ScopeAlign

📱 Overview

ScopeAlign is a professional Android application designed for precise polar alignment of equatorial telescope mounts using the drift alignment method.

By tracking a star's drift over time, ScopeAlign provides real-time guidance on how to adjust your mount's azimuth and elevation for perfect polar alignment.

✨ Key Features

🎯 Intelligent Star Tracking

• Biased Search Algorithm: Efficiently tracks stars even with significant drift
• Automatic Brightness Tracking: Adapts to varying star brightness
• Jump Detection: Detects manual mount corrections and resets tracking
• Debounce Protection: Prevents false readings during initial lock

📊 Adaptive Drift Measurement

🎨 Visual Feedback System

• Green Circle: Target star locked and tracking
• Red Circle: Origin point (where star started)
• Cyan Crosshair: Current star position
• Color-Coded Arrows: Show correction direction
  • 🟢 Green: Well aligned (±3px)
  • 🟡 Yellow: Minor correction needed (3-10px)
  • 🔴 Red: Correction required (>10px)

⚙️ Smart Exposure Control

• Initial: 400ms for easy star selection
• Range: 8ms - 2000ms automatic adjustment
• Target Brightness: Maintains optimal Y-value (240-480)
• Smooth Transitions: Prevents sudden changes

🌍 Internationalization

• English: Default language (fallback)
• German: Full translation
• Auto-Detection: Uses phone's system language

🧪 Beta Testing Phase

📦 Installation

Standard Installation (APK)

1. Download the ScopeAlign APK file from the download section
2. Enable "Install from unknown sources" in your Android settings:
   • Settings → Security → Unknown Sources (enable)
   • Or: Settings → Apps → Special Access → Install unknown apps
3. Open the downloaded APK file
4. Follow the installation prompts
5. Grant camera permission when requested

📖 How to Use ScopeAlign

Step 1: Setup

1. Mount your smartphone on your telescope mount (parallel to the optical axis)
2. Perform rough alignment using a compass or polar scope
3. Launch ScopeAlign and grant camera permission
4. Configure star position via Settings button:
   • South: For azimuth alignment
   • East/West: For elevation (altitude) alignment

Step 2: Camera Alignment Check

1. Tap Start - An info dialog appears
2. Verify alignment:
   • Hold smartphone horizontally
   • Rotate mount
   • Star should move HORIZONTALLY on screen
   • If star moves diagonally → adjust phone angle
3. Tap OK when alignment is correct

Step 3: Star Selection & Tracking

1. Point telescope at a bright star near celestial equator
2. Wait for star to appear on screen
3. Tap on the star to lock tracking
4. Watch the overlay:
   • 🟢 Green circle: Locked target
   • 🔴 Red circle: Origin point
   • 🔵 Cyan crosshair: Current position

Step 4: Drift Measurement

The app now tracks the star's drift and provides real-time correction guidance:

Step 5: Correction

Based on star position and drift direction, the app shows:

For South Star (Azimuth):

• Azimuth → EAST: Turn mount east (right)
• Azimuth → WEST: Turn mount west (left)
• ✓ Well aligned: Drift within acceptable range

For East/West Star (Elevation):

• Elevation HIGHER: Raise mount's elevation
• Elevation LOWER: Lower mount's elevation
• ✓ Well aligned: Drift within acceptable range

Step 6: Iteration

1. Make adjustment based on displayed correction
2. Wait for app to detect change and reset
3. Repeat until "✓ Well aligned" is shown
4. Switch star position (South ↔ East/West) and repeat for other axis

Stop Button Behavior

• During tracking: Stops tracking immediately (no confirmation)
• When idle: Shows exit confirmation dialog
• Android Back button: Same behavior as Stop button

❓ Frequently Asked Questions

General Questions

Q: How accurate is ScopeAlign?

