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JHU/APL NCLT Interface Control Document TABLE OF CONTENTS 1
INTRODUCTION................................................................................................................................ 3 1.1 1.2 1.2.1 1.2.2 1.2.3 1.3 1.4
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NCLT MECHANICAL INTERFACE ............................................................................................... 6 2.1 2.2 2.3
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DIMENSIONS AND MOUNTING FOOTPRINTS................................................................................... 6 INTERFACE CONNECTORS AND CONNECTOR PIN-OUTS................................................................. 6 NCLT COMPONENT WEIGHT SUMMARY ..................................................................................... 6
NCLT ENVIRONMENTAL REQUIREMENTS ............................................................................. 7 3.1 3.2 3.3
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OVERVIEW ..................................................................................................................................... 3 DOCUMENT SCOPE ........................................................................................................................ 3 Interface Definition ............................................................................................................. 3 NCLT-to-Spacecraft Command and Data Product Definition............................................ 3 Cross-Link TDMA DataTransmission................................................................................. 3 NCLT COMPONENT INTERCONNECT BLOCK DIAGRAM ................................................................ 4 REFERENCE DOCUMENTS .............................................................................................................. 5
NCLT COMPONENT THERMAL INTERFACE ................................................................................... 7 NCLT COMPONENT POWER SUMMARY ........................................................................................ 7 NCLT COMPONENT LAUNCH VIBRATION REQUIREMENTS ........................................................... 8
NCLT MODULE STACK ELECTRICAL INTERFACE ............................................................. 10 4.1 NCLT COMPONENTS ELECTRICAL BOND TO STRUCTURE .......................................................... 10 4.2 GPS RECEIVER MODULE INTERFACE .......................................................................................... 10 4.2.1 NCLT Stack GPS RF Input................................................................................................ 10 4.2.2 TX 10 MHz Output ............................................................................................................ 10 4.2.3 RX 10 MHz Output ............................................................................................................ 10 4.2.4 EXT 10 MHz...................................................................................................................... 11 4.2.5 GPS Test Points................................................................................................................. 11 4.3 S-BAND RECEIVER MODULE INTERFACE .................................................................................... 11 4.3.1 S-Band RF Input................................................................................................................ 11 4.3.2 Spacecraft Power and T/R Interface ................................................................................ 11 4.3.2.1 4.3.2.2
4.3.3 4.3.3.1 4.3.3.2
Power ...................................................................................................................................... 11 T/R Control Interface.............................................................................................................. 13
Spacecraft Analog Telemetry Interface............................................................................ 14 Analog Telemetry Test Points ................................................................................................ 14 1PPS........................................................................................................................................ 14
4.3.4 RX Test Points Connector ................................................................................................. 15 4.3.5 RX 10 MHz ........................................................................................................................ 15 4.4 TRANSMITTER MODULE INTERFACE ............................................................................................ 15 4.4.1 S-Band Transmitter RF Output ......................................................................................... 15 4.4.1.1
TX Spectral Envelop .............................................................................................................. 17
4.4.2 TX 10 MHz ........................................................................................................................ 17 4.4.3 TX Test Point Connector................................................................................................... 17 4.5 PROCESSOR MODULE INTERFACE ................................................................................................ 18 4.5.1 Spacecraft Serial Communications Interface.................................................................... 18 4.5.1.1 4.5.1.2 4.5.1.3
4.5.2
Serial Port #1 .......................................................................................................................... 18 Serial Port #2 .......................................................................................................................... 18 Processor Reset....................................................................................................................... 19
CPU Test Port ................................................................................................................... 19
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GPS PREAMPLIFIER ELECTRICAL INTERFACE .................................................................. 19 5.1 GPS PREAMPLIFIER RF INPUT .................................................................................................... 19 5.2 GPS PREAMPLIFIER RF OUTPUT ................................................................................................. 20 5.3 EMI REQUIREMENTS APPLICABLE AT GPS PREAMPLIFIER INPUT .............................................. 21 5.3.1 Susceptibility of GPS Performance to EMI....................................................................... 21 5.3.2 GPS EMI Survival Levels.................................................................................................. 21
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S-BAND PREAMPLIFIER MODULE ELECTRICAL INTERFACE ........................................ 23 6.1 S-BAND PREAMPLIFIER ELECTRICAL INTERFACE ........................................................................ 23 6.1.1 S-Band Preamplifier RF Input .......................................................................................... 23 6.1.2 S-Band Preamplifier RF Output........................................................................................ 23 6.2 EMI REQUIREMENTS APPLICABLE AT S-BAND PREAMPLIFIER INPUT ........................................ 24 6.2.1 NCLT TX/RX Isolation ...................................................................................................... 24 6.2.2 Susceptibility of S-Band Performance to EMI .................................................................. 24 6.2.3 EMI S-Band Survival Levels ............................................................................................. 24
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T/R SWITCH ELECTRICAL INTERFACE.................................................................................. 26 7.1 T/R SWITCH INTERFACE .............................................................................................................. 26 7.1.1 Actuating Voltage and Current ......................................................................................... 26 7.1.2 T/R Switch State Control................................................................................................... 26 7.1.3 T/R Switch Telltale ............................................................................................................ 26 7.1.4 RF Ports ............................................................................................................................ 26 7.1.4.1 7.1.4.2 7.1.4.3 7.1.4.4
RF Antenna Port (Labeled IN on figure 1)............................................................................. 26 S-Band Input Port (Labeled #2 on figure 1) .......................................................................... 27 S-Band Output Port (Labeled #1 on figure 1) ........................................................................ 27 RF Port Specifications ............................................................................................................ 27
7.2 CIRCULATOR INTERFACE ............................................................................................................. 27 7.2.1 RF In Port ......................................................................................................................... 27 7.2.2 RF Out Port....................................................................................................................... 27 8
SYSTEM INTERFACE REQUIREMENTS ................................................................................... 27 8.1 8.2 8.3 8.4 8.5
SPACECRAFT ATTITUDE STABILITY............................................................................................. 27 GPS ANTENNA ELECTRICAL REQUIREMENTS ............................................................................ 28 S-BAND ANTENNA REQUIREMENTS ........................................................................................... 29 ANTENNA ISOLATION REQUIREMENTS ........................................................................................ 30 LINK BUDGET FOR MAXIMUM RANGE ........................................................................................ 30
Annex A – NCLT Mechanical Interface Annex B -- NCLT Interface Connectors and Connector Pin-Outs
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JHU/APL NCLT Interface Control Document 1
Introduction
1.1 Overview The NCLT is a low power GPS navigation and data communication system designed for spacecraft formation flying applications. Its function is to provide (a) absolute spacecraft position and velocity and UTC time, based on GPS navigation, and (b) data communications between spacecraft in the formation. Spacecraft-to-spacecraft communication links are located at S-Band and operate using time division multiple access (TDMA) techniques. 1.2
Document Scope
1.2.1 Interface Definition This Interface Control Document (ICD) specifies and controls the detailed electrical, mechanical, and thermal interface between NanoSat Cross-Link Transmission (NCLT) System components and the host Nanosat spacecraft. The current plan is to build three NCLT flight systems and install on three Nanosat spacecraft built by Utah State University, Virginia Technical University, and Washington State University respectively. The intent of this ICD is to provide sufficient information to install and integrate the NCLT on each respective NanoSat spacecraft. The three NCLTs are identical and the specifications given here in apply to all. Each set of NCLT hardware delivered by JHU/APL shall include (a) a NCLT module stack, (b) a GPS preamplifier module, (c) an S-Band preamplifier module, and (d) a transmit/receive (T/R) switch and associated circulator. This document provides interface specifications for all of the aforementioned NCLT hardware components. A complete NCLT system must include a GPS antenna and an S-Band antenna. These items are provided and installed by the NanoSat program. To meet NCLT operating requirements, these items must satisfy interface and performance guidelines as set forth in this document. 1.2.2 NCLT-to-Spacecraft Command and Data Product Definition The NCLT will communicate with the NanoSat spacecraft over a serial communications interface defined in this document. Specific data products exchanged and communication protocols will be given in a future annex to this ICD. 1.2.3 Cross-Link TDMA DataTransmission The standard operating mode for the 3 spacecraft NCLT configuration, to send and receive data over the cross-link, is time division multiple access (TDMA). The data sequence transmitted during each NCLT TDMA time slot will include data provided by the respective spacecraft. The final version of this ICD will provide an overview of NCLT TDMA operation and transmission message structure.
