Disclaimer: The following is an academic exercise and the information below was obtained through open-source, unclassified platforms and research.

Excuse any overlooked formatting issues; this was brought over from my original Microsoft Word document. This is a more robust TSA format.

Target Identification

Field	Entry
Target Name	Longpo Naval Base (Greater Yulin)
Target Type	Naval Base, Submarine and Surface Fleet Operating Complex
Country	People’s Republic of China (PRC)
General Location	Yalong Peninsula, near Sanya, Hainan Island
Coordinates	18.207278, 109.69472 (central base reference)
Data Sources	Commercial satellite imagery, open-source reporting
Intended Use	Unclassified training ETF; academic support to targeting product
Summary Assessment	High-readiness, permanently manned naval operating complex supporting submarine and surface vessel sustainment, with indicators of hardened subsurface infrastructure and localized air defense.

Executive Overview

Longpo Naval Base is assessed as a high-readiness, permanently manned, multi-mission naval installation supporting both submarine and surface fleet operations for the PLA Navy (PLAN) in the South China Sea. Integrated commercial satellite imagery confirms simultaneous submarine berthing, surface vessel sustainment, active cantonment and training functions, and probable subsurface infrastructure operations, indicating continuous operational use.

The target system is designed to enable survivability, sustained force generation, and rapid employment, combining hardened underground facilities, dedicated submarine and surface piers, extensive personnel housing, training infrastructure, and layered force protection within a geographically constrained coastal environment.

System Purpose and Function

The primary purpose of the Longpo Naval Base system is to:

• Support nuclear and conventional submarine operations (berthing, sustainment, concealment)
• Enable surface fleet support and staging
• Provide organic personnel housing, training, command, and logistics sufficient for continuous operations
• Increase survivability through terrain masking, vegetation concealment, and hardened subsurface facilities

Integrated System Description

Maritime Operations and Berthing

Recent imagery confirms:

• Multiple submarines docked at dedicated submarine piers, consistent with active maintenance or deployment cycles
• Surface vessels berthed at northern and primary piers, assessed as surface combatants or naval auxiliaries
• Pier layout and vessel separation indicate purpose-built military infrastructure, not dual-use (commercial) facilities

Concurrent submarine and surface vessel presence indicates active operational tempo and coordinated mission support.

Subsurface and Hardened Infrastructure

Imagery analysis identifies multiple indicators consistent with underground facilities, including:

• Suspected subsurface access or support portals embedded in terrain
• Ventilation structures indicative of underground airflow management
• Road configurations suitable for service vehicles rather than civilian use
• Vegetation concealment and standoff from cantonment areas

These features align with known PLA practices for submarine survivability, protected maintenance, and ISR mitigation, and are assessed to support the underground submarine complex associated with Greater Yulin.

Personnel, Cantonment, and training Infrastructure

Integrated imagery shows a large, permanent personnel support complex including:

• Barracks and housing clusters
• Administrative and headquarters buildings likely to support C2
• Multiple training facilities, including running tracks, athletic fields, and courts
• Deliberate functional separation between personnel zones and waterfront operations

The scale and permanence of these facilities support assessment of continuous manning and high readiness.

Logistics, Sustainment, and Internal Mobility

The base is assessed as highly likely to include warehousing and support buildings for logistics and services, an internal road network optimized for controlled movement, and vehicle access patterns supporting movement between cantonment, logistics, subsurface, and pier areas. These elements allow for sustained operations without reliance on immediate external resupply.

Force Protection and Site Design

The overall site layout indicates a layered force protection approach:

• Facilities are embedded in dense vegetation and complex terrain
• Limited access points and internal zoning
• Spatial dispersion to reduce single-point personnel or mission vulnerability
• Proximity to defensive coastal geography and controlled maritime approach

Critical Nodes and System Dependencies (Training Assessment)

Key dependencies within the target system include:

• Submarine piers and support infrastructure
• Suspected subsurface access and ventilation nodes
• Personnel cantonment and training areas (establishes readiness)
• Internal road and service networks linking all subsystems

Disruption or degradation of these elements is likely to reduce sortie generation, sustainment capacity, and/or readiness over time.

Indicators and Warnings

Established baseline and surge indicators include:

• Increased submarine or surface vessel counts
• Heightened activity near subsurface access points
• Increased vehicle density along internal roadways
• Expanded use of training facilities or personnel movement
• Construction or modification near suspected underground nodes

Overall Assessment

Longpo Naval Base functions as a core operational hub for PLAN submarine and surface forces in the South China Sea. Integrated commercial imagery shows the base is actively supporting maritime operations, personnel readiness, and survivability through hardened infrastructure. The system is optimized for endurance, concealment, and rapid deployment, making it a strategically significant naval installation within China’s near-peer force posture.

Analytic Confidence: Moderate to High. External layout, functional zoning, and operational activity are well supported by commercial imagery; internal subsurface capacity and specific mission details remain less certain without additional corroboration.

