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