Use Cases
Nanometric alignment
for segmented telescope mirrors
Summary
In Astronomical Precision, Microns Make All the Difference
Modern segmented mirror telescopes demand flawless alignment of hundreds of individual mirror pieces. Even the tiniest misalignment can distort images, limit resolution, and undermine the power of these extraordinary scientific instruments.
Achieving Real-Time, Micron-Level Mirror Alignment with FOGALE’s TILTRA Segment Alignment Measurement System
The challenge
Segmented mirrors, like those used in large telescopes, require continuous real-time adjustment to maintain perfect optical performance. Challenges include:
- Micrometric Alignment Requirements – Piston, tip, tilt, and gap must be controlled within tens of nanometers or microns.
- Thermal and Mechanical Drift – Environmental changes and telescope movements constantly disturb mirror positioning.
- Non-Invasive Measurement – Sensors must be lightweight, low-heat, and unobtrusive to avoid disturbing the delicate mirror structure.
- Scalability to Hundreds of Segments – Future telescopes require monitoring of hundreds or even thousands of segments in real time.
APPLICATIONS IN ASTRONOMICAL ENGINEERING
- Large Optical Telescope Alignment – Real-time adjustment of segmented primary mirrors.
- Adaptive Optics Calibration – Supports active control to compensate for dynamic atmospheric distortions.
- Research and Development – Critical data acquisition for improving mirror segment manufacturing and mounting techniques.
- Next-Generation Telescopes – Technologies scalable for new class instruments with thousands of segments.
The solution
FOGALE’s TILTRA is a high-precision capacitive or inductive sensing system specifically designed to measure and control the piston, tip, tilt, gap of segmented mirrors.
Proven on major projects , TILTRA delivers the accuracy and reliability needed for today’s most ambitious optical observatories.
Key Features:
- Capacitive or Inductive Multi-Electrode Sensors – Measure displacement directly between mirror segments at nanometer resolution.
- Remote Electronics Architecture – No heat dissipation near the mirrors; electronics are housed in separate enclosures (igloos).
- High Stability and Low Noise – Optimized for ultra-stable operation over long periods and across wide environmental changes.
- Real-Time Feedback – Complete computation of all alignment parameters every second, feeding directly into the control system.
- Scalable Design – Systems deployed with 480+ sensors and 20 electronic racks, demonstrating large-scale capability.
KEY ADVANTAGES OF THE SAMS SOLUTION
| Feature | Benefit |
|---|---|
| Parallel Edge Measurement | Real-time capture of piston, gap, tip, tilt without mirror disturbance |
| Flex Circuit Sensors | Minimal mass and no thermal load at segment edge |
| Ultra-High Resolution | 10 nm RMS resolution for piston, 50 nm RMS for gap measurement |
| Full System Scalability | Handles hundreds of sensors in complex mirror geometries |
| Proven Observatory Deployment | Successfully operational at the South African Large Telescope |
The results
FOGALE’s TILTRA system represents the state of the art in high-precision segmented mirror alignment. By using non-intrusive capacitive or inductive sensing with robust real-time control, TILTRA empowers the next generation of astronomical observatories to achieve unprecedented imaging performance.