Annexes

Annex I: Enemy Course of Action (COA) Table

COA #	Assessed PLAN COA	Indicators	Implications for Target System
COA 1	Maintain steady-state operations	Stable pier usage; routine training; normal personnel movement	Sustains baseline readiness
COA 2	Surge naval operations	Increased vessel counts; expanded pier use; elevated traffic	Higher operational tempo
COA 3	Disperse and conceal assets	Shortened pier dwell time; subsurface access activity	Improved survivability
COA 4	Increase force protection	Activity at AA/SAM sites; access restrictions	Reduced ISR effectiveness
COA 5	Shift C2 or sustainment	Changed logistics routes; admin redistribution	Increased redundancy
COA 6	Conduct signaling operations	Visible deployments; state media coverage	Deterrence and messaging

COA Assessment

PLAN activity is likely to remain at COA 1 absent regional escalation. COAs 2-4 are increasingly likely during elevated tensions, consistent with base design emphasizing survivability and sustained operations

Analytic Confidence: Moderate

Annex II: Node and Dependency Table

Node ID	Node	Function	Indicators	Criticality
N1	Submarine piers	Submarine berthing and sustainment	Submarines docked; pier utilization	High
N2	Surface Vessel Piers (North)	Surface fleet berthing and support	Surface vessels present	High
N3	Primary Surface Berth	Large vessel sustainment or staging	Large hull vessel docked	Med-High
N4	Cantonment (Barracks/Housing)	Personnel sustainment	Dense residential blocks	Med-High
N5	Admin/Command facilities	Base C2 and coordination	HQ buildings; road access	High
N6	Training Facilities	Force readiness	Tracks; athletic fields	Medium
N7	Logistics/Support Area	Stores, maintenance, services	Warehousing; service roads	High
N8	Internal Road Network	Internal movement and control	Wide roads; limited access points	Med-High
N9	Suspected Subsurface Access	Underground facility access/support	Hardened terrain-cut structure	High
N10	Suspected Ventilation Node	Subsurface airflow/support	Vent-like rooftop features	Med-High
N11	Suspected AA/SAM Site	Local air defense	Dispersed clearings; emplacement layout	Med-High

Dependency Summary (Condensed)

• Maritime access: Required for operational throughput at N1-N3
• Personnel sustainment: Dependent on N4, N6, N7
• Internal mobility: Enabled by N8 linking all nodes
• Survivability: Supported by N9-N11 through concealment and defense
  

Annex III: Priority Intelligence Requirements (PIRs)

PIR #	PIR	Tied Nodes	Why it Matters?
PIR 1	What submarine and surface vessel types and quantities are present, and what are the rotation patterns over time?	N1, N2, N3	Establish baseline v. surge posture, infer operational tempo
PIR 2	What indicators confirm active use of subsurface infrastructure (access, maintenance, or storage), and how frequently is it used?	N9, N10	Determines survivability and protected sustainment capacity
PIR 3	Where are the primary logistics sustainment points (warehousing, maintenance, fuel transfer areas), and what activity indicates surge resupply?	N7, N8	Identifies sustainment capacity and constraints
PIR 4	What is the functional hierarchy of the command and administrative area, and what redundancy exists across Greater Yulin nodes?	N5	Clarifies C2 resilience and operational coordination
PIR 5	What force protection posture is observable, including air defense presence, and what changes indicate increased readiness?	N8, N11	Supports I&W and resilience assessment
PIR 6	What linkages exist between cantonment/training areas and operational nodes, and do patterns indicate surge manning?	N4, N6, N8	Validates readiness cycles and manpower availability

Disclaimer: The following is an academic exercise and the information below was obtained through open-source, unclassified platforms and research.

Excuse any overlooked formatting issues; this was brought over from my original Microsoft Word document. This is a more concise TSA format.

Field	Entry
Target Name	Subi Reef Airfield
Target Type	Expeditionary Airbase/Forward Air Operations Hub
Country	People’s Republic of China (PRC)
General Location	Subi Reef, Spratly Islands, South China Sea
Coordinates	10.9236 N, 114.0340 E (runway midpoint reference)
System of Interest	Integrated airfield system enabling aircraft launch, recovery, sustainment, and local C2
Data Sources	Commercial satellite imagery, open-source reporting
Operational Role	Supports air operations, ISR, logistics, and regional presence in the South China Sea
Primary Functions	Sortie generation, aircraft sustainment, fuel and logistics support, airspace control
Characteristics	Single long runway, centralized fuel and support infrastructure, maritime resupply dependency
Intended use	Unclassified training ETF; academic support to targeting product
Summary Assessment	Subi Reef Airfield functions as a forward-deployed air operations node with limited redundancy, reliant on a single runway, centralized sustainment systems, and maritime logistics for continued operations

Executive Overview

Subi Reef Airfield functions as an expeditionary air operations hub supporting PRC aircraft generation, sustainment, and local C2 for maritime and air activities. Key vulnerabilities are the single runway configuration, centralized fuel storage and distribution, and primary C2/ATC nodes. Short-term effects from degrading these nodes would reduce sortie generation and situational awareness; long-term logistics interdiction could degrade sustained operations. Primary Priority Intelligence Requirements (PIRs) focus on resident aircraft types and numbers, fuel and munitions capacities and locations, and C2/resilience measures.

