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This specification replaces QJ 2322-1992 General specifications for satellite tracking and orbit satellite-borne system.
The following main changes have been made with respect to QJ 2322-1992:
a) The specification is renamed from “General specifications for satellite tracking and orbit satellite-borne system” to “General specification for spacecraft tracking, telemetry and command system” and the application scope is expanded from "satellites" to "spacecrafts", with relevant contents modified accordingly;
b) The frequency band selection is revised according to GJB 1198.4A-2004 Telemetry tracking command and data handling for spacecraft — Part 4: Ranging, and only UHF1 frequency band in the original standard is used;
c) SHF and VHF/UHF2 frequency bands are deleted;
d) The inspection rules are adapted and refined.
This specification was proposed by China Aerospace Science and Technology Corporation.
This specification is under the jurisdiction of China Academy of Aerospace Standardization and Product Assurance.
This specification was issued in March 1992 for the first time.
General specification for spacecraft tracking, telemetry and command system
1 Scope
This specification specifies the technical requirements, quality assurance requirements and delivery preparation for spacecraft tracking, telemetry and command system (herein after referred to as “TT&C system” and equipment (spatial part).
This specification is applicable to the design, manufacture, test and acceptance of spacecraft tracking, telemetry and command subsystem.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this specification. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this specification are encouraged to investigate the possibility of applying the most recent editions of the documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GJB 145 Specification of preservation packaging
GJB 152 Measurement of electromagnetic emission and susceptibility requirements for military equipment and subsystems
GJB 899 Reliability testing for qualification and production acceptance
GJB 1027-1990 Environmental test requirements for satellites
GJB 1198.4 Telemetry tracking command and data handling for spacecraft — Part 4: Ranging
GJB 1198.5 Telemetry tracking command and data handling for spacecraft — Part 5: Radio frequency and modulation
GJB 1216 General specification for contacts of electrical connectors
GJB 1217 Test methods for electrical connectors
GJB 1717 General specification for electrical connectors of general-purpose printed wiring boards
GJB 1909.4 Requirements of reliability and maintainability parameter selection and index determination for materiel — Satellite
GJB 2361 Methods for matching test of satellite and TT&C station
GJB 2998 Mark of satellite products
GJB 3590 Electromagnetic compatibility requirements for space systems
GJB/Z 35 Derating criteria for electrical, electronic and electromechanical parts
GJB/Z 55 Guideline for selection and application of spaceborne electric parts — Discrete semiconductor devices
GJB/Z 56 Guideline for selection and application of spaceborne electronic parts — Semiconductor integrated circuits
GJB/Z 83 Guideline for selection and application for spaceborne electronic parts — Microwave components and devices
GJB/Z 112 Guideline for selection and application of spaceborne electronic parts — Capacitor
QJ 165 General technical requirement for aerospace electronic and electrical product assembly
QJ 548 General technical requirements for part manufacture and mechanical assembling of electronics
QJ 908 Burn-in test of electronic products
QJ 1239.4 Environmental test conditions and methods for electronic equipment — Temperature variation test
QJ 1239.11 Environmental test conditions and methods for electronic equipment — Vibration test
QJ 1239.13 Environmental test conditions and methods for electronic equipment — Impact test
QJ 1239.14 Environmental test conditions and methods for electronic equipment — Acceleration test
QJ 1729A-1996 Test methods for aerospace antenna
QJ 1511 Acceptance specification for discrete semiconductor devices
QJ 1903 General specification for electrical connectors
QJ 1995 Acceptance specification for integrated circuits
QJ 2630.1 Space environment test method for satellite units — Thermal vacuum test
QJ 2630.3 Space environment test method for satellite units — Vacuum discharge test
QJ 2630.4 Space environment test method for satellite components — Magnetic test
QJ 2850 Prevention and control for foreign object debris (FOD) space products
QJ 3065.1 Management requirements for selection of components
QJ 3065.4 Management requirements for component screening and re-inspection
3 Requirements
3.1 General
The TT&C system and its equipment shall meet all requirements specified in this specification and corresponding detailed specifications. In case of any inconsistency between this specification and the detailed specifications, the latter shall prevail.
3.2 Main functions
The TT&C system shall have the following functions:
a) Complete the tracking and orbit determination tasks of spacecraft in the orbit injection and in-orbit operation phases;
b) Provide uplink and downlink radio frequency (RF) channels between spacecraft and telemetry, tracking and command station (hereinafter referred to as “TT&C station”);
c) Transmit director beacon signals and telemetry signals to the TT&C station;
d) Forward ranging signals and bidirectional coherent Doppler velocity measurement signals transmitted by TT&C stations;
e) Receive the uplink telecommand signal transmitted by the TT&C station and various data signals injected.
3.3 System composition
The basic configuration of the TT&C system is mainly composed of TT&C transponders (hereinafter referred to as “the transponders”) and TT&C antennas. According to the reliability requirements and TT&C requirements of each flight stage, the system is usually composed of two transponders, one TT&C antenna network and one set of TT&C antennas. Two receivers in the two transponders work at the same time in hot backup state, while only one set of transmitters works in cold backup, as shown in Figure 1.
Figure 1
3.4 Appearance
The coating, color and electrical connector arrangement on the outer surface of the product shall comply with the relevant interface data sheet, and the outer surface shall be free from damage, scratch and corrosion.
3.5 Markings
The product markings shall meet the requirements of GJB 2998. In addition to product code, number and stage marks, electrical connector marks shall also be provided.