A: ScopeAlign uses the drift alignment method, which is capable of sub-arcminute accuracy. Actual accuracy depends on:

• Stability of mount and phone attachment
• Atmospheric conditions (seeing)
• Star brightness and camera quality
• Time spent measuring drift

Q: Do I need GPS or internet?

A: No! ScopeAlign v2.0 works completely offline and does not require GPS. All calculations are done locally on your device using camera data only.

Q: Which stars should I use?

A: Best results with:

• Bright stars (magnitude 2-4)
• Stars near celestial equator (declination -20° to +20°)
• Stars on or near meridian
• Avoid very bright stars (may cause blooming)

Q: How long does alignment take?

A: Typical alignment session:

• Initial rough alignment: 5-10 minutes
• Per drift measurement: 10-40 seconds (depending on drift magnitude)
• Total fine alignment: 15-30 minutes for both axes
• Repeat measurements: 2-4 iterations per axis typical

Troubleshooting

Q: App can't find/track the star

A: Try these solutions:

1. Use a brighter star
2. Wait for initial exposure to adjust (shows current exposure in ms)
3. Tap directly on the star center
4. Ensure phone is mounted stably
5. Check that nothing is blocking camera lens

Q: Tracking keeps resetting

A: This usually means:

• Mount vibration is too high (star appears to jump)
• Jump threshold exceeded (50px movement detected)
• Need more stable mounting of phone
• Wind or external vibrations affecting mount

Q: Stars are too dim/bright

A: The app automatically adjusts exposure, but:

• Initial exposure is 400ms (may need a few seconds to adjust)
• Very bright stars: Exposure will go down to 8ms minimum
• Very dim stars: Exposure will go up to 2000ms maximum
• Watch exposure indicator: shows current exposure time

Q: Correction arrows don't match my expectations

A: Remember:

• Check Settings: Is star position (South/East/West) correctly set?
• Verify camera alignment: Star should move horizontally when mount rotates
• Phone orientation matters: Keep phone horizontal
• Wait for enough samples: Don't trust corrections with <15 samples

Technical Questions

Q: Can I use this for other telescope mounts?

A: ScopeAlign works with any equatorial mount (German equatorial, fork, etc.). It does NOT work with alt-azimuth mounts as they don't require polar alignment.

Q: Why does my phone get warm?

A: Continuous camera use and real-time image analysis are CPU-intensive. This is normal during operation.

Q: What camera features are used?

A: ScopeAlign uses:

• Manual exposure control (8ms - 2000ms)
• YUV image format for brightness analysis
• Full resolution rear camera
• No digital zoom, no flash, no autofocus

Advanced Usage

Q: Can I use this for permanent pier alignment?

A: Absolutely! ScopeAlign is perfect for:

• Initial pier installation
• Seasonal re-alignment
• Verification of existing alignment
• Adjustment after pier settling

Q: How do I interpret the numbers?

A: Status line breakdown:

Lock: Y=125  Δ(2,1)  Drift:12px/40s  Rot=90°

Y=125:      Current star brightness (Y-channel)
Δ(2,1):     Delta from origin (x=2px, y=1px)
Drift:12px: Drift magnitude over measurement window
/40s:       Measurement window duration
Rot=90°:    Camera rotation (usually 90° or 270°)

💬 Support & Community

Getting Help

• 📧 Email: ScopeAlign@ruthner.at
• 📖 Documentation: This page and in-app help

📝 Changelog

Version 2.0 (Current)

• ✨ Complete rewrite with intelligent tracking
• 🎯 Biased search algorithm for robust star tracking
• 📊 Adaptive drift measurement (10-40 second windows)
• ⚡ Smart auto-exposure (8ms - 2000ms)
• 🎨 Color-coded correction arrows
• 🌍 Multi-language support (English, German)
• 🛑 Intelligent Stop button (context-aware)
• 🔍 Jump detection and auto-reset
• 📱 Modern UI with professional branding
• 🗑️ Removed unnecessary GPS dependency