry Station and Experimenters Room for Student Rocket Operations

Appendix 1

Patching board nr 1

1K– 9L
1S – 10E / 6Q – 2R / 11A–12J
11B–12P
11C–12Q
11E–20L
11F–15W
11H – 15S
11J – 10N / 20J – 9V
20K – 14S
20L – 11E
2K – 9N
2R– 6Q
2S – 10G
2X –21C / 7E – 10A
7A – 18A
7J –23K / 12G – 9A
12J – 11A
12P – 11B
12Q–11C
12U -9C / 21A – 15R
21B – 15V
21C – 2X
3M – 10L / 8J – 23H / 14S – 20K / 23K– 7J
23L–15Q
23H – 8J
23J –15U
4C –9G
4K – 10C
4R – 5S / 9A –12G
9C – 12U
9G –4C
9J – 18C
9L – 1K
9N –2K
9Q–15X
9V –20J
9W–15T / 15Q – 23L
15R – 21A
15S – 11H
15T – 9W
15U –23J
15V –21B
15W –11F
15X – 9Q
5A – 18B
5Q – 10K
5S – 4R / 10A –7E
10C – 4K
10E – 1S
10G – 2S
10K – 5Q
10L – 3M
10N – 11J / 18A–7A
18B-5A
18C–9J

Figure 6 – Patch board nr 1 /
Figure 7 – Overview patch board nr 1

Appendix 2

Patching board nr 2

1E – 4C
1U – 2E
1S – 5Q
1T – 1W
1W – 1T
2E – 1U
3F-8A / 6Q – 4R
7F - 16T / 11J – 20U
4C – 1E
4E – 8E
4R – 6Q
4S – 5S
4T – 9V
4U – 9W
4V – 9Q
4W – 12G
4X – 12Q / 8A – 3F
8E – 4E
8F – 5V / 12G – 4W
12H-20T
12Q – 4X / 20T – 12H
20U–11J
5Q – 1S
5S –4S
5V – 8F / 9Q – 4V
9V – 4T
9W – 4U / 16T - 7F

Figure 8 – Patch board nr 2 /
Figure 9 – Overview patch board nr 2

Amund Nylund and Kjetil HenninenPage 1of12

Last update: 15.10.2006

[1]This valuemustbecorrectedforthebarometricpressureatlauncherduringtherocketcampaign.Thecorrectionformulaisbasedonthelinearscalepressureoutputfromthepressuresensor datasheet. Thisformulais:m = ((Output voltage) – 0.0045*(Known Pressure))

[2]1 kA/m = 1.25 mTesla (inair), 1 mT = 10 Gauss. Inthisformulathevalueisnotconcurrentwithunits.

[3]Themagnetometerusedonthissensorisonlytoregisterrocketspin variations.

[4]Altitudeiscalculatedfromthepressure value.