Number range CHAPTER**DRAFT VERSION 2.0**

**of the**

**GOES Data Collection Platform Radio Set (DCPRS) CERTIFICATION
STANDARDS**

**at 300 bps and 1200 bps**

**NOAA / NESDIS**

![](media/image3.wmf){width="1.5in" height="1.5in"}

**Draft release date: May 26, 2006**

**TABLE OF CONTENTS**

***\*\*\*THE TABLE OF CONTENTS WILL BE REVISED WHEN THE CHANGES TO THE
CONTENT HAVE BEEN FINALIZED\*\*\****

**GOES DCS 300/1200 BPS DCPRS CERTIFICATION STANDARDS**

**FOR SELF-TIMED, RANDOM REPORTING, and INTERROGATE OPERATION**

**Introduction**

DCPRS Certification is achieved by demonstrating that a radio
transmitter fulfills each of the requirements set forth in this
document. NESDIS certification is \"type certification\", wherein a
representative production unit is tested and found to fulfill all stated
requirements. NESDIS certification of individual production units (those
having the same model number) is not required. **As a standard, this
document represents mandatory requirements---waivers will not be
accepted.**

To obtain "Type Acceptance" the manufacturer shall submit the DCPRS
schematics, data flow chart, electronics parts design data, unit and
system test data, and perform tests to demonstrate that each requirement
herein is met. This includes but is not limited to analysis of the
DCPRS' design and performance characteristics, performing unit tests at
room temperature, and over a range of temperatures and power supply
(battery voltage) variations.

Certification testing shall be run with standard laboratory test
equipment and with a NOAA supplied Test Receiver/Demodulator. This test
unit includes a computer output port from the demodulator for test data
extraction points from the unit under test. The output port is accessed
by the use of a "dumb" terminal which is obtained by running a terminal
emulation programs such as BitCom, COMMIT, etc. through an IBM desktop
or laptop PC. The test demodulator has other access points for "I" and
"Q" phase detector measurements. Test guidelines, procedures, etc. are
described in an appendix of this document. The NOAA Test
Receiver/Demodulator will be loaned for a period of up to sixty (60)
days to manufacturers after the required documentation and design data
requirements in Section 1 have been accepted and/or approved by the NOAA
NESDIS Certification Official.

Manufacturers are required to supply all other test equipment needed to
demonstrate compliance with the certification requirements. All test
equipment to be used must be identified in the manufacturer's initial
request for DCP certification and have verified calibrations to an
established test laboratory. A list of the recommended test equipment, a
typical test set up, and some of the capabilities of the NOAA provided
test set are included in Appendix A. Specific test channels for use by
manufacturers shall be assigned by NESDIS OSDPD as required.

**Document Organization**

The GOES DCPRS certification requirements are set forth in the following
four sections. The first section identifies the DCPRS certification
documentation required. The second section defines the DCPRS
certification reporting mode requirements. The third section focuses
upon the DCPRS transmit data format requirements which are not
considered to be temperature dependent. The fourth section involves
requirements for which performance may vary over temperature and power
supply variation such as output power, frequency stability, modulation
stability, carrier phase noise, transmit spectrum, etc.

**SECTION 1 - DCPRS Certification Documentation Requirements**

1.1 [Required Documentation]{.underline}

Manufacturers shall submit the following documentation at least 60 days
prior to beginning the formal DCPRS certification testing. While NESDIS
may review and comment on this documentation, all documentation is
considered 'PROPRIETARY' for government eyes only and not available to
any other party, unless so identified by the manufacturer.

a)  DCPRS Model Number with its respective data and/or specification
    sheet(s)

b)  DCPRS electrical and electronic circuit schematics.

c)  DCPRS software flow-charts that identify how the DCPRS reporting
    method(s) - random, self-timed, interrogated, message
    formatting/generation, frequency and time stability functions,
    Fail-safe operation, other functions are fulfilled.

d)  DCPRS antenna gain, polarization, axial ratio, and VSWR data. This
    data shall be used with the power amplifier output to determine the
    DCPRS EIRP.

e)  Manufacturers Proposed Test Procedures including test data sheets.

f)  DCPRS oscillator aging analysis data to demonstrate that the
    specified aging requirements are met.

g)  Preliminary DCPRS Transmit Spectrum (see paragraph 4.5)

1.2 [Emission Designators]{.underline}

The official emission designations for the DCPRS transmissions are
provided below and shall be used whenever an emission designator is
required.

a)  For 300 bps user data rate: 300HG1DEN.

b)  For 1200 bps user data rate: 1K20G1DEN.

c)  If any DCPRS is able to operate at 100 bps, in accordance with
    previous certification standards, the applicable emission designator
    is 400HG1DBN.

1.3 [Nameplate Information]{.underline}

Each DCPRS shall include a durable nameplate on its outer surface that
shall contain the following information as a minimum:

a)  Manufacturer's name, model number, and serial number

b)  Certification date for this model

c)  Defined input voltage range (see paragraph 4.0)

d)  Approved antennas for use with this DCPRS

e)  Emission designator(s) applicable to this model

**SECTION 2 - DCPRS Data Rate and Operating Mode Requirements**

For High Data Rate (HDR) operation a DCPRS may be designated for either
300 bps or for 1200 bps. Further the DCPRS manufacturer shall clearly
state the reporting mode(s) for the Model/unit (i.e. Self-timed, Random,
or Interrogate). A combination of two operating modes is permitted
providing this is so identified and that all applicable mode
requirements are met. The DCPRS certification official will identify
specific channels, GOES ID/DCP Address, and time slots as needed for any
'on-the-air' or 'GOES testing.'

2.1 [DCPRS Self-Timed reporting Mode Accuracy]{.underline}

> All DCPRS transmissions shall control the start time of their initial
> carrier-only period to be within less than or equal to ±0.25 seconds
> from the assigned reporting time (referenced to UTC) over the full
> range of operating conditions.

2.1.1 [Inhibiting Transmissions]{.underline}

> The DCPRS shall include a method to calculate the amount its internal
> clock differs from UTC over the full range of operating conditions.
> Should the DCPRS clock differ from UTC by more than ±0.25 seconds, the
> transmissions shall be inhibited.

2.1.2 [Proof of Performance]{.underline}

> During Certification tests the manufacturer shall show how the
> difference between the internal clock and UTC is calculated and shall
> show how the requirement of 2.1.1 will be met. The manufacturer shall
> demonstrate the basic factor(s) such as drift rate, used in the
> calculations.

2.2 [DCPRS Random Reporting Mode Requirements]{.underline}

> For random reporting certification manufacturers shall demonstrate
> that the DCPRS transmits at a maximum message length of 3 seconds for
> 300 bps and 1.5 seconds for 1200 bps. The same algorithm and/or
> processes used for 100 bps certification may be used. Definitions of
> pseudo binary and other concepts are included in Appendix B. Random
> reporting certification testing requires that manufacturer's
> demonstrate random message generation on an approved NESDIS channel
> and transmit DCP messages in the random mode for eight (8) or more
> hours with an average repeat interval of every 15 minutes. One of the
> data values to be transmitted in this testing shall be a message
> number counter.

