# Reasoning Chain

## Dimension 1: GSD Achievability

### Fact Confirmation
All candidate systems achieve 10-20 cm/pixel GSD from 10km (Facts #5-#9, #15). The atmospheric limit is ~5cm (Fact #2), so all options are optics-limited (good — no wasted capability).

### Reference Comparison
Systems with higher zoom/longer FL can achieve finer GSD but can always zoom out to match training data (Fact #16). Higher-capability systems provide flexibility to zoom in for closer inspection of specific targets.

### Conclusion
All candidates pass the GSD requirement. Systems with higher resolution sensors (Z40K 25.9MP, Sony α7RV 61MP) provide significantly better spatial coverage per frame at the target GSD.

### Confidence
✅ High — based on verified calculations

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## Dimension 2: Image Quality for AI Model Reuse

### Fact Confirmation
The AI model was trained on 10-20 cm/pixel imagery from 600-1000m altitude (Fact #4). At that altitude, atmospheric path is short — images are sharp with high contrast. At 10km, haze reduces contrast (Fact #17).

### Reference Comparison
Larger sensors have better SNR and dynamic range, which partially compensates for atmospheric degradation:
- Full-frame (Sony α7RV): 3.76µm pixels, excellent SNR
- 1" sensor (RX10 IV): 2.41µm pixels, good SNR
- 1/2.3" to 1/2.8" (drone gimbals): 1.0-2.0µm pixels, limited SNR

Smaller pixels on drone gimbals mean each pixel gathers less light, amplifying atmospheric haze impact.

### Conclusion
For AI model reuse from 10km, larger sensors provide measurably better imagery. However, the practical impact depends on atmospheric conditions. In mostly sunny weather (user constraint), even small-sensor cameras may produce adequate results. Computational dehazing can bridge the gap. The Sony full-frame option offers the best margin of safety for image quality.

### Confidence
⚠️ Medium — depends on specific atmospheric conditions and AI model sensitivity

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## Dimension 3: Platform Integration

### Fact Confirmation
Viewpro cameras have documented serial (Viewlink) and TCP protocols (Fact #10). ArduPilot has native Lua driver. SIYI has serial protocol. DJI H30T is locked to DJI Matrice (Fact #7). Sony cameras have no native gimbal/serial integration.

### Reference Comparison
- Viewpro/Airmobi: Plug-and-play for custom platforms via UART/TCP. Best integration story.
- SIYI: Serial protocol available, community support in ArduPilot ecosystem.
- Sony + Gremsy: Gremsy T7 has MAVLink support, but camera zoom/photo control requires separate integration (USB/HDMI). More complex.
- DJI: Effectively impossible on non-DJI platforms.

### Conclusion
Chinese drone gimbal cameras (Viewpro, SIYI) offer the simplest path to balloon integration. Sony approach requires significantly more custom engineering. DJI is disqualified for this use case.

### Confidence
✅ High — based on manufacturer documentation and open-source drivers

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## Dimension 4: Balloon-Specific Stabilization

### Fact Confirmation
Balloon payloads experience continuous rotation and pendulum swinging (Fact #12). Active gimbal alone may be insufficient. All candidate gimbals have ±0.01° to ±0.02° vibration accuracy.

### Comparison
All integrated drone gimbals are designed for UAV vibration (high frequency, small amplitude). Balloon motion is different (low frequency, large amplitude rotation/swinging). The A40TR Pro has the tightest pointing accuracy (±0.005°) and MIL-STD certification.

For the Sony approach, the Gremsy T7 is at payload limit (3,140g vs 3,175g max) — this leaves almost no margin and the gimbal motors may struggle with balloon-specific motion compensation.

### Conclusion
All candidates need passive stabilization via suspension design (anti-rotation mechanism, pendulum dampers). The gimbal handles residual motion. The A40TR Pro has the best specifications for pointing accuracy. The Sony approach has gimbal weight margin concerns.

### Confidence
⚠️ Medium — balloon-specific testing required to validate

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## Dimension 5: Cost-Benefit Analysis

### Fact Confirmation
Budget: $30k. Options range from $2,299 to ~$10,850 for the camera system alone. Need to account for integration hardware, cables, power, and passive stabilization.

### Comparison
| Option | Camera System | Integration/Mounting | Passive Stabilization | Total Est. |
|---|---|---|---|---|
| A40 Pro | $2,299 | $500 | $1,000-2,000 | $3,800-4,800 |
| Z40K | $3,000-5,000 | $500 | $1,000-2,000 | $4,500-7,500 |
| SIYI ZT30 | $6,099-7,309 | $500 | $1,000-2,000 | $7,600-9,800 |
| A40TR Pro | $7,499-7,999 | $500 | $1,000-2,000 | $9,000-10,500 |
| Sony α7RV+800mm+T7 | $10,850 | $2,000-3,000 | $1,000-2,000 | $13,850-15,850 |

All options are well within $30k budget.

### Conclusion
There's significant budget headroom. The decision should be driven by image quality needs and integration simplicity rather than cost alone. Even the premium Sony option leaves >$14k for contingency and additional equipment.

### Confidence
✅ High — pricing from manufacturer sources

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## Dimension 6: Recommendation Reasoning

### For maximum simplicity and value: ViewPro Z40K ($3,000-5,000)
- 25.9MP resolution gives excellent ground coverage (606×453m FOV)
- 10.3 cm GSD at max zoom matches training data
- 4K video for review
- Documented serial protocol for custom integration
- Lightweight (~1kg)
- Leaves >$25k budget for spare units, integration, and contingency

### For maximum image quality: Sony α7RV + FE 400-800mm + Gremsy T7 (~$10,850)
- Full-frame sensor provides best atmospheric haze resilience
- Adjustable zoom from 400-800mm (9.4-4.7 cm GSD)
- 61MP resolution for highest detail
- Risk: weight at gimbal limit, complex integration, no turnkey zoom control

### For best balance of quality, features, and integration: A40TR Pro ($7,499-7,999)
- 40x zoom (170mm max) gives 11.6 cm GSD — within target
- MIL-STD-810H certification (-40°C to +55°C) — best environmental rating
- Thermal camera for night/low-visibility operation
- Laser rangefinder for target distance measurement
- ±0.005° pointing accuracy — tightest of all options
- Documented serial protocol
- Only 1.5kg

### For maximum versatility with multi-sensor: SIYI ZT30 ($6,099-7,309)
- 4 sensors (zoom, thermal, wide-angle, LRF)
- 12 cm GSD at max zoom — within target
- Lowest power consumption (9W average)
- Wide ArduPilot/PX4 community support