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JHU/APL NCLT Interface Control Document 1.3 NCLT Component Interconnect Block Diagram The following figure depicts (a) the interface between NCLT components and (b) the interface of NCLT components to the spacecraft. Although each set of NCLT components delivered by JHU/APL are identical, component location and cable routing on each spacecraft varies. NCLT component placement and cabling (consistent with interface definition and requirements given in this document) are the responsibility of the respective spacecraft integration teams. As shown in the following figure, interconnects between NCLT components generally consist of RF cable connections.
NCLT Module Stack
* --
GPS RF
EXT 10 MHz
J4
GPS Test Points
J2
GPS Antenna 1575.42 MHz
Indicates respective RF cable carries +5 v DC power to preamplifier on center conductor
*
Out
J3
GPS Preamplifier Module
In
GPS RCVR Module
J5 TX 10 MHz J6
RX 10 MHz
J5
J4
All interface cables are built and installed by nanosat program
Power & T/R Cntrl
+5 v, ±12 v, RTN
NanoSat Power System
T/R Control & Status
RX Test Points
NCLT S-Band RCVR Module J7
J3
TX Test Points
CPU Test Port
1575.42 MHz
+28 v Switch Power
J3 Analog Telemetry Receive S-Band *
Out
J2
J4
Transmit S-Band
S-Band Preamplifier Module
In
In
T/R Switch
Out
In
Circulator
NCLT S-Band Transmitter Module
2060 MHz S-Band CrossLink
1
2
MonoPole Omnidirectional S-Band Antenna
Termination 50 Ohm
J2
NCLT Processor Module
4
J2
4
NCLT Serial Communications --- Port 1 NCLT Serial Communications --- Port 2 Processor Reset
J3 From J4 S-Band Rcvr Module
1PPS
NanoSat Command and Telemetry System
Analog Telemetry Points 9
NCLT Component Interconnect and Spacecraft Interface
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JHU/APL NCLT Interface Control Document 1.4
Reference Documents
Doc Number
Source
Description
JHU/APL Document 7397-9100
JHU/APL
NCLT Product Assurance Implementation Plan
JHU/APL Document TBD
JHU/APL
NCLT Software ICD
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JHU/APL NCLT Interface Control Document 2
NCLT Mechanical Interface
2.1 Dimensions and Mounting Footprints Drawings of each NCLT component, indicating dimensions and mounting footprint, are given in Annex A of this document. 2.2 Interface Connectors and Connector Pin-Outs A listing of all NCLT component connectors and connector pin-outs are given in Annex B of this document. 2.3
NCLT Component Weight Summary
The following table lists the maximum weight budgeted for each NCLT component. The weight of NCLT interface cables, provided by the Nanosat program, and installed during spacecraft integration, are not included. NCLT Weight Summary NCLT Component
Weight Budget [kg]
NCLT Module Stack
0.75 kg
GPS Preamplifier
0.15 kg
S-Band Preamplifier
Pending
T/R Switch
Pending
RF Circulator
0.05 kg
Total NCLT Weight (Exclusive of Cables)
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NCLT Environmental Requirements
3.1
NCLT Component Thermal Interface
Operating Temperature The temperature at the mounting surface of all NCLT components shall be maintained by the spacecraft to the range of 0°C to +50°C. This temperature range shall be maintained with the NCLT powered either on or off; power dissipated by each NCLT when powered on is given below. The NCLT shall meet all operational interface and performance requirements over this range of temperatures. Survival Temperature All NCLT components shall survive without damage temperatures ranging from –10°C to +60°C at the respective NCLT mounting interface.
3.2 NCLT Component Power Summary The table below lists the maximum power dissipated by each NCLT component. Power drawn on each input power line is given in the electrical interface section of this document. NCLT Component Power Dissipation NCLT Component
Maximum Power [mw] Transmitting 250 mw
Transmitter Off
NCLT Module Stack
5400
4400
GPS
300
300
S-Band Preamplifier
300
300
T/R Switch
12
0
Circulator
12[1]
0
Radiated from Antenna
250 mw
0
6275
5000
Preamplifier
Total NCLT Power
Note [1] – power consumed goes to 0.25 watts if T/R switch is in the receive state and the transmitter is on
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JHU/APL NCLT Interface Control Document 3.3
NCLT Component Launch Vibration Requirements
All NCLT components shall survive without degradation in performance random vibration and sine vibration given as follows. Random Vibration The NCLT shall survive random vibration levels to 12.9 grms. This specification is applicable to all three axis. The spectral density of random vibration is given below. Spectral Density of Random Vibration Spectral Density 1.000 20
50
600
2000
PSD (g2/Hz)
12.9 grms
0.100
0.010 Frequency (Hz)
Spectral Density Vibration Parameters Frequency (Hz) 20 20-50 50 600 600-2000 2000
Power Spectral Density (g2/Hz) 0.025 +6 dB/oct 0.15 0.15 -4.5 dB/oct 0.025
Axes Overall Level Duration
X, Y, Z 12.9 grms 1 minute per axis
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JHU/APL NCLT Interface Control Document Sine Sweep The NCLT shall survive a sine sweep from 20 Hz to 500 Hz at a level of 0.5 g’s. This specification is applicable to all three axis. Sine Burst The NCLT shall survive spacecraft sine burst testing levels of 23.8 g in each of the primary axis of the spacecraft. The test frequency will not exceed 20 Hz. The figure below is an example of what the sine burst test will look like.
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JHU/APL NCLT Interface Control Document 4
NCLT Module Stack Electrical Interface
4.1 NCLT Components Electrical Bond to Structure It is anticipated the mounting interface of NCLT components will be in electrical contact with the spacecraft structure. It is recommended efforts be made to keep the DC electrical impedance -- between the NCLT component cases and spacecraft structure -- less than 2.5 millohms. 4.2
GPS Receiver Module Interface
4.2.1 NCLT Stack GPS RF Input Connector:
SSMA female
GPS RF Power Level
-105 dBm to –85 dBm typical GPS signal (30 dB preamp gain)
GPS RF Frequency
1575.42 MHz center frequency
Input RF Impedance
50 ohms nominal, VSWR < 1.5:1
Input Noise Figure
< 10 dB
Input Signal BW
2 MHz nominal
Input Signal Doppler
< ± 50 kHz in 350 km circular LEO
Grounding
Connector case electrically bonded to NCLT structure
DC Voltage
+5 volts DC on center conductor to provide power to GPS preamplifier
DC Load Current
< 60 ma
4.2.2 TX 10 MHz Output This is a 10 MHz reference signal output from the GPS receiver module to the S-Band transmitter module. Cabling is installed by JHUAPL and this is considered an interface internal to the NCLT.