2.3 [DCPRS Interrogate Reporting Mode Requirements]{.underline}

> [For DCPRS interrogate mode certification the unit shall be tested as
> a transmit/receive system. Thus not only all the DCPRS transmit but
> also the GOES Command Receiver requirements must be demonstrated. The
> DCPRS command receiver requirements are set forth in a separate
> document (TBD).]{.underline}
>
> [For 'on the air' testing a reply message must be generated when the
> interrogate command is received on the appropriate interrogate DCP
> GOES ID and a data transmission must be sent on the proper
> channel.]{.underline}

**SECTION 3 - DCPRS Data Format Requirements**

3.1 [DCPRS Message Format]{.underline}

The format of all messages shall meet the following requirements.

NOTES: ASCII EOT use for ASCII and Pseudo Binary Formats

International EOT used for Binary Format

Actual Message Length may not Exceed Fail-Safe Limits

> **Carrier**: 0.50 seconds for 300 BPS
>
> 0.25 seconds for 1200 BPS

**Clock**: 3 symbol periods, first 0 degrees, then 180 degrees, then 0
degrees.

> **Frame Synchronization Sequence (FSS):**
>
> The following 15 bit pattern shall be sent at the appropriate symbol
> rate with \"0\" representing 0 degrees and \"1\" representing 180
> degrees:
>
> (MSB) 000011001001010 (LSB) The left most bit is transmitted first.
>
> After the FSS is transmitted the GOES ID and all data shall be
> scrambled, and trellis encoded, as defined below.

**GOES ID/DCP address:**

31 bits plus an extra \"0\" inserted as the LSB to form 4 - 8 bits Bytes

> The GOES ID is a 31-bit Bose-Chaudhuri-Hocquenghem (BCH) encoded
> address with a zero included as the 32^nd^ LSB. This address shall be
> transmitted as the first 4 bytes of the data in the message in exactly
> the same manner as all the other data bytes in the message. For
> example, given the hex ID of **CE 12 00 B8**, the first byte
> transmitted is **CE** hex, followed by **12** Hex, followed by **00**
> hex, followed by **B8** hex or:
>
> **11001110 00010010 00000000 10111000**

**Flag Word: (LSB)** Bit 1 spare, undefined

> Bit 2 Clock updated since last transmission = 1, not = 0
>
> Bit 3 Data Compression on =1, off = 0 Possible Future Enhancement
>
> Bit 4 New Coding on = 1, off = 0 Possible Future Enhancement (Code
> format not yet defined)
>
> Bit 5 spare, undefined
>
> Bit 6 = 1 if ASCII or Pseudo Binary, otherwise = 0

Bit 7 = 1 if Pseudo Binary or Binary, otherwise = 0

> (MSB) Bit 8 Odd parity for ASCII formatted data
>
> Any DCPRS certified to this standard that will also be able to operate
> at 100 bps shall employ the short preamble defined in the 100 bps
> Certification Standard.

3.2 [Data Scrambling]{.underline}

> Starting with the first bit of the GOES ID, all DCPRS data shall be
> scrambled. The DCPRS serial data stream shall be "exclusive ORed"
> (XOR) with the serial binary string represented by the table below. It
> is shown as 40 bytes using hex symbols for convenience, and shall be
> used in a circular fashion throughout the message.

  ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
  53   12   72   B2   54   62   AA   E4   DB   A7   56   08   A8   09   B4   BF   61   DC   50   E3

  AB   7F   00   87   6D   F5   58   CC   CF   3E   E7   2A   7E   9B   5C   4D   CE   A5   3C   0A
  ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----

> Scrambling shall be performed on a byte-by-byte basis. For example,
> the first byte of the GOES ID example, CE (hex), would be XOR with the
> first byte in the table, 53 (hex), i.e., the serial string 1100 1110
> XOR with the serial string 0101 0011 to produce 1001 1101, or 9D
> (hex). Then the second byte of the GOES ID, 12 (hex), would be XOR
> with the second byte in the table, 12 (hex), to produce 00 (hex), and
> so on. After the last byte of the table 0A (hex), has been XOR with
> the 40th byte of the DCPRS message, the table would be cycled and the
> 41st message byte XOR with the first byte in the table, 53 (hex). This
> sequence would continue as many times as required for the duration of
> the message, including the EOT and flush bits.

3.3 [Trellis Encoding]{.underline}

Figure 3 provides a Functional Block Diagram of the Trellis encoder
required.

**Figure 3.3 Trellis Encoder Functional
Diagram**![](media/image4.wmf){width="6.125in" height="3.0in"}

> This logic generates sets of tri-bits, which are used to generate each
> 8- PSK symbol to be modulated.
>
> Each data byte contains 8 bits. These bits are split into four 2 bit
> pairs as shown in the table below. Each 2-bit pair is fed into the
> trellis encoder in order. Pair 1 is fed into the encoder, then pair 2,
> pair 3, and pair 4. Then pair 1 of the next byte, pair 2, etc.

  ----------------- ----------------- ----------------- -----------------
  MSB                                                   LSB

  Bits 7 & 6        Bits 5 & 4        Bits 3 & 2        Bits 1 & 0

  Bit Pair 4        Bit Pair 3        Bit Pair 2        Bit Pair 1
  ----------------- ----------------- ----------------- -----------------

> The trellis encoder takes a 2-bit pair and encodes it to a 3-bit
> symbol. This 3-bit symbol is then mapped to one of the eight phases
> for transmission as shown in Table 3.6. The initial state of the
> encoder shall be all zeros.

3.4 [Encoder Flush]{.underline}

> At the end of the message after transmitting the EOT, an additional 32
> zero (0) data bits shall be provided to flush the encoder and decoder.
> After the 32^nd^ flush bit is transmitted, the phase should be brought
> to zero and the carrier power shall be turned off. The turn-off time
> shall be one millisecond, maximum.

3.5 [DCPRS Modulation Encoding]{.underline}

> The transmitted data shall be phase mapped from the trellis encoder as
> follows:

+--------------+-------------+-------------+-------------------------+
| E-2          | E-1         | E-0         | Phase Symbol            |
|              |             |             |                         |
| MSB Bit      | Bit         | LSB Bit     | Degrees                 |
+--------------+-------------+-------------+-------------------------+
| 0            | 0           | 0           | 0                       |
+--------------+-------------+-------------+-------------------------+
| 0            | 0           | 1           | 45                      |
+--------------+-------------+-------------+-------------------------+
| 0            | 1           | 0           | 135                     |
+--------------+-------------+-------------+-------------------------+
| 0            | 1           | 1           | 90                      |
+--------------+-------------+-------------+-------------------------+
| 1            | 0           | 0           | 180                     |
+--------------+-------------+-------------+-------------------------+
| 1            | 0           | 1           | 225                     |
+--------------+-------------+-------------+-------------------------+
| 1            | 1           | 0           | 315                     |
+--------------+-------------+-------------+-------------------------+
| 1            | 1           | 1           | 270                     |
+--------------+-------------+-------------+-------------------------+

**Table 3.5 Phase Encoding**

3.6 [DCPRS Data Formats]{.underline}

> Three data formats shall be demonstrated ASCII, Pseudo Binary, and
> Binary. HDR pseudo binary shall be the same as for 100 bps DCPRS
> certification (see Appendix B).

