11 Sensors and Detection Overview

Updated: v2026.01.30

Aurora’s sensor and detection systems form an intricate web of signatures, sensors, and countermeasures. Before diving into the detailed mechanics of each component, this overview provides a conceptual framework for understanding how detection works and how to design effective sensor suites.

11.0.1 Detection Workflow Summary

Updated: v2026.01.30

Detection in Aurora follows a predictable sequence that every commander should understand:

Step 1: Target Generates Signatures

Every ship and installation produces detectable signatures based on its current state:

• Thermal Signature: Generated by engines (proportional to current speed) and a baseline idle signature (5% of hull size in HS) \hyperlink{ref-11.0-1}{[1]}
• EM Signature: Generated by active sensors, shields, and ECM when those systems are powered on
• Physical Cross-Section: The ship’s tonnage, detectable by active sensor sweeps regardless of emissions

Step 2: Sensors Attempt Detection

Your sensors compare their detection capability against the target’s signatures:

• Passive Thermal Sensors: Detect thermal signatures without emitting anything
• Passive EM Sensors: Detect EM signatures without emitting anything
• Active Sensors: Emit energy to detect physical cross-sections, revealing your position

Step 3: Resolution Matching

Each sensor has a resolution setting (tonnage class it is optimized for). Detection range scales based on how the target’s actual size/signature compares to the sensor’s resolution:

• Target larger than resolution: Full detection range
• Target smaller than resolution: Reduced range proportional to size ratio

Step 4: Contact Classification

Once detected, contacts provide varying levels of information:

• Passive detection reveals signature strength and approximate location
• Active detection reveals tonnage class and precise location
• Repeated observations build intelligence over time: each beam weapon firing reveals weapon type, power, and count; each missile launch reveals launcher count and size (see Section 11.1.4 Weapon Fire and Missile Launch Detection). ELINT modules provide additional intelligence-gathering capability (see Section 11.2.4 ELINT)

11.0.2 Sensor Type Decision Tree

Updated: v2026.01.30

Use this decision tree when designing ships or choosing which sensors to activate:

What do you need to detect?
|
+-- Ships under power, possibly silent (EMCON)?
|   --> Thermal Sensors (passive, no emissions)
|   |
|   +-- Large warships at extreme range?
|       --> High resolution (100+ HS / 5000+ tons)
|   |
|   +-- Small craft or missiles?
|       --> Low resolution (1-6 HS / 50-300 tons)
|
+-- Ships using active sensors or shields?
|   --> EM Sensors (passive, no emissions)
|   |
|   +-- Detecting enemy sensor pickets?
|       --> Match resolution to expected scout size
|   |
|   +-- Detecting shielded capitals?
|       --> High resolution for maximum range
|
+-- Silent, stationary targets?
|   --> Active Sensors (emits EM, reveals your position)
|   |
|   +-- Need to remain stealthy?
|       --> Accept limited detection capability
|   |
|   +-- Combat or pursuit situation?
|       --> Activate active sensors, accept detection
|
+-- Missiles or fighters specifically?
    --> Resolution 1-6 sensors (thermal, EM, or active)
    --> Consider dedicated missile detection sensors

Key Principle: Passive sensors keep you hidden but only detect emitting targets. Active sensors find everything but announce your presence.

11.0.3 Signature-to-Detection Cross-Reference

Updated: v2026.01.30

This table shows which sensor types can detect each signature type and the tactical implications:

Target State	Thermal Sig	EM Sig	Cross-Section	Best Detection Method
Under power, EMCON	High	Zero	Normal	Thermal sensor
Under power, sensors active	High	High	Normal	Any sensor type
Stationary, EMCON	Idle only (5% HS)	Zero	Normal	Active sensor
Stationary, sensors active	Idle only	High	Normal	EM sensor
Cloaked, under power, EMCON	Reduced	Reduced	Reduced	Thermal (degraded)
Cloaked, stationary	Minimal	Zero/Reduced	Reduced	Active (degraded)
ECM active	Variable	Present (jammer is electronic system) \hyperlink{ref-11.0-9}{[9]}	Normal	EM sensor
Shields raised	Variable	Very High (3x shield) \hyperlink{ref-11.0-2}{[2]}	Normal	EM sensor
Missile (active seeker)	Minimal	Seeker rating \hyperlink{ref-11.0-3}{[3]}	Small	EM sensor + Res-1 active
Missile (passive/semi-active)	Minimal	Zero	Small	Res-1 active sensor

Reading the Table:

• “High” means easily detectable at long range with appropriate sensors
• “Reduced” means cloaking device reduces the signature by its percentage
• “Idle only” means the 5% of HS baseline – very short detection range
• “Zero” means undetectable by that sensor type

11.0.4 Designing a Sensor Suite

Updated: v2026.01.30

A well-designed fleet requires sensors at multiple resolutions covering different detection modes:

Minimum Viable Coverage:

1. One thermal sensor (resolution matched to expected threats)
2. One EM sensor (resolution matched to expected threats)
3. One active sensor (for finding silent targets in combat)

Comprehensive Fleet Coverage:

