National Weather Service United States Department of Commerce

Severe Thunderstorms in the Ohio and Tennessee Valleys; Flash Flooding Possible in the Southwest

Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. Across the Southwest, monsoonal moisture will continue to bring heavy rain and a threat for isolated to scattered flash flooding through Saturday. Read More >

Sources for HRIT/EMWIN systems and components:

  • Some LRIT receiver manufacturers are offering HRIT/EMWIN receivers.
  • EMWIN system modifications may provides an alternative to replacing an entire system. Information on the fabrication of Intermediate Frequency (IF) and Radio Frequency (RF) digitizer boards, and use of software radios may be found online.

US Government auction of L-band frequency spectrum (1695 to 1710 MHz) adjacent to GOES-R HRIT/EMWIN transponder frequency is likely to adversely impact the reliability of HRIT/EMWIN signal reception in the US due to cell phone interference.

HRIT/EMWIN Downlink Characteristics (NESDIS-2)

Coding – BPSK

  • Convolutional rate ½ code with constraint length 7 concatenated with Reed Solomon (255,223) with Interleave = 4
  • Square Root Raised Cosine filtering using an Alpha factor of 0.3
  • The resulting “Necessary Bandwidth” for this signal will be 1.205 MHz

Modem Required: predicted C/No is in the range of 63-67 dB
Maximum Demodulator Required is -

  • Eb/No is 4.6 dB for a BER of 1x10-8 after decoding

Minimum Antenna System

  • At 5 degree elevation, the minimum antenna is 1.2 meter.
  • At 10 degrees or more elevation the minimum size is 1.0 meter
  • Using a LNA or LNB with a system noise temperature of about 200 K will provide a G/T of 1.0 dB/K or -0.3 dB/K respectively