3.6 Properties
3.6.1 Frequency band selection
The frequency band of the TT&C system shall be selected in accordance with GJB 1198.4 and GJB 1198.5. The operating frequency of the transponders shall be 2025MHz~2110MHz in the uplink and 2200MHz~2290MHz in the downlink.
3.6.2 Transponder
3.6.2.1 Main electrical properties of transponder
Main properties parameters of transponder shall meet the requirements of Table 1.
Table 1
No. Item Index
1 Uplink frequency a, MHz 2025~2110
2 Downlink frequency, MHz 2200~2290
3 Number of ranging sidetone a 7
4 Frequency ratio b 221/240
5 Frequency accuracy (during the life) Better than ±1.5×10-5
6 Short-term frequency stability (within 15min) Better than 1×10-7/s
7 Carrier spectrum purity, dBc Clutter suppression within 2.5MHz ≥-55
Clutter suppression within 500MHz ≥-40
8 Change range of input level of receiver, dB ≥60
9 Modulation mode a Uplink PCM/PSK/PM
Downlink PCM/DPSK/PM
10 Telecommand output Subcarrier frequency c, kHz 2~100
Bit rate d, kbit/s 0.1~8
Bit error rate e 1×10-6~1×10-7
Output level 500mVrms~1100mVrms
Output impedance ≤1kΩ
11 Telemetry input Subcarrier frequency f, kHz 5~512
Bit rate g, kbit/s 0.1~64
Bit error rate h 1×10-4~1×10-5
Input level 3.0Vp-p±5%
Input impedance ≥10kΩ
12 Ranging tone frequency Major ranging tone, kHz 100
Minor ranging tone 20kHz
4kHz
800Hz
160Hz
32Hz
8Hz
13 Ranging tone frequency on channel a, kHz Major ranging tone on channel 100
Minor ranging tone on channel 20.00
16.00
16.80
16.16
16.032
16.008
a Set the parameters in accordance with special technical specifications.
b It is the ratio of input frequency of uplink receiver to output frequency of downlink transmitter in coherent state.
c Existing models generally use 8kHz.
d Existing models generally use 2kbit/s.
e Existing models generally use 1×10-6.
f Existing models generally use 65.536kHz.
g Existing models generally use 4.096kbit/s.
h Existing models generally use 1×10-5.
3.6.2.2 Receiver threshold and transmitter power
The receiver threshold and transmitter power include the following requirements:
a) The tracking rate and capture threshold of the receiver shall meet the requirements of relevant detailed specifications, and the tracking rate shall be generally better than ±32kHz/s;
b) The lock-in threshold shall meet the requirements of the relevant detailed specifications.
c) The synchronous bandwidth and fast capture bandwidth shall meet the requirements of relevant detailed specifications, i.e., generally, the synchronous bandwidth shall be better than ±115kHz and the fast capture bandwidth shall be better than ±2kHz;
d) The center frequency deviation shall meet the requirements of relevant detailed specifications, and shall be generally better than ±35kHz/s;
e) The output power of transmitter shall meet the requirements of relevant detailed specifications;
f) Ranging error (including the correlation between uplink RF input level, Doppler frequency change and major ranging tone delay jitter) shall meet the requirements of relevant detailed specifications.
3.6.2.3 Ranging sidetone properties
Ranging sidetone properties shall meet the following requirements:
a) The selection of ranging tone frequency, channel ranging tone frequency and its number shall meet the requirements of Table 1;
b) The ranging sidetone signals shall be phase coherent.
3.6.2.4 Modulation properties
The modulation properties shall meet the following requirements:
a) The uplink signal modulation index shall meet the requirements of the ratio of signal power to noise power spectral density at the receiver input threshold of the transponder, and the downlink signal modulation index shall meet the requirements of the ratio of residual carrier signal power to noise power spectral density at the earth station and the requirements of power flux density limit. Each modulation index of the uplink and downlink signals by a single major ranging tone or a major ranging tone plus a primary ranging tone signal is 0.1~1.0rad, and the maximum square root of the sum of squares of modulation indexes does not exceed 1.4rad;
b) The phase delay between the channel ranging sidetone signal modulated on the uplink carrier frequency and the same channel ranging sidetone signal modulated on the downlink carrier frequency shall be a linear function of the ranging tone frequency.
c) The subcarrier frequency, bit rate, bit error rate and bit type of telecommand and telemetry shall meet the requirements of relevant detailed specifications.
3.6.2.5 Operating mode of transponder
Generally, the transponder shall have the following five operation modes:
a) single carrier;
b) only downlink telemetry;
c) uplink ranging + downlink ranging and telemetry;
d) uplink telecommand + downlink telemetry;
d) uplink ranging and telecommand + downlink ranging and telemetry.
3.6.2.6 Other requirements
The transponder shall forward the received uplink ranging tone signal without phase inversion.
3.6.3 TT&C antenna
The TT&C antenna shall meet the following requirements:
a) The frequency and bandwidth shall be matched with the transponder;
b) pattern: generally quasi-full space coverage;
c) phase change rate: generally, not more than 3 degrees/angle;
d) polarization: generally left-handed circular polarization;
e) The gain and power capacity shall meet the requirements of relevant detailed specifications;
f) receiving and transmitting isolation: better than 30dB;
g) impedance: 50Ω;
h) voltage standing wave ratio: not greater than 1.2 for at center frequency, and not greater than 1.5 for frequency band.