Sensor Role	Type	Resolution	Purpose
Fleet search	Active	100-500 HS	Find capitals at extreme range
Escort detection	Active/Thermal	10-50 HS	Detect destroyers and frigates
Missile warning	Active/Thermal	1 HS	Detect incoming missiles
Picket detection	EM	10-50 HS	Find enemy scouts using active sensors
Silent approach	Thermal	Various	Detect targets without emitting

Design Questions:

1. What threats do you expect? Match resolution to enemy ship sizes
2. Will you operate offensively or defensively? Offense may accept active emissions; defense may prioritize stealth
3. Single ship or fleet operations? Fleets can distribute sensor roles across multiple hulls
4. Dedicated sensor ships or distributed sensors? Both approaches are viable in C# Aurora’s area-based model

11.0.5 Sensor Technology Priorities

Updated: v2026.01.30

Research priorities depend on your strategic situation:

Priority	Technology	Benefit
High	Thermal Sensor Sensitivity	Longer passive detection range \hyperlink{ref-11.0-4}{[4]}
High	EM Sensor Sensitivity	Better detection of active emitters \hyperlink{ref-11.0-5}{[5]}
Medium	Active Sensor Strength	Longer active detection range \hyperlink{ref-11.0-6}{[6]}
Medium	Cloaking Sensor Reduction	Better stealth if pursuing that doctrine \hyperlink{ref-11.0-7}{[7]}
Lower	Active Sensor Sensitivity	Marginal range improvements

C# Aurora Note: The area-based sensor model means extreme-range detection is harder to achieve than in VB6 Aurora. Multiple smaller sensors distributed across scouts are now strategically equivalent to monolithic sensor installations, so technology investments should consider fleet composition. \hyperlink{ref-11.0-8}{[8]}

Chapter Contents

Updated: v2026.01.26

• Section 11.1 Thermal and EM Signatures – How ships generate detectable emissions
• Section 11.2 Passive Sensors – Thermal and EM sensor mechanics
• Section 11.3 Active Sensors – Active sensor detection and fire control
• Section 11.4 Stealth – Cloaking, EMCON, and stealth tactics

Related Sections

• Section 8.4 Sensors – Sensor component design in ship designer
• Section 12.1 Fire Controls – Using active sensors as missile fire controls
• Section 12.5 Electronic Warfare – ECM effects on sensor range
• Appendix A: Formulas – Detection range calculation formulas

References

\hypertarget{ref-11.0-1}{[1]}. Aurora C# game mechanics – Idle thermal signature equals 5% of hull size in HS. A 200 HS (10,000-ton) ship produces idle thermal of 10. Confirmed via consistent community documentation and Appendix A.

\hypertarget{ref-11.0-2}{[2]}. Aurora C# game database (AuroraDB.db v2.7.1) – Shield_EM_Signature = Shield_Strength x 3. See FCT_TechSystem TechTypeID=16 for shield strength values. Cross-referenced with Appendix A ref-A-5.

\hypertarget{ref-11.0-3}{[3]}. Aurora C# game mechanics – Active homing missiles emit EM signature equal to their onboard sensor’s rating, making them detectable by EM sensors. (Forum-documented; not directly in database tables.)

\hypertarget{ref-11.0-4}{[4]}. Aurora C# game database (AuroraDB.db v2.7.1) – FCT_TechSystem TechTypeID=19 (Thermal Sensor Sensitivity): 12 levels from 5 (1,000 RP) through 75 (2,000,000 RP).

\hypertarget{ref-11.0-5}{[5]}. Aurora C# game database (AuroraDB.db v2.7.1) – FCT_TechSystem TechTypeID=125 (EM Sensor Sensitivity): 12 levels from 5 (1,000 RP) through 75 (2,000,000 RP). Identical progression to thermal sensitivity.

\hypertarget{ref-11.0-6}{[6]}. Aurora C# game database (AuroraDB.db v2.7.1) – FCT_TechSystem TechTypeID=20 (Active Grav Sensor Strength): 12 levels from 10 (1,000 RP) through 180 (2,000,000 RP), plus Conventional strength 2 (500 RP).

\hypertarget{ref-11.0-7}{[7]}. Aurora C# game database (AuroraDB.db v2.7.1) – FCT_TechSystem TechTypeID=154 (Cloak Sensor Reduction): 10 levels from 75% (4,000 RP) through 99.5% (2,000,000 RP).

\hypertarget{ref-11.0-8}{[8]}. Aurora Forums, “Sensor Model for C# Aurora” – Steve Walmsley described the area-based sensor model replacing VB6’s linear model. The sqrt-based formula creates diminishing returns for larger sensors. aurora2.pentarch.org

\hypertarget{ref-11.0-9}{[9]}. Aurora C# game database (AuroraDB.db v2.7.1) – Sensor Jammers and Missile Jammers are ElectronicSystem=1 in FCT_ShipDesignComponents (ComponentTypeID=20). Both types are 3 HS in size with ComponentValue equal to the jammer level. As electronic systems, they contribute to EM signature when active, but the exact EM output value is not stored in the database. (Exact EM contribution unverified – jammer EM output formula not directly represented in the database.)