DSLWP Radio Info

DSLWP-A / Longjiang-1

BJ1SM

Downlink

  • Frequency
    • 435.425 / 436.425 MHz
  • Antenna
    • 2 × shortened monopole, 90° mounted
  • Polarization
    • Linear
  • Modulation
    • 250/500 bps GMSK with or without precoder
    • JT4G
  • Channel Coding (for GMSK)
    • 1/2 or 1/4 Turbo code
  • Randomizer (for GMSK)
    • CCSDS
  • Sync Word (for GMSK)
    • 0x034776C7272895B0 (1/2 Turbo)
    • 0x034776C7272895B0FCB88938D8D76A4F (1/4 Turbo)
  • Power
    • 33 dBm

Uplink

  • Frequency
    • VHF
  • Antenna
    • 2 × shortened monopole, 90° mounted
  • Polarization
    • Linear
  • Channel Coding
    • (7, 1/2) convolutional + (255, 223) RS
  • Modulation
    • 250 bps GMSK
    • DSSS-2FSK

DSLWP-B / Longjiang-2

BJ1SN

Orbiting moon since 25 May 14:08 UTC!

Downlink

  • Frequency
    • 435.400 / 436.400 MHz
  • Antenna
    • 2 × shortened monopole, 90° mounted
  • Polarization
    • Linear
  • Modulation
    • 250/500 bps GMSK with or without precoder
    • JT4G
  • Channel Coding (for GMSK)
    • 1/2 or 1/4 Turbo code
  • Randomizer (for GMSK)
    • CCSDS
  • Sync Word (for GMSK)
    • 0x034776C7272895B0 (1/2 Turbo)
    • 0x034776C7272895B0FCB88938D8D76A4F (1/4 Turbo)
  • Power
    • 33 dBm

Uplink

  • Frequency
    • VHF
  • Antenna
    • 2 × shortened monopole, 90° mounted
  • Polarization
    • Linear
  • Channel Coding
    • (7, 1/2) convolutional + (255, 223) RS
  • Modulation
    • 250 bps GMSK
    • DSSS-2FSK

Telemetry Decoder

Source Code and GRC flowchart based on GNU Radio

https://github.com/bg2bhc/gr-dslwp/

Tracking Files
https://github.com/bg2bhc/dslwp_dev/

VLBI

First test on 10 Jun 2018

Data from Beijing 12m dish
https://drive.google.com/file/d/1I4N9-1FYAYp8YRuI_WW49Hud1-vvDF4k
Data from Dwingeloo 25m dish
https://charon.camras.nl/public/dslwp-b/

Successful Configurations

Here is a collection of configurations of radio amateurs who have successful DSLWP downlink reports. Please contact bg2bhc#gmail.com for any update.

PY2SDR

  • Homemade 4-element LFA (yagi) antenna
  • Low noise preamp
  • RTL-SDR + LiveCD
  • Catched the first signals from DSLWP-A at 2018-05-20 22:15 UTC and DSLWP-B at 2018-05-20 22:20 UTC by waterfall.
  • Successful decoding until 2018-05-21 02:35 UTC, then UHF transmitter is turned off. Max range ~67500 km.

 

 

CD3NDC

  • Arrow antenna model Alaskan, 10 el
  • RTL-SDR + LiveCD
  • The second radio amateur to catch the UHF downlink of DSLWP.
  • 20 Jun: Found trace on waterfall but decoding is not successful.

PY4ZBZ

  • 10 el yagi 15 dBi, homemade preamp 0,5dB NF
  • The third radio amateur to catch the UHF downlink of DSLWP.
  • 20 May: Found trace on waterfall but decoding is not successful with RTL-SDR + LiveCD,
  • 16 Jun: Found trace on waterfall but no trial for decoding  with FunCubeDongle pro.

N6RFM

  • Custom “Alaskan” solid element Arrow antennas
  • SP-70 preamp
  • 28 meters 1/2 inch hardline
  • AirSpy SDR, gr-dslwp, Linux Mint 18.3
  • The fourth radio amateur to catch the UHF downlink of DSLWP.
  • Successful decoding until 2018-05-21 02:40 UTC, then UHF transmitter is turned off. Max range ~ 69500 km.

B1/BY2HIT

  • Old 12m C-band dish for INMARSAT TT&C in Shahe, Beijing. Modified by BY2HIT team for UHF and S-band reception.
  • VK3UM feed phased for circular polarization, then DCI-435-10C band pass filter, and SP-70 preamplifier.
  • USRP B210 SDR with onboard GPSDO for time and frequency reference.
  • First decoding on 23 May 12:20 UTC, ~321500 km.
  • 2 Jun 22:00 UTC, first decoding after lunar orbit insertion.

