Technical Summary

The antenna system automatically tracks satellites and receives direct broadcast RF transmissions which are focused into the scalar feed horn by the parabolic dish and then fed to the low-noise block downconverter. This amplifies the signal and downconverts it to a lower frequency to minimise cable loss.

The signal is then fed to the RF module in the system interface rack, where it is downconverted to a common frequency (720MHz) and fed to the demodulator.

The demodulator converts the RF signal back to a binary data stream which is then Viterbi decoded, byte-aligned and streamed via a TCP socket to the Polar Orbiter Ingester software running on the ingest PC. This detects the attached synchronisation markers (ASMs) in the data stream and extracts the CCSDS frames (VCDUs) which are then derandomised and Reed-Solomon decoded.

In the case of Terra, Aqua, Suomi NPP and JPSS, the decoded VCDUs are automatically streamed via a TCP socket to the RT-STPS software running on the processing and visualisation PC, which processes them and displays a preview in the Simulcast software. The IPOPP software automatically processes the resulting data sets into level 0, 1 and 2 data and products.

FengYun-3 data is assembled into a file which is automatically transferred via a LAN connection to the FY3L0pp and FY3L1pp software running on the processing and visualisation PC. This automatically produces level 0 and 1 data and products.

Land-based and marine antenna specifications
Radome 2m diameter, low-loss composite, hydrophobic coating, white or grey
Antenna type Prime focus parabolic dish, solid spun aluminium, white powder coated
Diameter 1.5m
F/D ratio 0.364
Gain @ 8200MHz 39.3dBiC including 0.4dB radome loss
Feed Scalar horn
Frequency range 7200–8500MHz
Axial ratio 2dB max
Polarisation RHC/LHC, software controlled
Wind speed 185km/h (100kt) operational
240km/h (130kt) survival
Demodulator specifications
Input frequency X-Band 720MHz, L-Band 140MHz
Input dynamic range –60dBm to 0dBm nominal
Implementation loss <0.2dB typical @ 1:106 BER
Symbol rates 0.1–100Msps
Baseband filter Root raised cosine (RRC) with variable alpha
Convolution decoding Viterbi, K=7, rates ½ and ¾, single and dual channel, G1=171, G2=133
Monitoring/control RJ45 Gigabit Ethernet
Web interface, OSCP interface
Data outputs RJ45 Gigabit Ethernet
Up to 5 simultaneous TCP streams
SMA clock and data
Supported services Terra, Aqua, Suomi NPP,
JPSS-1/2/3/4, FY-3D/E/F,
Typical system G/T 19.4dB/K @ 8200MHz
Low-noise block downconverter (LNB) specifications
Input frequency 7750–8400MHz
Noise figure 0.69dB (50K) maximum
0.6dB (43K) typical
LO frequency 6950MHz
IF output frequency 800–1450MHz
Gain variation within 30MHz ±0.4dB maximum
Gain variation over band ±2dB max
Conversion gain 55dB minimum
Image rejection 40dB minimum
Local oscillator stability ±1.5ppm (–40 to +80°C)
Local oscillator type Internal Phase Locked Loop (PLL) locked to Temperature Controlled Crystal Oscillator (TCXO)
Phase noise –90dBc/Hz @ 10kHz typical
–100dBc/Hz @ 100kHz typical
System interface rack RF module specifications
Input frequency 800–1450MHz
Noise figure 4dB maximum
LO frequency 1520–2170MHz programmable in 100kHz steps
LO stability ±5ppm
Oscillator phase noise –100dBc/Hz @ 10kHz typical
Output frequency 720MHz
Converted bandwidth 160MHz @ 3dB
IF filter Dielectric
IF filter bandwidth 140MHz @ 1dB
160MHz @ 3dB
Conversion gain 20dB typical
Output 1dB compression point >+19dBm
Monitoring/control 2 × RS-232 serial via USB,
software controlled

Combined X/L-Band Option