4.2.3 RX 10 MHz Output This is a 10 MHz reference signal output from the GPS receiver module to the S-Band receiver module. Cabling is installed by JHUAPL and this is considered an interface internal to the NCLT. 10
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4.2.4 EXT 10 MHz This is a test point input to the GPS receiver module and is considered an interface internal to the NCLT. 4.2.5 GPS Test Points This interface provides test signal outputs for monitor of GPS receiver operation. This interface does not connect to the spacecraft and is considered an interface internal to the NCLT. 4.3
S-Band Receiver Module Interface
4.3.1 S-Band RF Input Connector:
SSMA female
S-band RF Power Level
-100 dBm to –40 dBm typical signal (30 dB preamp gain)
S-band Center Frequency
2060 MHz
Input RF Impedance
50 ohms nominal, VSWR < 1.5:1
Input Noise Figure
< 10 dB
Input Signal BW
2 MHz nominal
Input Signal Doppler
< ± 1 kHz
Grounding
Connector case electrically bonded to NCLT structure
DC Voltage
+5 volts DC on center conductor to provide power to Sband preamplifier
DC Load Current
< 60 ma
4.3.2 Spacecraft Power and T/R Interface 4.3.2.1 Power 4.3.2.1.1
NCLT Power Input Voltage Requirement
The NanoSat spacecraft shall provide all power input to the NCLT. Power shall be provided via a+5.0 volt line and ±12.0 volt lines. Approximately 6.275 watts is required 11
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JHU/APL NCLT Interface Control Document for a 100% functional NCLT operation. Detailed NCLT power requirements are given below. 4.3.2.1.2
Voltage Regulation
Static regulation of each voltage input to the GNS shall be regulated to within ±3% of its nominal value listed above. This requirement is applicable over the complete range of temperatures experienced by the NCLT (0°C to +50°C at NCLT mounting surface), for all load variations (NCLT loads or otherwise), and input line variations to the DC-DC converter. 4.3.2.1.3
Power Draw
Power loads (mw) on each voltage input line are listed below. These figures apply for a fully functional NCLT that is transmitting at full power. Operating loads may be less if the NCLT is placed in any lower transmit power levels. NCLT Power Draw Requirement NCLT Component NCLT Module Stack
Maximum Power [mw] Transmitter Radiating 250 mw
With 10 % Margin Added
+5 v
tbd
tbd
+12 v
tbd
tbd
-12 v
tbd
tbd
Total NCLT Power
6275 mw
T/R Switch +12 v
At switch transition, draws 500 ma pulse for 15 ms ; otherwise 0 ma drawn
Note -- NCLT module stack power draw includes power provided via module stack to GPS preamplifier and S-Band preamplifier 4.3.2.1.4
Voltage Spikes
Voltage spikes on any power input to the NCLT shall not exceed 150 mv peak-to-peak (pp). Spectral components shall be limited to a band from 10 kHz to 10 MHz. 4.3.2.1.5
Voltage Ripple
Voltage ripple on any input power line to the NCLT shall not exceed 100 mv pp. 4.3.2.1.6
Inrush Current
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JHU/APL NCLT Interface Control Document The NCLT shall not be required to provide current limiting on power input lines during power turn-on. 4.3.2.1.7
Reverse Voltage Protection
Not Required 4.3.2.1.8
DC Low Voltage Survival
The NCLT shall survive without permanent damage a low voltage condition -- defined as greater than 0 volts and less than 3% below nominal-- on any power input for an indefinite period. 4.3.2.1.9
Overvoltage Survival
The NCLT shall survive without permanent damage an overvoltage condition of 20% above nominal on any power input. These requirements apply to an overvoltage time duration of 15 ms or less. 4.3.2.2 T/R Control Interface 4.3.2.2.1
T/R Position Control
TX_ON_P(N) Definition This balanced set of digital signals -- output from the NCLT through the power connector -- shall control the state (transmit or receive) of the T/R switch. TX_ON_P(N) Signal Level Compatible with EIA standard RS-422A electrical interface. TX_ON_P(N) Polarity A high signal, i.e., TX_ON_P > TX_ON_N, selects the transmit position of the T/R switch, the reverse selects the receive position 4.3.2.2.2
T/R State Telltales
A set of telltale signals is received back from the T/R switch to indicate actual position of the switch. The telltales are comprised of 3 lines, namely Telltale POS 1, Telltale POS 2, and a common return. Telltale POS 1 shorted to the telltale common indicates the transmit state, Telltale POS 2 shorted to the telltale common indicates the receive state.
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JHU/APL NCLT Interface Control Document 4.3.3 Spacecraft Analog Telemetry Interface 4.3.3.1 Analog Telemetry Test Points A number of analog level test point signals shall be output from the NCLT to the spacecraft. These signals, consisting of NCLT temperature test points, receiver AGC test points , and voltage input test points, are intended for downlinking in spacecraft housekeep telemetry. These signals will not exceed 4 volts full scale and the output impedance is 10 k ohms. A specific listing and description of each telemetry test point is given in the connector pinout table given in Annex B. 4.3.3.2 1PPS In addition to the analog telemetry test points, this interface shall also carry a one pulse per second (1PPS) signal specified as follows. 1PPS Definition This signal is a 1 Hz square wave synchronized to UTC (USNO) 1PPS epoch times. This signal is actively steered by the GPS – when the GPS system is tracking GPS SVs and is navigating – to maintain alignment to within ±1 µs of UTC (USNO) 1PPS epoch times. GPS derived position, velocity, and UTC time tag data -- output over the serial communications bus in synchronism with the 1PPS – are valid on the respective 1PPS epoch. In the event the GPS drops out of the navigation state (due for example to GPS signal blockage), the 1PPS signals shall continue to be output. However, since time is no longer available from a navigation solution, the 1PPS will drift wrt to the UTC (USNO) epoch by no more than 1 µs per second. 1PPS Voltage Level CMOS +5 volt level 1PPS Polarity The 1PPS epoch is defined to occur on the positive going transition of the signal. 1PPS Epoch Time Step On entry to the GPS navigation state, the 1PPS epoch is delayed on a one-shot basis in order to synchronize to UTC (USNO) epochs. This process is referred to as a time step. The one-time delay between the two associated 1PPS epochs shall range from 1 to 2 seconds. (The spacing between 1PPS epochs is exactly one second at all other times). To alert the spacecraft that a time step is to occur, a time jump message shall be sent over the port #1 interface one second prior to the actual 1PPS time jump.
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JHU/APL NCLT Interface Control Document 4.3.4 RX Test Points Connector This interface is a test port and is considered internal to the NCLT. It does not connect to the spacecraft. Test signals and pin-outs are given in Annex B.
4.3.5 RX 10 MHz This is a reference 10 MHz input signal provided from the GPS receiver module. Cabling is installed by JHUAPL and this is considered an interface internal to the NCLT. 4.4
Transmitter Module Interface
4.4.1 S-Band Transmitter RF Output Connector:
SSMA female
TX Power Level
Range of 27 dBm to ≈ -33 dBm in 2 MHz bandpass about center frequency
TX Center Frequency
2060 MHz nominal
Center Frequency Stability
< ± 1 PPM (±2.060 kHz)
Carrier Phase Noise 1 Hz
< -65 dBc
100 Hz
< -125 dBc
10 kHz
< -145 dBc
TX RF Impedance
50 ohms nominal, VSWR < 1.5:1
Grounding
RF connector case electrically bonded to NCLT structure
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JHU/APL NCLT Interface Control Document Signal Structure Modulation Type
BI-Phase Shift Key (BPSK)
Modulation
PRN sequence modulated modulo-2 by message data
PRN Chip Rate
1.023 MHz
PRN Code Length
1023 chips
PRN Code Epoch Rate
1 kHz
Message Data Rate
500 bps (exactly 1/2 code rate)
Message Data Format
NRZL
PRN Code Assignments
GPS SV 33 through 37, selectable by command
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JHU/APL NCLT Interface Control Document 4.4.1.1 TX Spectral Envelop TX power spectral component outputs shall not exceed the RF spectral envelope levels indicated in the figure below. 24 dBm In ±1.023 Mhz Channel Bandwidth About fo
fo - 3 MHz
fo + 3 MHz +7 dBm
+7 dBm
-15 dBm
Note: Power level figures given refer to power in 1 Mhz Bandwidth
-15 dBm
-36 dBm
-36 dBm
-50 dBm
-50 dBm
1950 MHz
2025 MHz
fo fo -4 MHz
fo +4 MHz
2110 MHz
2210 MHz
fo = 2060 MHz
NCLT Transmitter RF Power Spectral Envelope
4.4.2 TX 10 MHz This is a reference 10 MHz input signal provided from the GPS receiver module. Cabling is installed by JHUAPL and this is considered an interface internal to the NCLT. 4.4.3 TX Test Point Connector This interface is a test port and is considered internal to the NCLT. It does not connect to the spacecraft. Test signals and pin-outs are given in Annex B.