BA7KW

  • 4 × 23 el DK7ZB yagi, helical filter and preamplifier on rooftop.
  • USRP B210 SDR with onboard GPSDO for time and frequency reference.
  • Found trace on waterfall on 23 May but decoding is not successful.

SP5ULN

  • 19 el yagi, LNA and RTL-SDR.
  • Found trace on waterfall and partial successful decoding (too many error bits) on 3 Jun, 8 Jun and 11 Jun.
  • Successful JT4G decoding on 16 Jun.

PI9CAM

  • Dwingeloo telescope, 25m dish antenna.
  • USRP B210 & RTL-SDR.
  • First GMSK decoding on 3 Jun.
  • Successful JT4G reception on 16 Jun but no trial for decoding.

M0IEB

  • 436CP42UG & SP70 432MHz Masthead Preamplifier, on the roof, 6m boom away from the roof top.
  • USRP SDR.
  • Found trace on waterfall on 3 Jun but decoding is not successful.

PA3FXB

  • 28 el DK7ZB yagi, horizontal polarization.
  • SSB electronics preamp with a NF of around 0.8 dB.
  • Fun Cube Dongle & SDR Console V3.
  • Found trace on waterfall on 5 Jun but no trial to decode.

DK3WN

  • MASPRO 435HS20 2x20 el-X Yagi, 13.2 dBD RHCP
  • SP-7000 ssb-electronic 20db/0.9
  • 15 mtr H2000-Flex coax
  • 8 Jun: FT-736R + SDR-IQ (IF 13.68 MHz). Found trace on waterfall on but no trial to decode.
  • 10 Jun: FT-736R + SDR-IQ (IF 13.68 MHz), Airspy and RTL-SDR. Airspy IQ recordings successfully decoded with the help of EA4GPZ.
  • 11 Jun: 23/25 B1 beacons decoded with RTL-SDR.
  • 16 Jun: Successful JT4G and GMSK decoding
  • http://www.dk3wn.info/p/?cat=485

IW1DTU

  • 4x23 el yagi, horizontal polarization, theoric gain 23 dBi.
  • 0.5/30 dB LNA, 30m Aircom coax cable.
  • AOR-5000 receiver with GPSDO (Leo Bodnar) at 10 MHz and SDR-14 as panadapter.
  • 11 Jun: Found trace on waterfall but no trial to decode.
  • 16 Jun: Successful JT4G and GMSK decoding.

BG6LQV

  • Helix antenna, 10 turns
  • BU-435 preamplifier, FT857
  • 16 Jun: Successful JT4G decoding with WSJT-X 1.6.0

BD9BU

  • 2×13 el DK7ZB yagi
  • BU-435 preamplifier, FT-897D
  • 16 Jun: Found JT4G trace on waterfall but decoding not successful with WSJT 9.02
  • 19 Jun: Successful decoding with WSJT-X

G4RGK

  • 8 x 27el Yagis with Open Wire Feed system
  • 0.4dB NF MGF1302 Preamp
  • IC475 RX + WSJT9
  • Funcube + Map65
  • 16 Jun: Decoding not successful

4Z5CP

  • 4 × 16JXX70 antenna, homemade LNA ~0.3dB NF.
  • 16 Jun: Successful GMSK decoding with RTL-SDR, JT4G decoding not successful with TS-2000 and WSJT 9.

IU2EFA

  • Diamond A430S15, 15 el yagi 14.8 dBi, Yaesu G-5400B rotator
  • 13 mt of Hyperflex 10 cable, no preamplifications
  • Kenwood TS-790E Radio
  • 16 Jun: Successful JT4G decoding

JA0CAW

  • 14 el × 1(430M) Quad，homemade LNA (Mgf 1401 old FET), 5D2V(25M)
  • FT-847 + PC + WSJT 10
  • 16 Jun: Successful JT4G decoding

JA5BLZ

  • 16 Jun: Found JT4G trace on waterfall

BY2HIT

  • 8 × Diamond A430S10R yagi array
  • Helical filter, Mini-circuits ZRL-700+ LNA
  • USRP B210
  • 19 Jun: B0 JT4G not successful because of large frequency offset, but SNR should be enough. Successful B0 GMSK decoding after frequency offset fixed.

Wakayama University ifES Lab

  • 12m dish
  • DIY UHF Feed + LNA + BPF
  • USRP B210, onboard GPSDO
  • 19 Jun: Successful GMSK & JT4G decoding

SQ5KTM

  • 21 el V polarization F9FT yagi, RAS rotator
  • LNA MVV Wimo, IC-9100, PC, Win10
  • Successful JT4G decoding on 19 Jun