Operational Description

FCC ID: P8CTT-951

Operational Description

Download: PDF
FCCID_303522

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - 3 GENERAL INFORMATION 3.1 TYPE DESIGNATION 2 The equipment has been designated by ACSS as models TT-95x T CAS Computer Units, P/Ns 9000000-20001 (TT-952), 9000000-55001 (TT-951), 9000000-1001 (TT-950). 3.2 SERVICE AND RULE FOR INTENDED OPERATION Air Traffic Control Part 87, Subpart A 3.3 DESCRIPTION OF EQUIPMENT 3.3.1 TAWS/Windshear Functionality The TAWS/Windshear function is implemented as an independent processor and I/O circuitry from the TCAS function. The TAWS/Windshear circuitry is contained on a unique circuit card assembly (CCA), which is added to the existing TCAS-2000 unit design in a spare card slot The TAWS function uses vertical speed, ground speed, track angle, flight path angle, latitude, longitude, flap status, steep approach status, static air temperature, roll angle, pressure altitude system inputs. A database, which includes terrain data, airport data, aircraft performance data and climb rate models, is used for the determination of the alerts and display of terrain information. The TAWS/Windshear CCA will also provide a reactive windshear alert which meets the requirements of TSO-C117a. The windshear alert is active during take-off and final approach phases and produces aural and visual annunciations. The windshear alert measures vertical and horizontal components of air mass accelerations and determines if a windshear caution or warning should be generated. Windshear alert is not yet implemented; however, all current circuitry and processor will be utilized. 3.3.2 TCAS Functionality 3.3.2.1 Type of Emission 18MOP1D 3.3.2.2 Frequency Range 1030 + 0.01 MHz ACSS Use or disclosure of the information on this sheet is subject to the Page 5 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - 3.3.2.3 Power Rating 0.4 to 500 Watts Peak Effective Radiated Power (Pulsed) 3.3.2.4 Final Power Amplifier Solid State Balanced Amplifier (Class C) using two Motorola MRF10501 silicon bipolar transistors. 3.3.2.5 Active Device Functions Function Device Type Manufacturer Oscillator Temperature Compensated Crystal Oscillator (TCXO) 6206 Oscillatek Microwave Low Noise Transistor--Amplifier AT-41511 HP Transmitter Monolithic Amplifier VNA – 25 Mini-Circuit .1 Watt, Microwave Pulse Power Function Device Type Manufacturer Transmitter Transistor--Amplifier, MRF1000MB Motorola 1 watt Microwave Pulse Power Transistor--Amplifier, MRF10005 Motorola 5 watt Microwave Pulse Power Transistor--Amplifier, MRF10031 Motorola 30 watt Microwave Pulse Power Transistor--Amplifier, MRF10120 Motorola 150 watt Microwave Pulse Power Transistor--Amplifier, MRF10502 (2 ea) Motorola 500 watt Pulse Modulator N Channel FET IRFR220 Motorola Modulator N Channel FET IRFR9220 International Envelope Modulator Rectifier DPSK Modulator NPN Transistor (1) BSR14 Generic Modulator NPN Transistor (2) BSR16 Generic ACSS Use or disclosure of the information on this sheet is subject to the Page 6 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - Modulator 3.3.3 Circuit Diagram A block diagram and schematics will be provided with the FCC Form 731 when the application for certification is filed with the FCC. 3.3.4 Instruction Book An ACSS document, System Description and Installation Manual, 8000451-001, provides instructions for the proper installation of the T2CAS computer on a given aircraft. 3.3.5 Tune -up Procedure No field tuning is required. Alignment is performed in the factory. 3.3.6 Oscillator Circuit The 1030 MHz source consists of the following: 1.) a phase locked oscillator (PLO) is locked to a Temperature Compensated Crystal Oscillator (TCXO). The TCXO provides the required frequency stability for the 1030 MHz source. 2.) the output of the PLO is fed to a prescaler divider, which in turn provides the input to a multiplier circuit. 3.) the output of the multiplier is band pass filtered, and then amplified and distributed to both the receiver and transmitter circuits. 3.3.7 Frequency Stabilization Temperature Compensated Crystal Oscillator (TCXO). 3.3.8 Modulation Limiting Not Applicable 3.3.9 Radiated Interference Suppression At the output of the transmitter is a two-pole high power cavity filter designed to attenuate spurious created by the DPSK modulation. This filter also offers good rejection of the even harmonics of the carrier. Following the high power cavity filter is a five pole reflective microstrip low pass filter designed for maximum rejection of the 2 through 9 harmonics of the carrier nd th Transmitter Spectrum Low Pass Filter Filter The spectral output of the 1030 MHz transmitter will be limited to the following schedule: ACSS Use or disclosure of the information on this sheet is subject to the Page 7 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - Frequency difference Relative power (MHz from carrier) (dB below maximum) ≥ 4, < 6 6 ≥ 6, < 8 11 ≥ 8, < 10 15 ≥ 10, < 20 19 ≥ 20, < 30 31 ≥ 30, < 40 38 ≥ 40, < 50 43 ≥ 50, < 60 47 ≥ 60, < 90 50 ≥ 90 60 ACSS Use or disclosure of the information on this sheet is subject to the Page 8 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - 4 MODULATION DETAILS 4.1 ATCRBS Interrogations. Interrogations are sent out on an intentionally jittered 1+0.2 second interval in increasing power levels according to the schedules shown in Table 4, Table 5, and Table 6. By transmitting the weakest signals first only the closest aircraft will reply. The interrogations progress in a roughly circular pattern weighted toward the front of the aircraft since that