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Processor Module Interface
4.5.1 Spacecraft Serial Communications Interface The NCLT serial ports connect to the spacecraft command and data handling (C&DH) system. Port #1 is used to send commands to the NCLT and transfer data from the NCLT. For the Utah State nanosat spacecraft only, Port #2 is used to transfer additional NCLT data to the spacecraft. A definition of all commands and telemetry data will be given in a future annex to the ICD. The electrical interface for serial ports #1 and #2 are specified below. 4.5.1.1 Serial Port #1 Protocol
RS-232C protocol compliant, Asynchronous Transmit and Receive
Electrical Level
Balanced EIA standard RS-422A voltage levels
Data Transfer
Full Duplex
Baud rate
38.4 kbaud
Interface Signals
Defined on pinout list, Annex B
Data Size
8 bit
Number of Start bits
one
Number of Stop bits
one
Parity
none
Flow Control
None
4.5.1.2 Serial Port #2 Protocol
RS-232C protocol compliant, Asynchronous Transmit and Receive
Electrical Level
Balanced EIA standard RS-422A voltage levels
Data Transfer
Transmit from NCLT to spacecraft only
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9.6 kbaud
Interface Signals
Defined on pinout list, Annex B
Data Size
8 bit
Number of Start bits
one
Number of Stop bits
one
Parity
none
Flow Control
none
4.5.1.3 Processor Reset Processor Reset Definition This signal is a pulse output from the spacecraft command and data handling (C&DH) system to the NCLT. A 1 ms time duration pulse will reset the NCLT processors and force the GPS and NCLT software to reboot. Processor Reset Level CMOS +5 volt level. A ‘low’ voltage level forces the processor to reset. Automatic Reset at Processor Power-Up At power-up of the NCLT, no external reset pulse is required to initiate processor boot-up and software load – at power-up this operation is performed automatically by the processor.
4.5.2 CPU Test Port This interface is a test port and is considered internal to the NCLT. It does not connect to the spacecraft. Test signals and pin-outs are given in Annex B 5
GPS Preamplifier Electrical Interface
5.1 GPS Preamplifier RF Input This interface connects to the GPS antenna Connector:
SMA Female
GPS RF Power Level
-135 dBm to –115 dBm typical GPS signal
GPS RF Frequency
1575.42 MHz center frequency
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JHU/APL NCLT Interface Control Document GPS Signal Bandwidth
2 MHz
Preamplifier BW (3 dB) (90 dB)
36 MHz ± 3 MHz 250 MHz ± 25 MHz
RF Impedance
50 ohms nominal, VSWR < 1.5:1, over signal bandwidth
Preamplifier Noise Figure
< 2.5 dB
Preamp 1 dB Compression
> 0 dBm
DC Input Impedance
< 1 ohm
Preamplifier Gain
30 dB nominal over signal bandwidth
Input Signal Doppler
< ± 50 kHz in 350 km circular LEO
Grounding
Preamplifier case electrically bonded to spacecraft frame
5.2 GPS Preamplifier RF Output This is the GPS preamplifier output and connects to the GPS RF input connector on the GPS receiver module installed in the NCLT stack. The GPS RF input electrical interface is described in prior sections of this document.
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EMI Requirements Applicable at GPS Preamplifier Input
5.3.1 Susceptibility of GPS Performance to EMI The maximum EMI Levels for GPS receiver operation without degradation in performance are given below. These EMI levels are applicable at the GPS preamplifier module input. In-Band CW
-120 dBm maximum in passband of 2.8 MHz about center frequency
In-Band Wide-Band (WB)
-120 dBm maximum measured in 1 MHz bandwidth, applicable in 2.8 MHz band about center frequency
Out-of-Band EMI
+10 dBm maximum total in stopband – see figure which follows
5.3.2 GPS EMI Survival Levels The maximum EMI levels the GPS preamplifier will survive without damage are given below In-Band CW
0 dBm maximum in 275 MHz band about center frequency
In-Band WB
0 dBm maximum total in 275 MHz band about center frequency
Out-of-Band EMI
+20 dBm maximum total in stopband – see figure which follows
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+10 dBm
+10 dBm <-- 275 MHz --> <- 2.8 MHz ->
0
10 GHz -120 dBm
1575.42 MHz
GPS Susceptibility to EMI -- Maximum EMI Power Levels
+10 dBm
+10 dBm <-- 275 MHz -->
0
10 GHz
39 MHz 0 dBm 1575.42 MHz
GPS Survivable EMI Power Levels
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6.1
S-Band Preamplifier Module Electrical Interface
S-Band Preamplifier Electrical Interface
6.1.1 S-Band Preamplifier RF Input This interface connects to the output (RF port #1) on the T/R switch. An S-Band RF input signal is received from the S-band antenna when the T/R switch is in the receive state. Connector:
SMA Female
Preamplifier Passband (1 dB)
2025 MHz to 2110 MHz
Preamplifier Gain
30 dB ±3 dB over passband
S-Band Receive Center Frequency
2060 MHz
S-Band Receive RF Power Level
-130 dBm to –70 dBm typical
Preamplifier Input Impedance
50 ohms nominal, VSWR < 1.5:1, over passband
Preamplifier Noise Figure
< 2.5 dB over passband
Preamp 1 dB Compression
> 10 dBm over passband
DC Input Impedance
< 1 ohm
Input Signal Doppler
< ± 1 kHz
Grounding
Preamplifier case is electrically bonded to spacecraft frame
6.1.2 S-Band Preamplifier RF Output This is the S-Band preamplifier output and connects to the S-Band RF input connector on the GPS receiver module installed in the NCLT stack. The S-Band RF input electrical interface is described in prior sections of this document.
