NPP High Rate Data (HRD) Broadcast

NPP High Rate Data (HRD) Broadcast 6 March 2008 John Staren NPP HRD

Outline • Requirements • Satellite • Ground • Implementation • Modes • Antenna • Spectrum • Current Test Status NPP HRD

Documentation • Data formats are contained in the NPP Mission Data Format Control Book (MDFCB) • Current revision is CH-01, 4/14/2006 • Available at GSFC DRL site, directreadout.gsfc.nasa.gov • Implementation is documented in the Spacecraft HRD RF ICD to Direct Broadcast Users • Current revision is CH-02, 10/10/2006 • Also Available at GSFC DRL site • Requirements are separate, in IRD • Current revision is CH-02, 12/13/2002 • Also Available at GSFC DRL site • Take a look inside the HRD RF ICD now… NPP HRD

HRD Requirements • CCSDS standards are used for packetization, framing, Reed-Solomon + ½ rate convolution coding, and selectable randomization (also used as a test pattern) • 15 Mbps, NRZ-M, QPSK, 7812 MHz, BER<1e-8 at 5 degrees when rain loss* = 3dB, 1 dB margin • Receive G/T ≥ 22.7 dB/K @ 5 deg, Implementation Loss ≤ 2.5 dB, Pointing loss ≤ 1 dB • C3S will provide NPP position, status, and scheduled outages of HRD & instruments. *Rain loss includes signal attenuation, effects of scintillation, and degradation of G/T due to rain. NPP HRD

HRD Transmitter Command I channel G1 and Data 15 Msps Differential 15 QPSK Convolu- tional Harm- onic Processor Mbps Encoder Modulator DATA SSPA FLTR LVDS ___ 15 Msps Mission Data (NRZ-L to NRZ-M) Q channel G2 Interface Filter (Science & TLM) CADU Encoder CLK X-Band Synth X-Band (RHCP) 7812 MHz NPP Spacecraft Direct Downlink User Ground Terminal I 15 Msps 15 Msps 15 Mbps Bit Differential Synch Decoder 15 Mbps QPSK Derandom- izer Viterbi Dnconverter (NRZ-M to NRZ-L) Demodulator Decoder 7812 MHz CCSDS 15 Msps Bit 15 Msps CADU Synch Q High Rate Bit Synchronizer Unit NPP HRD Configuration NPP HRD

NPP HRD Modes • Satellite HRD formatter allows a test mode to be enabled. • In test mode, the CCSDS randomization pattern is output. • Test Mode is for ground and contingency use only. NPP HRD

NPP Earth-Coverage Antenna • Earth-Coverage antenna is intended to be isoflux. • RED = required antenna gain to meet link margin (as a function of boresight angle, relates to ground elevation angle) • BLUE = measured antenna gain • GREEN (lower) = cross-polarization gain • Provides world-wide line-of-sight real-time data above 5 degrees. NPP HRD

NPP HRD Spectrum • NPP Spectrum was measured in RF compatibility testing. Center frequency = 7812.0 MHz. • No SRRC filtering is used. Filtering meets NTIA mask. NPP HRD

HRD Test Status • Spacecraft Integration • Transmitters passes comprehensive test, environments • Data sets recorded by BATC at opportune times • NPP RF Compatibility Test • Verified System Performance with C3S HRD Monitor in August 2005 • Sent recorded OMPS+ATMS data to DRL • NCT 2C • Will record HRD including VIIRS, CrIS, ATMS in mid-2008 • NCT3 • Mobile NISGS will process sensor data • All instruments will be integrated on satellite • Scheduled for 6/2009 NPP HRD

NPP HRD Antenna NPP HRD

Back-Up NPP HRD

NPP HRD Signal Characteristics NPP HRD

NPP HRD Formatting Figure 4-7 CCSDS Grade 2 HRD Formatting NPP HRD

HRD ICD Link Budget NPP HRD

NPP High Rate Data (HRD) Broadcast