3.6.1 [Prohibited Characters]{.underline}

> The requirement in previous versions of this document that
> transmission of certain specified control characters was prohibited,
> has been deleted. Requirements for Binary Mode will be set when a
> binary format is proposed and accepted. Manufacturers should be aware
> that the receivers are programmed to end reception of any message when
> an EOT character (defined below) is detected and may therefore wish to
> ensure an EOT is never transmitted in the body of a message.

3.6.2 [End Of Transmission (EOT)]{.underline}

> ASCII and Pseudo Binary Format Mode - An EOT character, bit pattern
> 00000100, transmitted with the LSB first, shall be sent immediately
> after the last symbol of sensor data. This bit pattern is an ASCII EOT
> with odd parity.
>
> Binary Mode - An (EOT) code word, 0110 0011 1100 1010 1101 1101 0000
> 0100 with the LSB transmitted first, shall be sent immediately after
> the last symbol of sensor data. This bit pattern is identical to that
> required for international DCPRS certification except an additional
> zero (0) is inserted as the MSB to provide an even number of bits to
> be sent to the encoder.

**SECTION 4 - DCPRS Performance Requirements**

> DCPRS performance requirements shall be demonstrated over a -40°C to
> 50C temperature range and over a power supply voltage range that is
> defined by the manufacturer. The DC power supply voltage shall be
> monitored both before and during a transmission and the RF
> transmission shall be inhibited if the defined range is exceeded.

4.1 [DCPRS Effective Isotropic Radiated Power (EIRP)]{.underline}

4.1.1 [RF Power Output]{.underline}

> For 300 bps, the DCPRS shall operate with an EIRP of 48 dBmi ±1 dB.
> For 1200 bps, the DCPRS shall operate with an EIRP of 51 dBmi ±1dB.
> These limits shall be met under any combination of operational
> conditions.
>
> NOTE: The satellite transponder has been designed to operate over the
> uplink EIRPs listed above. Levels higher that the maximum will tend to
> overload the transponder and are prohibited. Levels less than the
> minimum may not provide an acceptable error rate when a large number
> of channels are simultaneously active. The minimum is cited because it
> is the lower limit of the system design, but users are permitted to
> use lower EIRP at their own risk.

4.1.2 [DCPRS Antenna]{.underline}

4.1.2.1 [Antenna Polarization]{.underline}

> DCPRS antenna polarization shall be right-hand circular, according to
> IEEE Standard 65.34.159 and have an axial ratio not more than 6 dB on
> axis.

4.1.2.2 [DCPRS Antenna Gain]{.underline}

> The DCPRS antenna transmit gain shall be such that in combination with
> the DCP output power the maximum EIRP is not exceeded.

4.2 [GOES DCS Operating Frequency Requirements]{.underline}

4.2.1 [Operating Channels and Frequencies]{.underline}

> The DCPRS shall be able to operate at any of the designated channel
> center frequencies.
>
> For DCPRS operating at 300 bps:
>
> The DCPRS shall be able to tune to 532 channels at 750 Hz increments,
> from 401.701000 MHz to 402.099250 MHz. The channel 1 center frequency
> shall be 401.701000 MHz, channel 2 center frequency shall be
> 401.701750 MHz, channel 3 center frequency shall be 401.702500 MHz,
> etc., up to channel 532 at 402.099250 MHz.
>
> For DCPRS operating at 1200 bps:
>
> The DCPRS shall be able to tune the following sub-groups of channels
> in 2250 Hz increments. The first such channel shall be channel number
> 2, then channel number 5, channel number 8, etc., up to channel number
> 530, at 402.097750 MHz.
>
> The assigned DCPRS operating channel center frequencies for 300 bps
> and for 1200 bps operations are set forth in Appendix D. All
> frequencies listed in Appendix D shall be provided for 300 bps
> operation. Only those shown in bold shall be available for 1200 bps
> operation. However, actual operation at 1200 bps will be authorized
> only on a subset of these potential channels by the Office of the NOAA
> GOES DCS Program Manager.
>
> For certification testing, manufacturers shall demonstrate the
> synthesis of each of these over the entire range of the possible
> operation and at a minimum of five frequencies for 300 bps and five
> for 1200 bps selected at random by the NESDIS Certification Official.

4.2.2 [Frequency Stability, Long Term]{.underline}

> The DCPRS output frequency shall be maintained to within ±125 Hz of
> the channel center frequency due to any combination of operational
> conditions and for any channel.

4.2.3 [Short Term Frequency Stability]{.underline}

> The DCPRS output frequency shall maintain a short term stability of ±1
> Hz/s under any combination of power supply variation or temperature as
> set forth in paragraph 4.0. For certification testing the frequency
> shall be measured over 10 ten-second sample windows and the maximum
> difference over 100 seconds shall be recorded.

4.3 [DCPRS Modulation Output Symbol Rate]{.underline}

> For 300 bps certification the output symbol rate shall be 150 symbols
> per second ±0.025%.
>
> For 1200 bps certification the output symbol rate shall be 600 symbols
> per second ±0.025%.
>
> For certification testing the DCPRS is to be set to transmit 0.5
> second of carrier and then a continuous stream of "0-1" or 0 and 180
> clock transitions at the respective symbol rate. The symbol period is
> to be measured at the "I" output of the test demodulator.

4.4 [DCPRS Phase Modulation and Noise]{.underline}

> For certification testing phase modulation and noise measurements
> shall be referenced to the zero degrees modulation phase transmitted
> during the message preamble and perfect 45 degree increments around
> the 360 degree circle.

4.4.1 [Carrier Phase Noise]{.underline}

> The phase noise of the unmodulated carrier shall be equal to, or less
> than 2.0 degrees RMS, when integrated over the range 10 Hz to 150 Hz
> for 300 bps, and 36 Hz to 600 Hz for 1200 bps. This limit shall be met
> under any combination of operational conditions.

4.4.2 [Phase Modulation Bias]{.underline}

> The worst case offset or bias of any of the 8-ary modulation points
> shall be equal to, or less than 1.0 degrees, under any combination of
> operational conditions.

4.4.3 [Total Phase Error]{.underline}

> The RMS phase error due to all causes except phase modulation bias,
> and under any combination of operational conditions, shall be equal
> to, or less than 2.5 degrees. This shall include the contribution due
> to carrier phase noise per 4.4.1.