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JHU/APL NCLT Interface Control Document 6.2
EMI Requirements Applicable At S-Band Preamplifier Input
6.2.1 NCLT TX/RX Isolation A minimum of 80 dB of isolation is required between the NCLT TX signal input to the T/R switch and the T/R switch input to the S-Band preamplifier when the T/R switch is in the transmit mode. This requirement is applicable in the band from 2025 to 2110 MHz. 6.2.2 Susceptibility of S-Band Performance to EMI The maximum EMI Levels for S-Band receiver operation without degradation in performance are given below. These EMI levels are applicable at the S-Band preamplifier module input. In-Band CW
-120 dBm maximum in band from 2025 MHz to 2110 MHz
In-Band Wide-Band (WB)
-120 dBm maximum measured in 1 MHz bandwidth, applicable in band from 2025 MHz to 2110 MHz. Total WB power in band from 2025 MHz to 2110 MHz shall not exceed –100 dBm
Out-of-Band EMI
+10 dBm maximum in stopband – see figure which follows
6.2.3 EMI S-Band Survival Levels The maximum EMI levels the S-Band preamplifier will survive without damage are given below In-Band CW
0 dBm maximum in band from 2025 MHz to 2110 MHz
In-Band WB
0 dBm maximum in band from 1925 MHz to 2210 MHz
Out-of-Band EMI
+20 dBm maximum in stopband – see figure which follows for transition band
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JHU/APL NCLT Interface Control Document
1925 MHz
2210 MHz
+10 dBm
+10 dBm
0 -120 dBm fo MHz 2025 MHz
2110 MHz
NCLT S-Band Receiver Susceptibility to EMI -- Maximum EMI Power Levels
1925 MHz
2210 MHz
+10 dBm
+10 dBm
0 0 dBm fo MHz 2025 MHz
2110 MHz
NCLT S-Band Receiver Survivable EMI Power Levels
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JHU/APL NCLT Interface Control Document 7
T/R Switch Electrical Interface
7.1 T/R Switch Interface The function of this switch is to connect the S-Band antenna either to the transmitter RF output or to the input of the S-Band preamplifier. 7.1.1 Actuating Voltage and Current A +12 volt actuation voltage shall be provided by the spacecraft power system. During each switch transition, from the transmit mode to the receive mode or vice-versa, the switch will draw 500 ma or less for a period of 15 ms or less. Otherwise, no power is drawn from the +12 volt line. Connector pinout is given in Annex B. 7.1.2 T/R Switch State Control The state of the T/R switch is controlled by TTL+5 volt level signals output from the NCLT module stack. Connector pinout is given in Annex B. These control signals are labeled POS1 and POS2 and control the T/R mode (state) as follows. Switching time, from one state to the other, takes 15 ms or less. POS1 POS2 T/R State 0v
+5 v
Transmit
+5v
0v
Receive
7.1.3 T/R Switch Telltale Telltales are returned from the T/R switch to the NCLT to confirm the state of the T/R switch. The telltales are in the form of contact closures indicating the actual T/R state as follows. Connector pinout is given in Annex B. Telltale POS 1 shorted wrt to common: Indicates Transmit State Telltale POS 2 shorted wrt to common: Indicates Receive State 7.1.4 RF Ports 7.1.4.1 RF Antenna Port (Labeled IN on figure 1) This RF port connects to the S-band antenna. When the T/R switch is in the transmit mode, the transmitter RF S-Band received at the S-Band input port connects to the antenna. When the T/R switch is in the receive mode, the RF S-Band received at the antenna connects to the S-Band output port.
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JHU/APL NCLT Interface Control Document 7.1.4.2 S-Band Input Port (Labeled #2 on figure 1) This RF port is cabled to the S-Band circulator output. The S-Band transmitter RF output interface is given in prior sections of this document. 7.1.4.3 S-Band Output Port (Labeled #1 on figure 1) This RF port is cabled to the S-Band preamplifier input. The S-Band preamplifier input interface is given in prior sections of this document. 7.1.4.4 RF Port Specifications RF Insertion Loss
< 0.2 dB from DC to 3 GHz
VSWR
< 1.2:1 from DC to 3 GHz
Impedance
50 ohms nominal
RF Isolation
> 80 dB
7.2 Circulator Interface The function of the circulator is to absorb S-Band transmitter output power in the event the S-Band transmitter is powered while the T/R switch is in the receive state. (As shown in figure 1, this device is inserted between the TX S-band output from the NCLT module stack and the T/R switch S-Band input). The insertion loss - from RF In to RF Out -is0.2 dB typical, 0.3 dB maximum at 2060 MHz 7.2.1 RF In Port This port connects to the S-Band RF output connector on the S-Band transmitter module located in the NCLT stack. This interface is specified in prior sections of this document. Connector type is given in Annex B.
7.2.2 RF Out Port This port connects to the S-Band input port on the T/R switch. The output is identical to the RF input, reduced by the insertion loss of 0.2 dB typical. Connector type is given in Annex B. 8
System Interface Requirements
8.1 Spacecraft Attitude Stability The NCLT will meet operational and performance requirements when the spacecraft is operating and configured as follows. ( a ) the spacecraft attitude is stable to within ±2° ( b) the spacecraft is nadir pointing
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JHU/APL NCLT Interface Control Document ( c ) the GPS antenna is mounted on the spacecraft top (zenith pointing) deck and meets field of view requirements given in following sections of this document (d) the S-Band antenna meets field of view requirements given in following sections of this document 8.2 GPS Antenna Electrical Requirements All requirements that follow apply to the GPS antenna following installation on the spacecraft. Center RX Operating Frequency
1575.42 MHz
Bandwidth
≥ ± 2.5 MHz about center frequency
Polarization
RHC Circular
Field of View (FOV)
surface that extends from an elevation of 0° to 90°. (The angle of elevation is defined as the angle between the local azimuth plane and the zenith direction)
Input Impedance
50 ohms nominal, VSWR < 1.5:1
RHC Gain
> –3 dBic over at least 90 % of surface extending from 10° to 90° elevation
LHC Suppression
> 7dB with respect to RHC in FOV
Sidelobe Gain
< –10 dBic over the surface extending from –10° to –90° elevation.
Antenna Axial Ratio
< 2:1, over the surface extending from +10° to +90° elevation and 2.5 MHz bandwidth
S-band Antenna to GPS Antenna Isolation
> 50 dB, applicable from 1573 MHz to 2110 MHz
Nanosat D.L. Antenna to GPS Antenna Isolation
> 50 dB, applicable from 1573 MHz to 2290 MHz
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JHU/APL NCLT Interface Control Document Operating Temperature Range Based on input from the NanoSat system engineer, it is anticipated the GPS antenna must operate and meet all aforementioned performance requirements over a temperature range of –40°C to +85°C. Survival Temperature Range Based on input from the NanoSat system engineer, it is anticipated the GPS antenna must survive -- without degradation in performance requirements -- a temperature range of –60°C to +100°C. 8.3 S-Band Antenna Requirements All requirements that follow apply to the S-band antenna following installation on the spacecraft. Operating Bandwidth
2025 to 2110 MHz
All specifications that follow are applicable over this frequency band. FOV (Field of View)
360° azimuth, ±10° elevation
Polarization
Vertical Polarization (VP) (at 0° elevation, the radiated E-field is parallel to the spacecraft nadir-zenith axis)
Gain
> -6 dBic within FOV
Input Impedance
50 ohms nominal, VSWR < 1.5:1
Transmit Power
30 dBm maximum
Cross-Polarization
< -15 dB relative to the VP signal, applicable over the FOV
Operating Temperature Range Based on input from the NanoSat system engineer, it is anticipated the NCLT S-Band antenna(s) must operate and meet all aforementioned performance requirements over a temperature range of –40°C to +85°C.
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JHU/APL NCLT Interface Control Document Survival Temperature Range Based on input from the NanoSat system engineer, it is anticipated the NCLT S-band antenna(s) must survive – without degradation in performance -- a temperature range of –60°C to +100°C. 8.4 Antenna Isolation Requirements To meet GPS and NCLT S-Band performance requirements, RF isolation is required between the S-Band antenna and the GPS antenna. In addition, isolation is required with respect to the NanoSat downlink antenna. Minimum isolation requirements, including the frequency bands over which these isolation requirements apply, are given in the table that follows. NCLT Antenna Isolation Requirements GPS Antenna
NCLT S-Band Antenna
Radiating Antenna
Radiating Frequency/ Power
Minimum Isolation Requirement
Applicable Frequency band
Minimum Isolation Requirement
Applicable Frequency band
NCLT S-Band
2025-2110 MHz/0.25 watts
50 dB
1573 to 2110 MHz
not applicable
not applicable
Nanosat Downlink Antenna
2200-2290 MHz/tbd watts
50 dB
1573 to 2290 MHz
50 dB
2025 to 2290 MHz
8.5
Link Budget For Maximum Range
The NCLT will meet all S-Band signal tracking and data recovery requirements at a minimum input carrier-to-noise spectral power density (C/No) of 42 dB-Hz (referenced to the S-Band preamplifier input). Maximum NCLT range occurs when the received SBand signal level results in this value of C/No. The table that follows is a link budget for a NCLT range of 50 km. Four items in this budget, namely minimum C/No, transmit power level, preamplifier noise figure, and T/R switch insertion loss, are NCLT system parameters that are the responsibility of JHU/APL. The remaining items are a function of NanoSat spacecraft design and –to meet a 50-km range requirement -- it is the responsibility of the NanoSat program to assure that portion of the budget is satisfied.