System of Interest (SoI)

System Purpose

Enable launch, recovery, maintenance, sustainment, and command of air operations from Subi reef. The SoI includes the airfield surface (runway, taxiways, apron), aircraft support (maintenance, fuel, munitions), C2/ATC, logistics (pier, resupply nodes), utilities (power, desalination), and force protection (air defense, perimeter sensors).

Functional Breakdown/Subsystems

• Flight Operations: Runway, taxiways, aprons, aircraft hardstands, visual/precision approach aids, and emergency response. The single long runway appears to be the main sortie generation surface.
• C2/Air Traffic: Control tower or ATC shelter, local radar or approach aids, datalinks, and satellite terminals that coordinate launches and airspace deconfliction.
• Sustainment and Logistics: Fuel farm/tankage, refuel trucks, maintenance hangars, munitions storage (likely to be dispersed if present), and seaport for resupply.
• Power and Base Support: Generator clusters, fuel for generators, water/desalination systems, billeting, and administrative compounds.
• Force Protection and Sensors: Point and area air defenses, short-range AD systems, perimeter observation posts, and camouflage or hardening measures.

Critical Nodes and Single Points of Failure

• Runway strip: Single point for sortie generation; damage or contamination halts fixed-wing operations until repaired. Runway damage immediately reduces sortie generation; light surface damage is typically repairable in hours to days, while heavy crater or structural damage will require specialized engineering solutions and could take days to weeks to restore.
• Primary fuel storage/distribution: Limits sortie endurance and sortie turnaround capacity. Disruption of primary fuel storage or distribution channels would have an immediate impact on sortie endurance and turnaround rates and would degrade power generation as generators draw from the same supply.
• Primary C2/ATC node(s): Loss reduces safe launch or recovery and degrades operational tempo. Degradation of C2 and ATC nodes would sharply reduce safe flight operations, increase sortie spacing, and hinder coordinated ISR or strike integration.
• Supply pier/logistics offload point: Interdiction disrupts sustainment and heavy equipment supply. Interdiction of logistics flows to the pier or offload points would produce cumulative effects over weeks as munitions, spare parts, and fuel stocks decline.
• Power generation: Power loss affects communications, refueling systems, and lighting.

Priority Intelligence Requirements (PIRs)

The following PIRs identify the highest value questions necessary to understand Subi Reef Airfield’s operational posture and to inform collection and planning:

• What aircraft types and numbers are resident, transient, or routinely operating from the airfield?
• Where are the primary fuel and munitions storage locations and what are their capacities and hardening levels?
• What are the locations and redundancies of primary C2, ATC, and communications nodes?
• What logistics routes, both air and maritime, sustain the island and at what cadence and tonnage?
• What force protection systems, including radars and surface-to-air systems, are deployed in and around the reef along with their approximate engagement footprints?

These PIRs should be prioritized for collection tasking to close critical intelligence gaps and to refine estimates of repair timelines and sustainment vulnerabilities.

Collection Priorities and Methods

• IMINT (commercial satellite): Frequent tasking to track aircraft presence, construction and hardening, fuel truck movement, pier activity, and new defensive emplacements.
• SIGINT: Monitor airfield communications, ATC chatter, datalink emissions, and radar signatures to identify C2 nodes and defensive system activation.
• Maritime monitoring (AIS, SAR): Track resupply patterns and logistics ships servicing the reef.
• OSINT: Contractor or engineering reporting, procurement anomalies, and open imagery.
• HUMINT: Ground exploitation and assessment teams for on-site verification and munitions or fuel capacity confirmation post-event.

Battle Damage Assessment Metric and Indicators

BDA for Subi Reef Airfield will focus on observable indicators that reveal changes in operational capacity and recovery activity. Key measures include variations in sortie rates and visible aircraft counts on aprons, as these will reflect the airfield’s ability to generate and sustain flight operations. Imagery revealing runway repairs, temporary matting, or resurfacing indicates the tempo and efficiency of engineering recovery. Monitoring the frequency of fuel truck activity, visible fuel levels in storage tanks, and the return of ATC transmission or radar emissions provides insight into logistics and command restoration. Lastly, the arrival of logistics ships, the scale of offload operations at the pier, and renewed construction activity will serve as strong indicators of the airfield’s recovery status and resilience over time.

Recovery Estimates (High Level)

• Runway light damage – hours to repair using local crews and materials.
• Runway crater or heavy structural damage – days to weeks depending on matting/module availability and engineering support.
• Fuel node replacement or resupply – days to weeks depending on logistics access.
• C2 restoration via alternate datalinks – hours to days if redundant terminals exist; longer if critical hardware is destroyed.

Legal and Strategic Considerations

All analysis and any recommended engagements need to comply with the Law of Armed Conflict (LOAC), applicable Rules of Engagement (ROE), and Joint Force Commander (JFC) guidance. Special consideration needs to be given to dual-use infrastructure and collateral risk to maritime traffic and neutral parties in the South China Sea.

Analytic Confidence

Moderate confidence: imagery and open-source data provide clear external layout and construction indicators; internal capacities like fuel tank volumes, munitions types, and specific aircraft counts remain estimates without corroborating SIGINT and/or HUMINT.