4.5 [DCPRS Transmit Spectrum]{.underline}

> The DCPRS shall be designed to be received by the CDA stations, which
> will include a RRC demodulator filter with an excess bandwidth factor,
> α, of 1.0, implemented as a fourth order FIR digital filter with 65
> taps, or more. (TBR)
>
> When modulated with a random data stream and measured on a spectrum
> analyzer using a 1 Hz resolution bandwidth, the peak response of the
> undesired part of the emission, relative to the peak response in the
> necessary bandwidth (NB), shall be equal to, or better than the
> following limits. (The NB is 300 Hz for 300 bps and 1200 Hz for 1200
> bps.)

a)  At any frequency removed from the channel center frequency by more
    than 75% of the NB, up to and including 150%, at least 25 dB
    attenuation.

b)  At any frequency removed from the channel center frequency by more
    than 150%, up to and including 300%, at least 35 dB attenuation.

c)  At any frequency removed from the channel center frequency by more
    than 300% of the NB, at least 43 + 10 log (P) dB attenuation, where
    P is the total mean power in watts in the necessary bandwidth.
    (NOTE: This includes harmonics and any spurious radiation.)

> For certification testing, manufacturers shall use spectrum analyzer
> with the RBW and VBW set to 1 Hz and averaging on, to provide a smooth
> trace so the performance at each frequency span can be clearly seen.
> The number of sweeps to be averaged may be limited to the number
> required to show visible improvement.
>
> Spectral masks are provided for reference in figures 4.5-1 and 4.5-2.

![](media/image5.wmf){width="6.548425196850394in"
height="3.441732283464567in"}

**Figure 4.5-1 Emission Mask for 300 bps Operation**

![](media/image6.wmf){width="6.548425196850394in"
height="3.4543307086614172in"}

**Figure 4.5-2 Emission Mask for 1200 bps Operation**

4.6 [Fail-safe Operating Requirements]{.underline}

> An independent or separate fail-safe circuit shall be provided to
> prevent a DCPRS from operating in an uncontrolled fashion. This
> independent circuit must "permanently" shut off the transmitter if
> either of the following two conditions is violated.

a)  Message is too long.

> For 1200 bps transmissions the maximum message length shall be 128,000
> bits
>
> For 300 bps transmissions the maximum message length shall be 32,000
> bits
>
> If any DCPRS includes operation at 100 bps, the maximum message length
> at that user data rate shall be 9600 bits
>
> These maximum message lengths are near 110 seconds, including the
> message format requirements. If a message contains more than these
> numbers of bits, the fail-safe may be tripped. If the total message
> length exceeds 110 seconds, the fail-safe shall be tripped.

b)  Message is sent too soon. There shall be a minimum of 30 seconds
    off-time between successive transmissions. If a second message is
    transmitted before 30 seconds has expired, then the fail-safe shall
    be tripped.

> The fail-safe capability must be demonstrated over the full range of
> operating conditions. Removal of DC power from the DCPRS shall not
> affect the operation of this function.
>
> **Notes:**

**1. The above term "permanently" requires a manual intervention or
reset of the DCPRS in order to restore the unit for operational use in
the DCS.**

**2. The Inhibiting Transmission requirements of subsections 2.1.1 and
4.0 are specifically NOT included in this subsection.**

**APPENDIX A - Recommended Test Equipment and Test Set Up**

The following test equipment or approved equal are recommended:

**[Spectrum Analyzer (SA)]{.underline}** - The SA is needed to perform
spectrum tests. The SA must be able to measure to the third harmonic at
1206 MHz and have the Resolution Bandwidth, averaging capability, etc.
necessary to demonstrate compliance with the required spectrum.

**[Frequency Meter (FM)]{.underline}** - The FM is needed to measure
transmit frequencies (401.7 to 402.1 MHz) and to measure the transmit
symbol rate. The FM shall be accurate to 0.001 PPM (parts per million).

**[Digital Multi-Meter (DMM)]{.underline}** - The DMM may be used for
power supply voltage, RMS response to measure phase noise, and other
measurements as deemed appropriate.

**[RF Power Meter (RFPM)]{.underline}** - The RFPM is used to measure
the RF power amplifier output power. The response needs to be to RMS
power. A Bird Wattmeter Model 43 with ±3 per cent accuracy at full range
or approved equal is acceptable for these measurements. The element
power rating shall be such that the power measurements shall be in the
top half of the range.

**[Signal Generator (SG)]{.underline}** - The SG is to be used for
mixing the 402 MHz signal to the 5 MHz IF of the test demodulator. The
SG phase noise shall be \< 0.1 degree RMS. An HP 8660C or approved equal
is acceptable for this testing.

**[Environmental Test Chamber (ETC)]{.underline}** - The ETC is used to
control the ambient test temperature of the DCP unit under test. A
--40C to 50C range or greater is required.

**[General Purpose Oscilloscope]{.underline}** - To measure or observe
the relationship of "I" and "Q" signals.

**[Laptop or IBM PC]{.underline}** - To interface with the NOAA provided
Demodulator Test Set.

**[Low Frequency Signal Controller/Modulator]{.underline}** - An HP
33120A or equivalent. Used to generate modulation patterns and IF
signals.

**[DCPRS Test Capabilities Required]{.underline}**

During certification testing manufacturers must be able to disable or
enable the DCP fail-safe circuitry as needed. Further a number of test
sequences must be available on the unit to test various DCP functions.
These include the following:

a\) Carrier only carrier phase noise, frequency

b\) Clock pattern "0-1\" spectrum and clock pattern check, symbol rate

c\) Repeating short message sequence format checks

d\) Longer message, repeating pattern modulation and Inter-symbol
Interference check, power measurement, spectrum

The typical test set up is shown in Figure A1.

The typical test set up is shown in Figure A1.

Some of the capabilities/features of the Test Demodulator are
highlighted below:

**[Unique Software Functions For the Test Set Demodulator]{.underline}**

**The demodulator makes signal quality measurements of all the signal
variables of power, frequency, and phase. In the test case the
measurements are required to be made in different sequences and
accuracy. In the test case the noise floor is the base line phase noise
of the system since the S/N typical of live signals is not applicable.**

**[Power Measurement]{.underline}**

**The total signal power out of the DCPRS shall be measured without
external filtering. Power measurements shall be made specifically for
unmodulated carrier, clock, and random 8 PSK modulation under standard
conditions. Accuracy shall be ±3% of full scale, or better. If the
measurements are equal, only 8 PSK modulated power need be measured at
other conditions.**

**[Frequency Measurement]{.underline}**

**Since the maximum frequency tolerance is only 125 Hz, it is necessary
to make each frequency measurement with an absolute accuracy of 1 Hz or
better. GPS or a reference traceable to NIST shall be used for
calibration.**

**[Phase Noise Measurement]{.underline}**

**A random set of symbols is sent by the test transmitter that has at
least 10,000 symbols. The phase is measured for each symbol and the
average and RMS jitter determined for each of the 45-degree nominal
modulation nodes.**

**[Symbol Rate]{.underline}**

**After carrier is sent clock symbols are sent continuously. There are
two points of measurement for symbol rate on the front panel of the
demodulator - the symbol strobe pulses and the \"I\" phase detector
output. Time between pulses should indicate 150 or 600 symbol per second
rate.**