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JHU/APL NCLT Interface Control Document Item
Budget
Units
Requirement Responsibility
Required C/No
42
dB-Hz
JHU/APL
Minimum power spectral density ratio for 2 meter code jitter, 500 bps at BER =10E-7
Preamp NF
3
dB
JHU/APL
S-Band preamplifier noise figure (Maximum)
TX Power
24
dBm
JHU/APL
Max transmitter power output from CLT
RX Antenna Gain
-6
dBi
Nanosat
Minimum receive antenna gain in FOV
TX Antenna Gain
-6
dBi
Nanosat
Minimum transmit antenna gain in FOV
TX/RX switch insertion loss
-2
dB
JHU/APL
two way loss in T/R switch (Maximum)
Polarization Loss
-0.1
dB
Nanosat
Antenna polarization loss due to antenna misalignment and spacecraft pointing offset
RX Cable/connector losses
-0.5
dB
Nanosat
Losses in cables and connectors (4) from antenna toSBand preamp (Maximum)
TX Cable/connector losses
-0.5
dB
Nanosat
Losses in cables and connectors (4) from antenna to CLT transmitter output (Maximum)
dB
Nanosat
Propagation loss assuming 2100 MHz S-Band signal frequency
° kelvin
Nanosat
Maximum anticipated antenna temperature
Propagation Loss at -132.9 50 km Antenna Temperature
340.0
Computed Received -123.97 Power level @ 50 km
dBm
Computed System -171.1 Spectral Noise Power
dBmHz
Remarks
Received signal power as seen at the s-band preamp input
Computed C/No @ 50 km
47.18
dB-Hz
Signal-to-noise spectral density at preamplifier input
Margin C/No @ 50 km
5.18
dB-Hz
Margin -- may be interpreted as amount TX power level may be reduced (via command)
Max Range @ 90.740 C/No=42 dB-Hz
km
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Annex A to JHU/APL NCLT Interface Control Document – Draft #2 JHU/APL NCLT Mechanical Interface Annex A – TABLE OF CONTENTS 1.
NCLT MODULE STACK DIMENSIONS AND MOUNTING FOOTPRINT ......................... A-2 1.1 1.2 1.3
NCLT TOP VIEW DIMENSIONS (INCLUDES MOUNTING FEET).................................................. A-2 NCLT SIDE VIEW (INCLUDES CONNECTOR LOCATIONS) ......................................................... A-3 NCLT SURFACE........................................................................................................................ A-3
2.
GPS PREAMPLIFIER MODULE DIMENSIONS AND MOUNTING FOOTPRINT............ A-4
3.
S-BAND PREAMPLIFIER MODULE DIMENSIONS AND MOUNTING FOOTPRINT..... A-5
4.
T/R SWITCH MOUNTING FOOTPRINT AND DIMENSIONS .............................................. A-6
5.
RF CIRCULATOR MOUNTING FOOTPRINT AND DIMENSIONS..................................... A-6
A-1
Draft
Annex A to JHU/APL NCLT Interface Control Document – Draft #2 JHU/APL NCLT Mechanical Interface
1. NCLT Module Stack Dimensions and Mounting Footprint 1.1
NCLT Top View Dimensions (Includes Mounting Feet)
A-2
Draft
Annex A to JHU/APL NCLT Interface Control Document – Draft #2 JHU/APL NCLT Mechanical Interface
1.2
NCLT Side View (Includes Connector Locations)
1.3 NCLT Surface The NCLT mounting surface is flat aluminum. The exposed surface is black alodyned.
A-3
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Annex A to JHU/APL NCLT Interface Control Document – Draft #2 JHU/APL NCLT Mechanical Interface 2. GPS Preamplifier Module Dimensions and Mounting Footprint 4.50
4.25
0.125
4.00 0.25
0.25
0.50 IN
1.00
Mounting Surface
1.250 1.50
OUT
0.250 0.125 0.50
0.125 Units are in inches
A-4
Draft
Annex A to JHU/APL NCLT Interface Control Document – Draft #2 JHU/APL NCLT Mechanical Interface 3. S-Band Preamplifier Module Dimensions and Mounting Footprint Initial vendor estimates of dimensions are 1 x 3 x 8 inches exclusive of mounting feet S-Band preamplifier module mounting footprint and hole Pattern will be available after vendor receipt of purchase order.
A-5
Draft
Annex A to JHU/APL NCLT Interface Control Document – Draft #2 JHU/APL NCLT Mechanical Interface 4. T/R Switch Mounting Footprint and Dimensions The dimesions of the T/R switch are approximately 2.42 inches by 2 inches by 0.56 inches exclusive of connectors. Switch dimensions, mounting footprint, and hole pattern drawings will be available after vendor receipt of purchase order. 5. RF Circulator Mounting Footprint and Dimensions To be provided.
A-6
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs ANNEX B TABLE OF CONTENTS
1.
INTERFACE CONNECTORS........................................................................................................B-2
2.
NCLT MODULE STACK CONNECTOR PIN-OUTS ................................................................B-4
3.
2.1.
SPACECRAFT POWER INPUT & T/R INTERFACE ........................................................................B-4
2.2.
SPACECRAFT ANALOG TELEMETRY ...........................................................................................B-5
2.3.
SPACECRAFT SERIAL COMMUNICATIONS INTERFACE ................................................................B-6
2.4.
GPS TEST POINTS ......................................................................................................................B-7
2.5.
S-BAND RX TEST POINTS ..........................................................................................................B-8
2.6.
TX TEST CONNECTOR ...............................................................................................................B-9
2.7.
