Conclusion

The combination of a 1-dimensional wavefront sensor with non-redundant masking or slit speckle interferometry, using the wavefront data to carry out post-detection turbulence compensation in the data processing phase, promises a significant advance in high-resolution imaging at reasonable cost. An instrument such as MAPPIT 2 would be able to image bright objects of moderate complexity (greater than for present passive interferometric methods, but much less than HST), at the highest angular resolution obtainable from single telescopes.

There are several developments of this project which could follow at a later stage. The method would be well suited for use with an 8 or 10 m telescope, yielding correspondingly improved angular resolution. A larger number of lenslets would be required in the wavefront sensor and larger number of pixels in both wavefront and science detectors, although for the wavefront sensor this increase would be lessened if the site had better seeing. Another future possibility would be use with laser guide stars, which could provide the signal needed for the wavefront sensor even for stars fainter than 9 mag. But such a development would be of limited use, certainly for the imaging of complex objects, unless science detectors with much lower read noise also become available. If fast detectors with negligible read noise do become available, they would greatly extend the range of objects accessible to high resolution imaging as described here.

© Copyright Astronomical Society of Australia 1997