**[Message Format]{.underline}**

**The test transmitter sends a defined message to the test receiver,
That same message should be repeated at the demodulator. ~~This message
will be sent for the three cases of the interleaver selections.~~**

**[Carrier Length]{.underline} - Time between the detection of power
level and first phase transition after phaselock.**

**[Clock and MLS bits]{.underline}**

**Phase \"1\" or \"0\" sent to the output port. The exact transmission
pattern is displayed.**

**[Scrambling and Trellis Encoding]{.underline}**

**If the correct encoding is followed the data sent to the output port
will be intelligible. An incorrect pattern will provide a meaningless
data string. A test mode is provided to print out the measured symbol
phase in terms of phase bin. The phase bins are numbered 0 to 71. This
is the raw data prior to any processing.**

**[EOT Detection]{.underline} - This should be visible in the test mode
and from the demodulator recognition mask.**

**Appendix B - GOES DCS Pseudo-Binary Data and Other Definitions**

[General]{.underline}

This standard specifies a standard format for Data Collection Platforms
(DCPs) transmitting on random reporting channels. The format has been
structured so as to also be compatible with many self-timed (in
particular) and interrogated DCPs. The standard is based heavily on two
assumptions: First, the proper interpretation and utilization of random
data requires a data processing element within the data flow. Second,
that the format of all transmissions from a complying platform can be
decodable through the use of a properly constructed data base which is
to be contained within the data processing facility.

This standard defines the necessary attributes of both a DCP and a data
base to make the data processable and useful. The manner in which a DCP
can be described by the data base determines both the format and the
operating characteristics of the DCP.

[DCPRS Message Format]{.underline}

The DCPRS transmission format is set forth in paragraph 3.1 for the
pre-amble (carrier, clock, and FSS), the GOES ID code, and Flag Word
(see Figure 1). The sensor or message data shall consist of a single
8-bit header word, followed by data from one or more sensors. As shown
in Figure 2, the header word is always a number between 0 and 63 and
represents the entry number in a DCP information file which describes
the format being used for that message. Thus, a DCP is capable of
transmitting up to 64 different formats and each format can be
determined fully by knowing the header word and accessing a data base
for that particular DCP.

+------+-----------+-----+----------+---+--------+---+---------+----+
| *    | **GOES ID | **  | *        | * | **M    | * | **      | *  |
| *PRE | 31-BIT    | FLA | *MESSAGE | * | ESSAGE | * | MESSAGE | *E |
| -AMB | ADDRESS** | G** | 1**      | S | 2**    | S | N**     | OT |
| LE** |           |     |          | P |        | P |         | ** |
|      |           | **  |          | * |        | * |         |    |
|      |           | WOR |          | * |        | * |         |    |
|      |           | D** |          |   |        |   |         |    |
+------+-----------+-----+----------+---+--------+---+---------+----+

**Figure 1. DCPRS Transmit Format**

  -------------------- ----------------- ----------------- ---------------
  **EIGHT BIT HEADER** **SENSOR 1 DATA** **SENSOR 2 DATA** **SENSOR N
  **WORD**                                                 DATA**

  -------------------- ----------------- ----------------- ---------------

**Figure 2. DCPRS Message or Sensor Data Format**

The sensor data after each header word must adhere to the following
requirements:

1\. [Pseudo Binary Data Format]{.underline}

> All header and sensor data will be converted to [pseudo
> binary]{.underline}, regardless of its format from the sensor (analog,
> BCD, grey-coders, events, etc.). All data will be transmitted in a
> \"modified ASCII\" format utilizing 6- bits of an 8-bit character to
> represent part of each binary number. For data requiring 12-bit
> precision, two consecutive modified ASCII characters are needed as
> shown in the example below:

  ---- ---- ------- ------- ------ ------ ------ ------ ---- ---- ------ ------ ------ ------ ------ ------
  P    1    2^11^   2^10^   2^9^   2^8^   2^7^   2^6^   P    1    2^5^   2^4^   2^3^   2^2^   2^1^   2^0^

  ---- ---- ------- ------- ------ ------ ------ ------ ---- ---- ------ ------ ------ ------ ------ ------

1st DATA CHARACTER 2nd DATA CHARACTER

**Figure 3. 12-Bit Precision Data**

> For 18-bit precision, three characters are required:

  --- --- ------- ------- ------- ------- ------- ------- --- --- ------- ------- ------ ------ ------ ------ --- --- ------ ------ ------ ------ ------ ------
  P   1   2^17^   2^16^   2^15^   2^14^   2^13^   2^12^   P   1   2^11^   2^10^   2^9^   2^8^   2^7^   2^6^   P   1   2^5^   2^4^   2^3^   2^2^   2^1^   2^0^

  --- --- ------- ------- ------- ------- ------- ------- --- --- ------- ------- ------ ------ ------ ------ --- --- ------ ------ ------ ------ ------ ------

1st DATA CHARACTER 2nd DATA CHARACTER 3rd DATA CHARACTER

**Figure 4. 18-Bit Precision Data**

> Note that bits 7 and 8 of each character are a \*\"one\" and an odd
> parity bit, respectively^\*^. Thus, data is always expressed by N
> characters, each character representing N x 6 bits of information.
> Data within a character is transmitted least significant bit first.
>
> ^\*^The 6-bit binary data sequence of all ones may be transmitted as
> 01111111 (an ASCII \"DEL\" character) or 10111111 (an ASCII "?"
> character).

2\. Signed Parameters

> Many parameters, temperatures in particular, may be expressed with
> negative values. In addition, the direction of change in a reading is
> often useful information and similar such parameter-related flags
> should also be handled efficiently. Therefore, data may be expressed
> in one of three ways:
>
> a\) as a positive fixed point value of precision (N x 6);
>
> b\) as a signed value in two\'s complement form having a precision of
> (plus or minus) (N x 6 -1); or
>
> c\) as a positive fixed point number of precision (N x 6 -1) with the
> high order bit used as a flag.
>
> As an example of a negative value, a temperature value of 17 degrees
> below zero could be expressed with six bits as 101111. Whereas, a
> signed value of \*+17 degrees would be expressed as 010001. See
> \"Definitions\" for an explanation of two\'s complement arithmetic.
>
> For parameters not having negative values, but designated as being a
> parameter with a f lag, the high order bit is the f lag and the
> remaining bits are data in binary form. The precise interpretation of
> the flag bit is to be defined in the DCP\'s associated data base. As
> an example, the 11 bit precision accumulated precipitation value of
> 000001111011 (123) could indicate both the value of 1.23 inches
> (accumulated) and the fact that it is raining at the time of the
> measurement. Conversely, a value of 100001111011 indicates the same
> reading but signifies that no perceptible change has occurred since
> the last sensor update.

3\. Order of Reporting

> The most current data will be reported first within the DCP message.

