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Planetary Derotation

Mathematically compensate for planet rotation during long capture sessions to combine more data for higher SNR

How It Works

1

Capture multiple short videos within rotation limits (precise timestamps required)

2

Stack each video segment individually to create intermediate images

3

Software calculates rotation angle based on planetary ephemeris data

4

Each stacked frame is counter-rotated to a common reference time

5

Derotated frames are combined into a single high-SNR master image

6

Result shows features as if captured instantly with perfect seeing

7

Process works for Jupiter, Saturn, and any rotating body

Pro Tips

  • -Jupiter rotation limits WITHOUT derotation: 30s (14"+), 60s (10"), 90s (8"), 2-3min (6")
  • -WITH derotation: combine 20-30 minutes of Jupiter data for exceptional SNR
  • -Saturn slower: 4-6 minutes safe without derotation, hours possible with
  • -Mars: 24.6h rotation, usually not needed for typical capture durations
  • -SER format strongly recommended - per-frame timestamps essential for accuracy
  • -Derotation transforms planetary imaging - overcomes the rotation time limit

Related Algorithms

Weighted Quality Stacking
Your sharpest frames contribute most - ideal for variable seeing...
Intermediate
Local Quality Stacking
The AutoStakkert method - 30-40% more detail possible...
Advanced
Median Stacking
The safest choice - naturally rejects outliers and artifacts...
Beginner

Related Terms

Stacking

Combining multiple frames into a single high-quality image

Alignment

Registering frames so features overlap precisely

Frame Rate (FPS)

Number of frames captured per second

SER Format

Uncompressed video format for astronomy

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