is the area from which the greatest closing speeds originate. In areas of high density the sequence is halted when the computer has reached a limit defined by a complex set of three inequalities. In this manner, interference to other TCAS equipped aircraft in the area is minimized since the strongest interrogations are the first to be dropped. The priority of elimination of steps for interference limiting is also shown in Table 4, Table 5, and Table 6. This priority is inversely related to the order of the step sequence. Pulse Widths: 0.8 + 0.05 usec Rise Times (10% to 90%): ≥ 0.05 usec., < 0.1 usec Fall Times (90% to 10%): ≥ 0.05 usec., < 0.2 usec S1 P1 P3 P4 Pa Pb Figure 1: ATCRBS Interrogations Pulses P1, P3, and P4 will appear in all interrogation steps of the whisper / shout sequence and will be at the same power level. Pulse S1 will appear in all steps except the initial step on each antenna direction and at a level two or three dB below the level of P1, etc. according to the schedules shown in Figures 1 through 3. The steps occur at intervals of two milliseconds until the entire program is complete. The program length depends upon the individual aircraft installation. Options are available from using either an omni-directional bottom antenna or adirectional bottom antenna. The top antenna is always directional. Pulses Pa and Pb are transmitted on the antenna. They are used for suppression of sensitivity of the receiving aircraft to the indicated pulses: ACSS Use or disclosure of the information on this sheet is subject to the Page 9 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - S1 = -2 microseconds P1 = 0 microseconds PA = 2 microseconds PB = 19 microseconds P3 = 21 microseconds P4 = 23 microseconds 4.2 Mode S Interrogations Details of the Mode S interrogations are shown in Figure 2 below. The preamble and the synchronizing phase reversal (SPR) will appear the same in all interrogations. The data block will be either 56 or 112 chips of 0.25 microseconds, depending upon the type of reply desired. The data chips will be reversed phase from their previous chips if their data bid are 1, they will remain the same phase as the previous chips is their data bits are 0. The allowable transition time of the phase reversals is a maximum of 80 nanoseconds. The Mode S interrogations are transmitted after the whisper/shout sequence of ATCRBS interrogations. When no Mode S equipped aircraft are replying, the TCAS CU sends out Mode S broadcast interrogations based upon a 10 second pattern with 2 or 3 seconds between transmissions on the four lobes of the antenna. The time remaining after the Mode S transmissions are completed is used as a listening period for other unacquired aircraft. • Preamble Pulse Widths: 0.8 + 0.05 usec • Rise Times (10% to 90%): < 0.1 usec • Fall Times (90% to 10%): < 0.2 usec SPR P1 P2 P6 Figure 2: Mode S Interrogations Timing of the Mode S interrogations is as follows, referenced to the leading edge of the P1 pulse: P1 0.0 microseconds P2 2.0 microseconds P6 3.5 microseconds SPR 4.75 microseconds Bit 1 5.25 microseconds End P6 19.75 microseconds (56 bits) 33.75 microseconds (112 bits) Table 2: Mode S Interrogation Timing Omni-Directional Antenna ACSS Use or disclosure of the information on this sheet is subject to the Page 10 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - Nominal Power Levels (dB relative to full power) Level P1,P3, P4 Pulses S1 Pulse 00 -13 -16 01 -15 -18 02 -17 -20 03 -19 -22 04 -21 -24 05 -23 -26 06 -25 none Table 3: Mode S Interrogations, Omni-Directional Antenna Directional Antenna Nominal Power Levels (dB relative to full power) Level P1,P3, P4 S1 Pulse Pa, Pb Pulse D0 0 -3 -2 D1 -1 -3 -3 D2 -2 -5 -4 D3 -3 -5 -5 D4 -4 -7 -6 D5 -5 -7 -7 D6 -6 -9 -8 D7 -7 -9 -9 D8 -8 -11 -10 D9 -9 -11 -11 D10 -10 -13 -12 D11 -11 -13 -13 D12 -12 -15 -14 D13 -13 -15 -15 D14 -14 -17 -16 D15 -15 -17 -17 D16 -16 -19 -18 D17 -17 -19 -19 D18 -18 -21 -20 D19 -19 -21 -21 D20 -20 -23 -22 D21 -21 -23 -23 D22 -22 -25 -24 D23 -23 -25 -25 D24 -24 -27 -26 D25 -25 -27 -27 D26 -26 -- -16 (P4 only) Table 4: Mode S Directional Antenna Interrogation Transmission Levels ACSS Use or disclosure of the information on this sheet is subject to the Page 11 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - Bottom Omni-Directional Antenna Interference Limiting Priority / Interrogation Level 98 / 06 97 / 05 96 / 04 95 / 03 94 / 02 93 / 01 92 / 00 Top Directional Antenna Interference Limiting Priority / Interrogation Level 0’ 180’ 90’ 270’ 91 / D26 - - - 90 / D25 - - - 89 / D24 - - - 88 / D23 - 87 / D26 86 / D26 85 / D22 - 84 / D25 83 / D25 82 / D21 - 81 / D24 80 / D24 79 / D20 - 78 / D23 77 / D23 76 / D19 - 75 / D23 74 / D22 73 / D18 72 / D26 71 / D21 70 / D21 69 / D17 68 / D25 67 / D20 66 / D20 65 / D16 64 / D24 63 / D20 62 / D19 61 / D15 60 / D23 59 / D18 58 / D18 57 / D14 56 / D22 55 / D17 54 / D17 49 / D12 48 / D20 47/ D15 46 / D15 45 / D11 44 / D19 43 / D14 42 / D14 41 / D10 40 / D18 39 / D13 38 / D13 37 / D9 36 / D17 35 / D12 34 / D12 33 / D8 32 / D16 31 / D11 30 / D11 29 / D7 28 / D15 27 / D10 26 / D10 25 / D6 24 / D14 23 / D9 22 / D9 21 / D5 20 / D13 19 / D8 18 / D8 17 / D4 16 / D12 15 / D7 14 / D7 13 / D3 12 / D11 11 / D6 10 / D6 9 / D2 8 / D10 7 / D5 6 / D5 5 / D1 4 / D10 3 / D4 2 / D4 1 / D0 - - - (Interrogation sequence is right to left, top to bottom) Table 5: Top Directional / Bottom Omni-Directional Interrogation Sequence Interference Limiting Priority / Interrogation Level ACSS Use or disclosure of the information on this sheet is subject to the Page 12 Proprietary proprietary notice on the title page.