4\. Limitations on Data Content

This standard per se, places no restriction on the number of parameters
being sensed, the accuracy of the measurements, or the number of
readings within a message. The format of the message must, however, be
describable by a data base (located in the receive system\'s computer)
containing, at least, the following elements:

a\) For each parameter being reported;

> 1\) Precision of the measurement being reported. This will always be a
> multiple of 6 (6, 12, 18, 24, etc.) unless it is a signed parameter or
> has a high-order flag bit (than it is 5, 11, 17, 23, etc.).
>
> 2\) A flag indicating whether or not the data signed, or has a flag
> bit.
>
> 3\) Calibration coefficients which will be applied to the data (if
> necessary).

b\) For each possible format to be transmitted;

> 1\) The message format number (0-63) which corresponds to the 8-bit
> header word beginning each message.
>
> 2\) Parameter cycle time (in seconds or minutes) - an N/A (not
> appropriate) flag may be used to indicate data is not reported in
> cycles.
>
> 3\) Cycle offset (in minutes) \-- the time delay from the end of the
> last complete up-date cycle, reported, to the beginning of
> transmission. If this value is N/A, the data is assumed to be
> transmitted in real-time, or the time delay between measurement and
> reporting is to be reported as a parameter within the message. This
> value will be \*N/A for random or interrogated transmissions.
>
> 4\) A list of parameters contained within the message (or parameter
> cycle, if the data is reported in cycles): along with the time of the
> sensor update relative to the beginning of the message. If any given
> parameter is updated (reported) several times within a cycle, that
> parameter (with the corresponding time) will be listed for each
> update.
>
> If time delay is itself a reported parameter, it will be listed in the
> data base\--the \*DCP will transmit this value immediately before all
> parameters associated with it.
>
> 5\) Cycles per message (if appropriate). This value indicates the
> number of times the listed parameters are repeated. An N/A flag would
> indicate either no repeats, or an indeterminate number of parameter
> groups (a time delay value, with one or more data values).
>
> 6\) Multiple Messages Within A Transmission. A transmission may
> contain more than one message. Generally, multiple messages will be
> used when two or more formats (as defined in the data base) are needed
> to transmit all the desired data. Multiple massages can also be
> utilized to transmit new data along with previously transmitted data
> \-\-- where possible, multiple parameter cycles should be utilized in
> lieu of multiple messages.
>
> Transmissions containing multiple messages will have a single ASCII
> space character (00100000 - LSB first) between each message. Note: the
> seventh bit (underlined) is a zero and thus is not a valid data
> character.
>
> 7\) Bad Data. If a sensor fails, or if for some reason the DCP is
> unable to transmit, proper data, an ASCII (/) character (00101111) may
> be substituted for each data character. Note, the 7th bit of this
> character is not a one, and cannot therefore be a valid data
> character.

**Other DCPRS Definitions**

Transmission The combination of clear radio carrier and all bits of
identification, data and any special sequences sent by a DCP.

Message Relates to all or a portion of the data segment of a
transmission; the message is a segment of data that is fully defined in
a DCP management data base; a transmission will contain one or more
messages.

Header Word An 8-bit character whose low order 6 bits make up a binary
number that identified a format retry stored in a DCP management data
base for a specific DCP. A header word begins each message.

DCP Contains one record per DCP that includes Data Base the Management
characteristics of each parameter measured, plus a list of format
entries that will identify each potential data message that the DCP can
formulate and transmit.

Parameter Data element measured by a sensor. Common hydrometeorology
parameters include stream stage, precipitation, and temperature.

Parameter Entry of a value (composite or point) for into a parameter DCP
message. The

Update value may be an instantaneous value or a computed value based on
many sensor values measured since the last message update.

Cycle A procedure used by a DCP in acquiring and formatting multiple
readings obtained over a period of time. Generally a cycle consists of
specific measurements taken at prescribed times within a defined
interval. A DCP may acquire and report data for several such time
intervals by precisely repeating the prescribed cycle for each
consecutive interval.

Two\'s A method of expressing negative numbers so that subtraction may
be performed

Complement by a simple fixed-precision binary accumulator (adder). The
negative value of a binary number is computed by complementing each bit
and then adding one. (Example: The equation 4-6=-2 is computed as
4+(-6)=-2, which in 6-bit binary is 000100 + 111001 = 111101). The
magnitude of a negative value is determine by taking its
two\'s-complement. (i.e., -(-2)=+2 or -(11101)=000010).

**Appendix C - Interrogate DCP Receive Requirements**

C.1 [Received Frequency Characteristics]{.underline} - The DCP received
radio-frequency (RF) shall be as follows:

a.  The GOES East frequency - 468.8375 MHz

b.  The GOES West frequency - 468.8125 MHz

c.  Test/spare frequency - 468.8250 MHz

C.2. [Interrogate Signal Characteristics]{.underline}

a.  Modulation -- BPSK NRZ-L

b.  Data Rate (user) -- 1200 bps

c.  FEC Code -- Rate 1/2 convolutional inner code plus Reed-Solomon
    (255, 223) outer code. (Same as will be used for LRIT and EMWIN on
    GOES N/O/P.)

d.  RF Data Rate -- 2736 bps

e.  Data Filtering -- SRRC (for transmitters and receivers) with excess
    bandwidth factor () of 1.0 (Same as will be used for LRIT and EMWIN
    on GOES N/O/P.)

f.  Sideband Attenuation -- -30 dBc minimum

g.  Necessary Bandwidth -- 5472 Hz

h.  Satellite EIRP -- 40.0 dBmi

i.  Required bit error rate -- 10^-6^

j.  Worst Case DCPRS G/T -- -22 dB/K

k.  Worst Case DCPRS Demod/Decode Implementation Loss -- 2.0 dB

l.  Receiver tracking loop bandwidth -- 100 Hz (minimum)

**[Other Parameters:]{.underline}**

Any interested parties are requested to offer other parameters to be
included in the specification, or alternatives to those suggested above.
At the very least, a definition of the digital interface, the content to
be permitted, and the digital format, will need to be added to the above
partial description, or any alternative that may be proposed.

**APPENDIX D - GOES DCPRS TRANSMIT FREQUENCIES**

  ---------- ---------------- ---------- ---------------- ---------- ----------------
  CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY
  NUMBER                      NUMBER                      NUMBER     

  1          401.701000       46         401.734750       91         401.768500

  **2**      **401.701750**   **47**     **401.735500**   **92**     **401.769250**

  3          401.702500       48         401.736250       93         401.770000

  4          401.703250       49         401.737000       94         401.770750

  **5**      **401.704000**   **50**     **401.737750**   **95**     **401.771500**

  6          401.704750       51         401.738500       96         401.772250

  7          401.705500       52         401.739250       97         401.773000

  **8**      **401.706250**   **53**     **401.740000**   **98**     **401.773750**

  9          401.707000       54         401.740750       99         401.774500

  10         401.707750       55         401.741500       100        401.775250

  **11**     **401.708500**   **56**     **401.742250**   **101**    **401.776000**

  12         401.709250       57         401.743000       102        401.776750

  13         401.710000       58         401.743750       103        401.777500

  **14**     **401.710750**   **59**     **401.744500**   **104**    **401.778250**

  15         401.711500       60         401.745250       105        401.779000

  16         401.712250       61         401.746000       106        401.779750

  **17**     **401.713000**   **62**     **401.746750**   **107**    **401.780500**

  18         401.713750       63         401.747500       108        401.781250

  19         401.714500       64         401.748250       109        401.782000

  **20**     **401.715250**   **65**     **401.749000**   **110**    **401.782750**

  21         401.716000       66         401.749750       111        401.783500

  22         401.716750       67         401.750500       112        401.784250

  **23**     **401.717500**   **68**     **401.751250**   **113**    **401.785000**

  24         401.718250       69         401.752000       114        401.785750

  25         401.719000       70         401.752750       115        401.786500

  **26**     **401.719750**   **71**     **401.753500**   **116**    **401.787250**

  27         401.720500       72         401.754250       117        401.788000

  28         401.721250       73         401.755000       118        401.788750

  **29**     **401.722000**   **74**     **401.755750**   **119**    **401.789500**

  30         401.722750       75         401.756500       120        401.790250

  31         401.723500       76         401.757250       121        401.791000

  **32**     **401.724250**   **77**     **401.758000**   **122**    **401.791750**

  33         401.725000       78         401.758750       123        401.792500

  34         401.725750       79         401.759500       124        401.793250

  **35**     **401.726500**   **80**     **401.760250**   **125**    **401.794000**

  36         401.727250       81         401.761000       126        401.794750

  37         401.728000       82         401.761750       127        401.795500

  **38**     **401.728750**   **83**     **401.762500**   **128**    **401.796250**

  39         401.729500       84         401.763250       129        401.797000

  40         401.730250       85         401.764000       130        401.797750

  **41**     **401.731000**   **86**     **401.764750**   **131**    **401.798500**

  42         401.731750       87         401.765500       132        401.799250

  43         401.732500       88         401.766250       133        401.800000

  **44**     **401.733250**   **89**     **401.767000**   **134**    **401.800750**

  45         401.734000       90         401.767750       135        401.801500
  ---------- ---------------- ---------- ---------------- ---------- ----------------

**GOES DCPRS TRANSMIT FREQUENCIES (Continued)**

  ---------- ---------------- ---------- ---------------- ---------- ----------------
  CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY
  NUMBER                      NUMBER                      NUMBER     

  136        401.802250       181        401.836000       226        401.869750

  **137**    **401.803000**   **182**    **401.836750**   **227**    **401.870500**

  138        401.803750       183        401.837500       228        401.871250

  139        401.804500       184        401.838250       229        401.872000

  **140**    **401.805250**   **185**    **401.839000**   **230**    **401.872750**

  141        401.806000       186        401.839750       231        401.873500

  142        401.806750       187        401.840500       232        401.874250

  **143**    **401.807500**   **188**    **401.841250**   **233**    **401.875000**

  144        401.808250       189        401.842000       234        401.875750

  145        401.809000       190        401.842750       235        401.876500

  **146**    **401.809750**   **191**    **401.843500**   **236**    **401.877250**

  147        401.810500       192        401.844250       237        401.878000

  148        401.811250       193        401.845000       238        401.878750

  **149**    **401.812000**   **194**    **401.845750**   **239**    **401.879500**

  150        401.812750       195        401.846500       240        401.880250

  151        401.813500       196        401.847250       241        401.881000

  **152**    **401.814250**   **197**    **401.848000**   **242**    **401.881750**

  153        401.815000       198        401.848750       243        401.882500

  154        401.815750       199        401.849500       244        401.883250

  **155**    **401.816500**   **200**    **401.850250**   **245**    **401.884000**

  156        401.817250       201        401.851000       246        401.884750

  157        401.818000       202        401.851750       247        401.885500

  **158**    **401.818750**   **203**    **401.852500**   **248**    **401.886250**

  159        401.819500       204        401.853250       249        401.887000

  160        401.820250       205        401.854000       250        401.887750

  **161**    **401.821000**   **206**    **401.854750**   **251**    **401.888500**

  162        401.821750       207        401.855500       252        401.889250

  163        401.822500       208        401.856250       253        401.890000

  **164**    **401.823250**   **209**    **401.857000**   **254**    **401.890750**

  165        401.824000       210        401.857750       255        401.891500

  166        401.824750       211        401.858500       256        401.892250

  **167**    **401.825500**   **212**    **401.859250**   **257**    **401.893000**

  168        401.826250       213        401.860000       258        401.893750

  169        401.827000       214        401.860750       259        401.894500

  **170**    **401.827750**   **215**    **401.861500**   **260**    **401.895250**

  171        401.828500       216        401.862250       261        401.896000

  172        401.829250       217        401.863000       262        401.896750

  **173**    **401.830000**   **218**    **401.863750**   **263**    **401.897500**

  174        401.830750       219        401.864500       264        401.898250

  175        401.831500       220        401.865250       265        401.899000

  **176**    **401.832250**   **221**    **401.866000**   **266**    **401.899750**

  177        401.833000       222        401.866750       267        401.900500

  178        401.833750       223        401.867500       268        401.901250

  **179**    **401.834500**   **224**    **401.868250**   **269**    **401.902000**

  180        401.835250       225        401.869000       270        401.902750
  ---------- ---------------- ---------- ---------------- ---------- ----------------

**GOES DCPRS TRANSMIT FREQUENCIES (Continued)**

  ---------- ---------------- ---------- ---------------- ---------- ----------------
  CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY
  NUMBER                      NUMBER                      NUMBER     

