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Official Documentation

Scenario 1 - First Day

Duration: 25-35 minutes

Difficulty: Beginner

Mission Type: Station Familiarization

New Operator Orientation

Section titled “New Operator Orientation”

Date: Monday, 0800 Local

Station: Vermont Ground Station (VT-01)

Trainer: Charlie Brooks, Senior Operator

New Hire: You

Charlie’s Note

Section titled “Charlie’s Note”

Welcome to North Atlantic Teleport Services. I’m Charlie Brooks - I’ve been running this station for six years. I’m transferring to our European operations next month, which means I need to get you and two other new hires up to speed before I leave.

Today is observation only. TIDEMARK-1 is already online serving customer traffic - you’re not touching any controls. You’re learning what each panel shows, what the indicators mean, and what “normal” looks like. Tomorrow we’ll see if any of it stuck.

I don’t repeat myself, but the system will. If you need to review something, the Mission Brief and Dialog History buttons are on the left.

Let’s not waste time.

TIDEMARK-1 Operations Reference

Section titled “TIDEMARK-1 Operations Reference”

TIDEMARK-1 is an eight-year-old C-band maritime communications satellite operated by SeaLink Global Communications. It sits at 53°W geostationary orbit, providing broadband service to vessels operating between Newfoundland and the Caribbean.

The satellite is fully operational and serving active customer traffic. Your job today is to understand what healthy equipment looks like.

Frequency Allocation

Section titled “Frequency Allocation”
Parameter RF (MHz) LO (MHz) IF (MHz)
Beacon (Downlink) 4,175.5 5,250 (LNB) 1,074.5
Carrier (Downlink, TP-1) 3,718 5,250 (LNB) 1,532
Carrier (Uplink, TP-1) 5,943 7,000 (BUC) 1,057

Both local oscillators sit above their RF, so both conversions subtract: IF = LO - RF on the way down, RF = LO - IF on the way up (the BUC panel shows this as LSB, lower sideband).

Antenna Configuration

Section titled “Antenna Configuration”
Parameter Value
Azimuth 153.2°
Elevation 35.2°
Polarization About +18.8° (TIDEMARK-1 skew as seen from VT-01)
Tracking Mode Program-track

Vermont Station Equipment Status

Section titled “Vermont Station Equipment Status”

This is what operational equipment looks like. Memorize it.

Timing Reference

Section titled “Timing Reference”
Equipment Status Key Indicators
GPSDO Locked About 8 satellites in view (the count drifts by one as they rise and set), 3× 10 MHz outputs active

Receive Chain

Section titled “Receive Chain”
Equipment Status Key Indicators
LNB Powered, reference locked Noise temp: 43K, thermally stable
Spectrum Analyzer Configured for beacon Center: 1,074.5 MHz IF, Span: 2 kHz
RX Modem Locked QPSK, FEC 3/4, C/N ≥ 8 dB

Transmit Chain

Section titled “Transmit Chain”
Equipment Status Key Indicators
BUC Active, reference locked LO: 7,000 MHz (LSB), RF 5,943 MHz, not muted
HPA Transmitting 50 dBm (100 W) output, 10 dB backoff from the 60 dBm P1dB

System

Section titled “System”
Equipment Status Key Indicators
Antenna On target Program-track active, tracking TIDEMARK-1
Dashboard No warning or critical alarms (the info row “Signal(s) Detected” is normal) All systems nominal

Station Familiarization Checklist

Section titled “Station Familiarization Checklist”

Charlie will walk you through each item. Verify you can locate and read these indicators.

GPS Timing Tab

Section titled “GPS Timing Tab”
  • GPSDO lock status (Locked/Holdover/Unlocked/Off)
  • Satellite count
  • 10 MHz reference outputs

RX Analysis Tab

Section titled “RX Analysis Tab”
  • LNB power status
  • LNB noise temperature
  • LNB thermal stability
  • Tap Points configuration (RX IF selected)
  • Beacon signal on spectrum analyzer
  • Spectrum analyzer center frequency and span
  • RX Modem lock status
  • C/N ratio reading
  • I&Q constellation (tight clusters = healthy)
  • Payload Data Integrity (frame sync, CRC, Reed-Solomon)

TX Chain Tab

Section titled “TX Chain Tab”
  • HPA enable status
  • HPA backoff level
  • TX Payload Data (source, encryption, buffer)

ACU Control Tab

Section titled “ACU Control Tab”
  • Antenna tracking mode
  • Azimuth and elevation readings
  • Polarization setting

Dashboard Tab

Section titled “Dashboard Tab”
  • Alarm status summary
  • Equipment health indicators

Signal Flow Reference

Section titled “Signal Flow Reference”

Receive Path

Section titled “Receive Path”
Satellite → Antenna → LNB (RF→IF) → Coupler → Spectrum Analyzer
                                           → RX Modem → Data

Transmit Path

Section titled “Transmit Path”
Data → TX Modem → BUC (IF→RF) → HPA → OMT → Antenna → Satellite

Normal Operating Parameters

Section titled “Normal Operating Parameters”

These are Charlie’s benchmarks for healthy equipment:

Indicator Normal Warning Investigate
GPSDO Locked (green) Holdover (yellow) Unlocked (red)
LNB Noise Temp < 100K 100-150K > 150K
LNB Thermal Stable Fluctuating Climbing
Beacon Clear spike Weak/noisy Missing
RX C/N ≥ 8 dB 5-8 dB (locked, thin fade margin) < 5 dB (near the lock threshold: the modem shows Required Es/N0 5.0 dB; with Es/N0 about 0.8 dB above Raw C/N it acquires lock from about 4.7 dB C/N (Required 5.0 plus a 0.5 dB acquisition margin, less the 0.8 dB Es/N0 offset) and holds it down to about 3.7 dB)
Constellation Tight clusters Spreading Scattered
HPA Backoff 8-12 dB 3-7 dB < 3 dB
Alarms None Warning Critical

End of Briefing

Section titled “End of Briefing”

This is your first day. Charlie will guide you through the equipment panels and explain what you’re seeing. Pay attention - he’s not going to repeat himself, and in a few weeks you’ll be doing this alone.

The health check workflow follows a logical sequence:

  1. Timing first - GPSDO is the foundation
  2. Receive chain - LNB, spectrum analyzer, modem
  3. Transmit chain - BUC, HPA
  4. Antenna - Tracking mode, polarization
  5. Dashboard - Confirm no warning or critical alarms

Do this check at the start of every shift, after any anomaly, and whenever something feels off.

Welcome to NATS.