CPU TEST CONNECTOR ...........................................................................................................B-10
T/R SWITCH CONNECTOR PIN-OUT ....................................................................................B-11
B-1
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 1. Interface Connectors All NCLT component interface connectors including part numbers are listed in the tables below and on the next page NCLT Module Stack Interface Connectors Interface Description
Connector Designatio n
Connector Type or Part Number
Mating Connector
Pin-Out
Connector URL
GPS RF Input
J3
SSMA male
not applicable
GPS Test Points
J2
SSMA Female - M/A-COM P/N 1052-1300-00 15 Position Female Nanonics P/N STM015L2HN
15 Position Male Nanonics P/N STM015PC2DCxxx
RX 10 MHz
J6
SSMA Female - M/A-COM P/N 1052-1300-00
Cabled by JHU/APL to J6 on S-Band Receive Module
not applicable
TX 10 MHz
J5
SSMA Female - M/A-COM P/N 1052-1300-00
Cabled by JHU/APL to J2 on S-Band Transmitter Module
not applicable
EXT 10 MHz
J4
SSMA Female - M/A-COM P/N 1052-1300-00
Test Point Not Connected
not applicable
S-Band RF Input
J2
Spacecraft Analog Telemetry
J3
SSMA Female - M/A-COM SSMA male not applicable P/N 1052-1300-00 15 Position Female - Airborn 15 Position Male - Airborn NCLT ICD Annex 2 http://www.airborn.com/pdf P/N MM-222-015-275-32OS P/N MM-212-015-165-41Wx /mseries/m45-4853.pdf
S-Band RX Test Points
J7
15 Position Female Nanonics P/N STM015L2HN
Spacecraft Power Input & T/R Interface
J4
21 Position Male - Airborn 21 Position Female - Airborn NCLT ICD Annex 2 http://www.airborn.com/pdf P/N MM-212-021-175-32OS P/N MM-222-021-265-41Wx /mseries/m45-4853.pdf
RX 10 MHz (Input)
J5
SSMA Female - M/A-COM P/N 1052-1300-00
Cabled by JHU/APL to J6 on GPS Module
not applicable
SSMA Female - M/A-COM P/N 1052-1300-00 15 Position Female Nanonics P/N STM015L2HN
SSMA male
not applicable
15 Position Male Nanonics P/N STM015PC2DCxxx
SSMA Female - M/A-COM P/N 1052-1300-00
Cabled by JHU/APL to J5 on GPS Module
GPS Receiver Module
NCLT ICD Annex 2 http://www.nanonics.com/d wgs/n138-230.pdf
S-Band Receiver Module
15 Position Male Nanonics P/N STM015PC2DCxxx
NCLT ICD Annex 2 http://www.nanonics.com/d wgs/n138-230.pdf
S-Band Transmitter Module S-Band TX RF Output TX Test Connector
J4
TX 10 MHz
J3
J2
NCLT ICD Annex 2 http://www.nanonics.com/d wgs/n138-230.pdf not applicable
Processor Module Spacecraft Serial Communications Interface CPU Test Connector
J2
J3
25 Position Male - Airborn 25 Position Female - Airborn NCLT ICD Annex 2 http://www.airborn.com/pdf P/N MM-212-025-175P/N MM-222-025-265-41Wx /mseries/m45-4853.pdf 32OS 9 Position Female - Airborn 9 Position Male - Airborn NCLT ICD Annex 2 http://www.airborn.com/pdf P/N MM-222-0009-275-32OS P/N MM-212-009-165-41Wx /mseries/m45-4853.pdf
NCLT Interface Connectors -- Continued
B-2
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs GPS Preamplifier Module Interface Connectors Interface Description
GPS RF Input GPS RF Output
Connect Connector Type or Part or Number Designa tion
Mating Connector
Input
SMA Female
SMA male
Output
SMA Female
SMA male
S-Band Preamplifier Module Interface Connectors Interface Description
S-Band RF Input S-Band RF Output
Connect Connector Type or Part or Number Designa tion
Mating Connector
Input
SMA Female
SMA male
Output
SMA Female
SMA male
T/R Switch Components Connectors Interface Description
Connect Connector Type or Part or Number Designa tion
Mating Connector
T/R Switch S-Band RF to/from Antenna S-Band to Preamplifier S-Band from Transmitter Via Circulator Power and T/R Control Interface RF Circulator Input (from Transmitter) Output (to T/R Switch J2)
Input
SMA Female
SMA male
J1
SMA Female
SMA male
J2
SMA Female
SMA male
In
SMA Female
SMA male
Out
SMA Female
SMA male
---
B-3
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 2. NCLT Module Stack Connector Pin-Outs 2.1. Spacecraft Power Input & T/R Interface NCLT Power and T/R Switch Connector Designation: J4 on S-Band Rcvr Module Conector Type: 21 Position Male Airborn P/N MM-212-021-175-32OS Pin #
Signal ID
Voltage
Max Load (ma)
Power Signals 1
+5V
+5.0 ±0.15 volts
2
Return
Return
12
+5V
+5.0 ±0.15 volts
13
Return
Return
3
+12V
+12.0 ±0.36 volts
4
Return
Return
14
+12V
+12.0 ±0.36 volts
15
Return
Return
5 -12V 6 Return 16 -12V 17 Return T/R Switch Signals
-12.0 ±0.36 volts Return -12.0 ±0.36 volts Return Type
Description
7
TX_ON_P
Digital level output
High level turns S-Band T/R switch to the transmit state
18
TX_ON_N
Digital level output
Complement of the TX_ON_P signal
9
T/R_State1
Digital level Input
Low level indicates T/R switch in the RX state
8 10
RTN T/R_State2
Return Digital level Input
11 19 20 21
RTN RTN RTN RTN
Return Return Return Return
B-4
Low level indicates T/R switch in the TX state
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 2.2. Spacecraft Analog Telemetry Spacecraft Analog Telemetry Connector Designation: J3 on S-Band Rcvr Module Conector Type 15 Position Female - Airborn P/N MM-222-015-275-32OS Pin #
Signal ID
Type
1
Analog output Analog output
0 to 4 volts
10 k
3
GPS_AG C RX_TEM P 1_PPS
Output Impedance (Ohms) 0 to 4 volts 10 k
CMOS 5 volt
1k
4
TX_PWR
Digital 1Hz square-wave output Analog output
0 to 4 volts
10 k
5
RTN
Return
Ground
6
+5V_MO N
Analog output
0 to 4 volts
7
RTN
Return
Ground
2
Range
10 k
Scale Factor tbd
GPS receiver AGC voltage
tbd
S-Band receiver card temperature UTC one pulse per second epochs coincident on positive going edge Indicator of transmitted power level
tbd
+0.5 V/V +5 voltage input to S-Band receiver card (+5 V = +2.5 V Nominal)
8
+12V_M ON
Analog output
0 to 4 volts
10 k
+0.207 V/V
9
GPS_TE MP TR_STAT E1 TX_TEM P SBAND_A GC2 SBAND_A GC1 TR_STAT E2 12V_MO N
Analog output
0 to 4 volts
10 k
tbd
Digital Output
0 to 5 volts
10 k
Analog output
0 to 4 volts
10 k
tbd
Analog output
0 to 4 volts
10 k
tbd
Analog output
0 to 4 volts
10 k
tbd
Digital Output
0 to 5 volts
10 k
Analog output
0 to 4 volts
10 k
10 11 12
13
14 15
B-5
Description
-0.207 V/V
+12 voltage input to S-Band receiver card (+12 V = +2.5 V Nominal) GPS receiver card temperature Low level indicates T/R switch in the RX state S-Band transmitter card temperature S-Band receiver AGC voltage of RX #2 S-Band receiver AGC voltage of TX #1 Low level indicates T/R switch in the RX state -12 voltage input to S-Band receiver card (-12 V = +2.5 V Nominal)
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 2.3. Spacecraft Serial Communications Interface NCLT Spacecraft Serial Communications Connector Designation: J2 on Processor Module Conector Type 25 Position Male - Airborn P/N MM-212-025-175-32OS Pin #
1 14 7 20 4 17 10 23
Signal ID
Type
Level or Range
Description
RS-422 RS-422
Data bits transmitted from the CLT to spacecraft Complement of 'P' data
RS-422
Data bits received from the spacecraft
RX1 Digital data input Data -N TX2 Digital data output Data -P
RS-422
Complement of 'P' data
RS-422
Data bits transmitted from the CLT to spacecraft
TX2 Digital data output Data -N RX2 Digital data input Data -P RX2 Digital data input Data -N
RS-422
Complement of 'P' data
RS-422
Data bits received from the spacecraft
RS-422
Complement of 'P' data
TX1 Digital data output Data -P TX1 Digital data output Data -N RX1 Digital data input Data -P
2
RTN
return
ground
8
RTN
return
ground
5
RTN
return
ground
11
RTN
return
ground
25
RTN
return
24 12 13 3
CLT Digital reset pulse Reset-P input CLT Digital reset pulse Reset-N input CHASSI Chassis S NC No Connection
15
NC
16 6
ground RS-422 RS-422
Positive going pulse > tbd µs resets CLT & GPS software/hardware Complement of 'P' data
Chassis
Connection to chassis ground
-
No Connection
-
RTN
return
ground
NC
No Connection
-
18
NC
No Connection
-
19
RTN
return
ground
9
NC
No Connection
-
21
NC
No Connection
-
22
RTN
return
ground
B-6
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Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs
2.4. GPS Test Points GPS Test Points Connector Designation: J2 GPS Module Conector Type: 15 Position Female Nanonics P/N STM015L2HN Pin #
Signal ID
Type
Level or Output Range* Impedanc e (ohms)
Scale Factor
Description
Analog Signals 7
+5 V MonGPS
Analog output
0 to 4 volts
10 k
1.2 v/v
+5 voltage input to GPS receiver card
14
+12 V MonGPS -12 V MonGPS GPS_IF_OU T
Analog output Analog output Analog output
0 to 4 volts 0 to 4 volts -7 dBm
10 k
3 v/v
+12 voltage input to GPS receiver card
10 k
-3 v/v
-12 voltage input to GPS receiver card
1k
--
RTN
Ground
15 8 5
GPS downconverter IF Prior to A-D Converter
Digital Test Point Signals 1 3
GPS_TEST_ Digital level open/short EN* Input
10 k
Short to ground enables the GPS digital test point interface
Digital CMOS 5 pulse output volt
1k
Digital 1 µs pulse, 1 kHz rate, aligned with chan 1 C/A code epoch
Digital CMOS 5 pulse stream volt output GPS_C_CLO Digital CMOS 5 CK clock output volt
1k
Digital C/A code bits, 1.023 MHz chip rate, GPS chan 1
1k
Digital C/A code clock, 1.023 MHz, GPS chan 1 Digital baseband magnitude signal, 30 % duty cycle (average), high when analog BB exceeds 1 sigma average Digital baseband sign signal, 50 % duty cycle (average), high when analog BB exceeds 0 volts
RTN
9
GPS_EPOC H
4
GPS_CODE
10
Ground
12
GPS_MAG
Digital BB Data
CMOS 5 volt
1k
6
GPS_SIGN
Digital BB Data
CMOS 5 volt
1k
2
GPS_SA_CL Digital level CMOS 5 K output volt
1k
GPS Receiver Sample Clock, digital 5.714MHz
13
1_PPS_MON Digital level CMOS 5 output volt
1k
One pulse per second output
11
RTN
Ground
* -- Output voltage into open load
B-7
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 2.5. S-Band RX Test Points S-Band Rcvr Test Points Connector Designation: J7 on S-Band Receiver Module Conector Type: 15 Position Female Nanonics P/N STM015L2HN Pin #
Signal ID
Type
Level or Output Range* Impedance (ohms)
Description
Analog Signals 8
RX_IF1_OUT
9
RX_IF2_OUT
5
RTN
Analog output Analog output Ground
0 to 4 volts 0 to 4 volts
1k
open/ short
10 k
Short to ground enables the S-Band receiver digital test point interface
1k
S-Band Receiver 1 downconverter IF Prior to A-D Converter S-Band Receiver 2 downconverter IF Prior to A-D Converter
Digital Test Point Signals 1 3
RX_TEST_E N* RTN
Digital level Input Ground
4
SIGN1_MON Digital BB CMOS 5 Data volt
1k
Digital baseband sign signal, 50 % duty cycle (average), high when analog BB exceeds 0 volts
6
SIGN2_MON Digital BB CMOS 5 Data volt
1k
Digital baseband sign signal, 50 % duty cycle (average), high when analog BB exceeds 0 volts
7
DATA_POL
10 k
Short to ground invertes RX_DATA
10
SA_CLK_MO N
1k
Digital 5.714MHz Sample Clock, S-Band Receiver
1k
Digital baseband magnitude signal, 30 % duty cycle (average), high when analog BB exceeds 1 sigma average
12
Digital open/short level Input
CMOS 5 Digital volt clock output MAG1_MON Digital BB CMOS 5 Data volt
13
MAG2_MON Digital BB CMOS 5 Data volt
1k
Digital baseband magnitude signal, 30 % duty cycle (average), high when analog BB exceeds 1 sigma average
2
RX_STATUS
CMOS 5 volt
1k
S-Band Receiver On/Off Status
14
RX_DATA
CMOS 5 volt
1k
Demodulated data for BER testing
15
RX_CLK
CMOS 5 volt
1k
Data clock for BER testing
11
RTN
Digital level output Digital level output Digital level output Ground
* -- Output voltage into open load
B-8
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 2.6. TX Test Connector NCLT S-Band TX Test Points Connector Designation: J2 on Transmitter Module Conector Type: 15 Position Female Nanonics P/N STM015L2HN Pin #
Signal ID
Type
Level or Output Range* Impedanc e (ohms)
Description
Analog Signals 7
+5 V MonTX +12 V MonTX -12 V MonTX
Analog output Analog output Analog output
0 to 4 volts
10 k
+5 voltage input to S-Band Transmitter card
0 to 4 volts
10 k
+12 voltage input to S-Band Transmitter card
0 to 4 volts
10 k
-12 voltage input to S-Band Transmitter card
5
EXT_DATA
Digital level Input
CMOS 5 volt
1k
External data for Bit Error Rate (BER) testing
13
RTN
Ground
14 15
Digital Test Point Signals 1
TX_TEST_E Digital open/short N* level Input
10 k
Short to ground enables the TX digital test point interface
3
BER_TEST_ Digital open/short EN* level Input
10 k
Short to ground enables the Bit Error Rate (BER) test interface
9
TX_EPOCH
Digital pulse output
CMOS 5 volt
1k
TX 1 kHz code epoch, one chip duration
4
TX_CODE
CMOS 5 volt
1k
TX digital code bits
10
TX_C_CLO CK
Digital pulse stream output Digital clock output
CMOS 5 volt
1k
TX digital code clock, 1.023 MHz
12
TX_DATA
Digital BB Data
CMOS 5 volt
1k
TX data modulated onto CLT S-band output signal
6
TX_D_CLK Digital BB Data
CMOS 5 volt
1k
TX data clock, 500 hz square wave
2
TX_STATU Digital CMOS 5 S level output volt
1k
S-Band Transmitter On/Off Status
8
TEST_DAT A
1k
TX data monitor point
11
RTN
Digital Level Output Ground
CMOS 5 volt
* -- Output voltage into open load
B-9
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 2.7. CPU Test Connector CPU Test Connector Designation: J3 on Processor Module Conector Type: 9 Position Male - Airborn P/N MM-222-009-275-32OS Pin #
Signal ID
Type
Level or Range
1
TX Data 0
Digital data output
HCMOS
Data bits transmitted from the CLT
3
TX Data 1
Digital data output
HCMOS
Data bits transmitted from the CLT
2
RX Data 0
Digital data input
HCMOS
Data bits received by CLT
4
RX Data 1
Digital data input
HCMOS
Data bits received by CLT
6
RTN
return
ground
7
RTN
return
ground
8
RTN
return
ground
9
RTN
return
ground
5
Reset
Open Collector
B-10
Description
Short to ground to reset
Draft
Annex B -- JHU/APL NCLT Interface Control Document -- Draft #2 JHU/APL NCLT Interface Connectors and Connector Pin-Outs 3. T/R Switch Connector Pin-Out T/R Connector Located on T/R Switch Conector Type: 7 Position Male?? Switch Connector Pin #
Vendor ID
Type
Description
1
+12 VDC
Power Input
Switch Actuating Voltage
Spacecraft Power System
2
DC Return
Return
Actuating Voltage Return
Spacecraft Power System
3
POS 1
TTL +5 v Level
T/R State Contorl Input POS 1 = 0 v, POS 2 = +5 v à Transmit ?? mode
NCLT S-Band Receiver Module Connector J2 Pin # tbd
4
POS 2
5
Teltale POS 1
Contact open/close
6
Teltale Common
Return
7
Teltale POS 2
Contact open/close
TTL + 5 v level T/R State Control Input POS 1 = +5 v,POS 2 = 0 v à Receive ?? mode
Destination
NCLT S-Band Receiver Module Connector J2 Pin # tbd
Teltale – closure wrt common indicates transmit state
NCLT S-Band Receiver Module Connector J2 Pin # tbd
Teltale common return
NCLT S-Band Receiver Module Connector J2 Pin # tbd NCLT S-Band Receiver Module Connector J2 Pin # tbd
Teltale – closure wrt common indicates receive state
B-11
Destination Signal ID
Draft