  271        401.903500       316        401.937250       361        401.971000

  **272**    **401.904250**   **317**    **401.938000**   **362**    **401.971750**

  273        401.905000       318        401.938750       363        401.972500

  274        401.905750       319        401.939500       364        401.973250

  **275**    **401.906500**   **320**    **401.940250**   **365**    **401.974000**

  276        401.907250       321        401.941000       366        401.974750

  277        401.908000       322        401.941750       367        401.975500

  **278**    **401.908750**   **323**    **401.942500**   **368**    **401.976250**

  279        401.909500       324        401.943250       369        401.977000

  280        401.910250       325        401.944000       370        401.977750

  **281**    **401.911000**   **326**    **401.944750**   **371**    **401.978500**

  282        401.911750       327        401.945500       372        401.979250

  283        401.912500       328        401.946250       373        401.980000

  **284**    **401.913250**   **329**    **401.947000**   **374**    **401.980750**

  285        401.914000       330        401.947750       375        401.981500

  286        401.914750       331        401.948500       376        401.982250

  **287**    **401.915500**   **332**    **401.949250**   **377**    **401.983000**

  288        401.916250       333        401.950000       378        401.983750

  289        401.917000       334        401.950750       379        401.984500

  **290**    **401.917750**   **335**    **401.951500**   **380**    **401.985250**

  291        401.918500       336        401.952250       381        401.986000

  292        401.919250       337        401.953000       382        401.986750

  **293**    **401.920000**   **338**    **401.953750**   **383**    **401.987500**

  294        401.920750       339        401.954500       384        401.988250

  295        401.921500       340        401.955250       385        401.989000

  **296**    **401.922250**   **341**    **401.956000**   **386**    **401.989750**

  297        401.923000       342        401.956750       387        401.990500

  298        401.923750       343        401.957500       388        401.991250

  **299**    **401.924500**   **344**    **401.958250**   **389**    **401.992000**

  300        401.925250       345        401.959000       390        401.992750

  301        401.926000       346        401.959750       391        401.993500

  **302**    **401.926750**   **347**    **401.960500**   **392**    **401.994250**

  303        401.927500       348        401.961250       393        401.995000

  304        401.928250       349        401.962000       394        401.995750

  **305**    **401.929000**   **350**    **401.962750**   **395**    **401.996500**

  306        401.929750       351        401.963500       396        401.997250

  307        401.930500       352        401.964250       397        401.998000

  **308**    **401.931250**   **353**    **401.965000**   **398**    **401.998750**

  309        401.932000       354        401.965750       399        401.999500

  310        401.932750       355        401.966500       400        402.000250

  **311**    **401.933500**   **356**    **401.967250**   **401**    **402.001000**

  312        401.934250       357        401.968000       402        402.001750

  313        401.935000       358        401.968750       403        402.002500

  **314**    **401.935750**   **359**    **401.969500**   **404**    **402.003250**

  315        401.936500       360        401.970250       405        402.004000
  ---------- ---------------- ---------- ---------------- ---------- ----------------

**GOES DCPRS TRANSMIT FREQUENCIES (Continued)**

  ---------- ---------------- ---------- ---------------- ---------- ----------------
  CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY CHANNEL    CENTER FREQUENCY
  NUMBER                      NUMBER                      NUMBER     

  406        402.004750       451        402.038500       496        402.072250

  **407**    **402.005500**   **452**    **402.039250**   **497**    **402.073000**

  408        402.006250       453        402.040000       498        402.073750

  409        402.007000       454        402.040750       499        402.074500

  **410**    **402.007750**   **455**    **402.041500**   **500**    **402.075250**

  411        402.008500       456        402.042250       501        402.076000

  412        402.009250       457        402.043000       502        402.076750

  **413**    **402.010000**   **458**    **402.043750**   **503**    **402.077500**

  414        402.010750       459        402.044500       504        402.078250

  415        402.011500       460        402.045250       505        402.079000

  **416**    **402.012250**   **461**    **402.046000**   **506**    **402.079750**

  417        402.013000       462        402.046750       507        402.080500

  418        402.013750       463        402.047500       508        402.081250

  **419**    **402.014500**   **464**    **402.048250**   **509**    **402.082000**

  420        402.015250       465        402.049000       510        402.082750

  421        402.016000       466        402.049750       511        402.083500

  **422**    **402.016750**   **467**    **402.050500**   **512**    **402.084250**

  423        402.017500       468        402.051250       513        402.085000

  424        402.018250       469        402.052000       514        402.085750

  **425**    **402.019000**   **470**    **402.052750**   **515**    **402.086500**

  426        402.019750       471        402.053500       516        402.087250

  427        402.020500       472        402.054250       517        402.088000

  **428**    **402.021250**   **473**    **402.055000**   **518**    **402.088750**

  429        402.022000       474        402.055750       519        402.089500

  430        402.022750       475        402.056500       520        402.090250

  **431**    **402.023500**   **476**    **402.057250**   **521**    **402.091000**

  432        402.024250       477        402.058000       522        402.091750

  433        402.025000       478        402.058750       523        402.092500

  **434**    **402.025750**   **479**    **402.059500**   **524**    **402.093250**

  435        402.026500       480        402.060250       525        402.094000

  436        402.027250       481        402.061000       526        402.094750

  **437**    **402.028000**   **482**    **402.061750**   **527**    **402.095500**

  438        402.028750       483        402.062500       528        402.096250

  439        402.029500       484        402.063250       529        402.097000

  **440**    **402.030250**   **485**    **402.064000**   **530**    **402.097750**

  441        402.031000       486        402.064750       531        402.098500

  442        402.031750       487        402.065500       532        402.099250

  **443**    **402.032500**   **488**    **402.066250**              

  444        402.033250       489        402.067000                  

  445        402.034000       490        402.067750                  

  **446**    **402.034750**   **491**    **402.068500**              

  447        402.035500       492        402.069250                  

  448        402.036250       493        402.070000                  

  **449**    **402.037000**   **494**    **402.070750**              

  450        402.037750       495        402.071500                  
  ---------- ---------------- ---------- ---------------- ---------- ----------------

**Appendix E - GOES DCS Certification Test Notes**

**Link Phase Noise Budget**

A phase noise budget is proposed for the entire DCS so that each part of
the system can be individually tested, independent of the other parts,
and still be assured that all components that meet their assigned
requirement will provide acceptable system function.

The proposed budget for the DCPRS is derived as follows:

1.  The demodulators are expected to normally operate with a bit error
    rate near 1 in 10^7^, and it is desired that errors due to phase
    noise should be about two orders of magnitude better, i.e., about 1
    in 10^9^.

2.  Phase noise is a normal or Gaussian distributed variable, with
    standard deviation, . Therefore the dual-tail, Normal Error
    Integral gives a probability of 1 in 10^9^ that it exceeds 6.1 from
    its mean value.

3.  The total phase error required to cause bit errors in an 8PSK
    demodulator is 22.5 degrees, half of the 45 degree phase shift
    between each of the nominal phase states.

4.  This document proposes a DCPRS phase offset/bias 1.0 degrees.

5.  22.5 - 1.0 = 21.5 and 21.5 / 6.1 = 3.52

6.  Therefore, the total system phase noise must be 3.5 degrees or less.

7.  The phase noise in the GOES N primary and redundant DCPR
    transponders has been measured at 0.5 degrees, worst case. Therefore
    an allocation of 1.0 degrees is proposed for all of the GOES N and
    GOES R series of satellites.

8.  The DCPRS phase noise required by the current Certification
    Standards is 2.5 degrees.

9.  The phase noise allocation proposed for the dual down conversion
    receive path at WCDAS is 2.0 degrees.

10. The phase noise allocation proposed for the additional down
    conversion at the input to the demodulators at WCDAS is 1.0 degrees.

11. The RSS for all these components of the system phase noise is 3.5
    degrees.

The integration limits for calculating phase noise are 10 Hz and 150 Hz
for the 300 bps channels and 36 Hz and 600 Hz for the 1200 bps channels.
These are the values that will apply to the demodulators at WCDAS and
have been set as the standard to be used for the satellite and DCPRS
requirements. It is recommended that these values also be used in the
design of future demodulators for WCDAS and/or DRGS, at these data
rates.