2 T CAS FCC Compliance Test Report SPEC NO: 8000709-001 REV LTR CAGE CODE: 1WYD3 - Top Directional Antenna Bottom Directional Antenna 0’ 180’ 90’ 270’ 0’ 180’ 90’ 270’ 113 / D26 - - - 112 / D26 - - - 111/ D25 - - - - 110 / D25 - - 109/ D24 - - - 108 / D24 - - - 107/ D23 - - - 106 / D23 - - - - - 105 / D26 104 / D26 - - 103 / D26 102 / D26 101 / D22 - - - 100 / D22 - - - - - 99 / D25 98 / D25 - - 97 / D25 96 / D25 95 / D21 - - - 94 / D21 93 / D26 - - - - 92 / D24 91 / D24 - - 90 / D24 89 / D24 88 / D20 - - - 87 / D20 86 / D25 - - - - 85 / D23 84 / D23 - - 83 / D23 82 / D23 81 / D19 - - - 80 / D19 79 / D24 - - - - 78 / D22 77 / D22 - - 76 / D22 75 / D22 74 / D18 - - - 73 / D18 - - - - 72 / D26 71 / D21 70 / D21 69 / D17 68 / D25 67 / D20 66 / D20 65 / D16 64 / D24 63 / D19 62 / D19 61 / D15 60 / D23 59 / D18 58 / D18 57 / D14 56 / D22 55 / D17 54 / D17 53 / D13 52 / D21 51 / D16 50 / D16 49 / D12 48 / D20 47 / D15 46 / D15 41 / D10 40 / D18 39 / D13 38 / D13 37 / D9 36 / D17 35 / D12 34 / D12 33 / D8 32 / D16 31 / D11 30 / D11 29 / D7 28 / D15 27 / D10 26 / D10 25 / D6 24 / D14 23 / D9 22 / D9 21 / D5 20 / D13 19 / D8 18 / D8 17 / D4 16 / D12 15 / D7 14 / D7 Interrogations 13 / D3 12 / D11 11 / D6 10 / D6 for each sector 9 / D2 8 / D5 7 / D5 6 / D5 that has a TA 5 / D1 4 / D9 3 / D4 2 / D4 or RA present 1 / D0 - - - . 1/ D17 1 / D23 1 / D21 1 / D21 1 / D16 1 / D22 1 / D20 1 / D20 1 / D15 1 / D21 1 / D19 1 / D19 1 / D14 1 / D20 1 / D18 1 / D18 1 / D13 1 / D19 1 / D17 1 / D17 1 / D18 1 / D16 1 / D16 1 / D17 1 / D15 1 / D15 1 / D16 1 / D14 1 / D14 1 / D15 1 / D13 1 / D13 1 / D14 1 / D13 (Interrogation sequence is right to left, top to bottom) Table 6: Top Directional / Bottom Directional Interrogation Sequence ACSS Use or disclosure of the information on this sheet is subject to the Page 13 Proprietary proprietary notice on the title page.


Document Created: 2003-02-18 07:17:13
Document Modified: 2003-02-18 07:17:13
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC