25-March-2007: MAD successfully closed the MCAO loop on the sky

The dream is now a reality: on the night of March 25th MAD has closed the MCAO loop on the sky. After few preliminary checks to verify the functionality of the system we pointed at the open cluster NGC3293, we selected the guide stars and we closed the  MCAO loop. It worked immediately without any technical problem or delay. It is a great success for the MAD project and the whole MAD team that worked hardly in the past years to achieve such an outstanding milestone. The job is not done yet, we have several nights and two additional runs to characterize the system and to obtain the best information on the its correction capabilities. Surpises have still to come! For more details look at the ESO Press Release.

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18-January-2007: MAD been granted 3 observing runs at VLT in 2007

2007 will be a magic year for MAD. The demonstrator will be installed at the Nasmyth platform of the VLT Unit Telescope 3 (Melipal) to perform extended on-sky observations. MAD will benefit from 3 observing runs the firts in March/April, the second in May/June and the third in September.
During the observing runs both Multi-Shack-Hartmann WFS and Layer Oriented WFS will be used for evaluating the correction performance on different astronomical targets under changing seeing conditions.
MAD is now experiencing its last days in Garching and it will be dismounted starting from mid January to be shipped to Paranal Observatory by end of the same month. On mid February the integration and testing phase will start in order to be ready for the first official observing night scheduled on March, 26th.

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22-December-2006: MAD Preliminary Acceptance Europe successfully passed

In the last two weeks MAD underwent to the rigid procedure of the Preliminary Acceptance Europe, the ESO formal verification about the compliance for all the imposed standards before the installation at the Paranal Observatory. Several items have been carefully checked: optical and mechanical interfaces with the VLT Unit Telescope, safety hazard for personnel and instrumentation compliance, electronics standards compliance, electromagnetic compatibility compliance, control software compliance and final MCAO performance verification. The full MAD system has been declared compliant for the installation and operation at Paranal Observatory. The Paranal installation is planned for mid February 2007.

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18-August-2006: Document on CAMCAO+MAD detection performance released

A document describing the detection performance of the CAMCAO+MAD system has been released. This document can be used as an exposure calculator when observing with MAD on the sky but it intends only to give a general impressionn on what are the imaging capabilities of the system. You can click here to download the document.

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21-June-2006: MAD one direction optimization with 1 DM performed

Another important milestone has been achieved by MAD: one direction optimization with 1 DM loop closed!

Theory predicts that, if a simple model of the atmospheric turbulence profile is known, it is possible to enhance the AO correction on a specific direction of the FoV using only one DM conjugated to the ground, provided that the wavefront is sampled using NGS surrounding the FoV.
This kind of correction is cosidered very useful for several AO applications such as Multi-Object AO (MOAO) or Laser Tomogrpahy AO (LTAO).
Both techniques are considered strategic for the future European ELT and for this reason MAD has been asked to implement and demostrate this kind of correction.
In the specific test we have built a reconstructor able to merge the signals from 3 Guide Stars (GS) on a circle of 2 arcmin and to provide commands to the DM conjugated to the ground for correcting on-axis (FoV center) where no GS is located (all at 1 arcmin distance).
In the picture below a summary of the results obtained is shown. We compared the obtained PSFs with the ones produced by GLAO and MCAO correction both at the FoV center and on its surroundings. The difference in correction with respect to GLAO is remarkable and the performance are closer to the ones of MCAO.
These results are still preliminary and do not represent the final perfomance of MAD in this mode.


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25-May-2006: MAD results at Orlando SPIE

The full characterization of MAD in SCAO, GLAO and MCAO has been completed for bright flux

The first months of 2006 were very important for the MAD system. MAD has been fully characterized for bright flux NGS (mv=9) in all the correction modes in the Star Oriented configuration. The results are very exciting and partially confirm the performance predicted by numerical simulations. On the other hand the results have shown an unexpected behavior of the MCAO correction which appears to be better in uniformity than the one simulated. The analysis of the results is still going on and new laboratory tests are running.

The MAD results have been presented at the SPIE conference in Orlando. The PDF version of the paper can be downloaded here.

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02-October-2005: MAD Multi-Conjugate 1^st Closed Loop

MAD reached the full functionality: the MAD MCAO loop has been closed!

First preliminary results for the different MAD modes. The gains in peak intensity and encircled energy (EE) w.r.t the seeing in K band are shown. The morfological differences between the guide stars are due to not well corrected filed static aberrations.	Guide Stars configuration for the different MAD modes.

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03-June-2005: MAD Ground Layer Conjugate 1^st Closed Loop

Another step toward MCAO correction: the MAD GLAO had its first light!

MAD has closed the GLAO loop using three SH WFS located on a circle of 1.5 arcmin at the vertex of an equilateral triangle and the correction was applied through the ground conjugated DM. Only one rotating phase screen located at 6 Km altitude has been used to simulate a gentle anisoplanatism with the seeing was 0.45" in V Band and the wind speed 10 m/s. This fairly good seeing was intentionally produced in order to have a quick preliminary check of the functionalities of the MAD system in GLAO configuration. On the other hand this result was obtained without any particular optimization and we foresee significant margins of improvement which will be explored during the test phase. The loop was closed at a frequency of 115 Hz on m_V=6 star and the correction was imaged in K Band (2.2 um).
The FWHM in K band has been reduced by a factor ~2.5 demonstrating by fact that MAD is capable to perform GLAO correction (see the left picture below). The gain in Encircled Energy is shown in in the right picture below: at the level of the FWHM of the closed loop image the gain of energy concentration has increased by a factor ~2.

First MAD Ground Layer conjugate closed loop	Encircled Energy enhancement with GLAO correction

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02-March-2005: MAD Single Conjugate 1^st Closed Loop

A major Milestone has been achieved for the MAD project!

MAD closed the loop in the Single Conjugate configuration using one Shack-Hartmann WFS and one Deformable Mirror.
The atmospheric turbulence was simulated using a rotating Phase Screen miming a Kolmogorov turbulence of 0.4" seeing in V band moving at 10 m /s. This fairly good seeing was intentionally produced in order to have a quick preliminary check of the functionalities of the MAD system. On the other hand this result was obtained without any particular optimization and we foresee significant margins of improvement which will be explored during the test phase.
The loop was close at 115 Hz simulating a m_V=6 star and the correction was imaged in K Band (2.2 um). The resulting Strehl is 52%.
The PSF in open and closed loop imaged at 2.2 um and a movie showing the transition between open and closed loop are displayed below.
The cross-shaped artefact in the closed loop image is due to non optimal filtering of some bad seen modes.

First MAD single conjugate closed loop	Closed Loop Movie

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25-Nov-2004: one year later the MAD bench is close to completion
One year after the MAD bench installation in the ESO optical laboratory the integration is going close to the completion. Even is some items are still not integrated (optical derotator, Layer Oriented WFS,...) the MAD system reached the minimum conditions of operability.
In the picture below are shown a overall view of the MAD bench including the supporting structure for the cover, a close view of the Deformable Mirror area and a close view of the Shack-Hartmann area.

The MAD bench in advanced state of integration	Close view of the Deformable Mirrors area	Close view of the Shack-Hartmann WFS area

Some important system tests have been already strated in order to characterize MAD in its optical properties. One of the most relevant test regards the calibration of the non-common aberration in the IR path. We used the technique of Phase Diversity to estimate the aberration on-axis of the full IR path including the IR camera and we corrected for them using the ground conjugated deformable Mirror. The aberration estimation is retrieved via the analysis of focussed and out of focus images of an unresolved light source. In our case the IR camera has been use to record the images and, up to a certain extent, the camera was acting as a wavefront sensor.
In the picture below is shown the improvement of the PSF after the estimation of the aberration and the correction with the DM. The images have been obtained in K narrow Band (2.188 um) and the Strehl values are refreed to the same wavelength. The left image is obtained with a flat DM surface, the central one is obtained after 5 Phase Diversity iterations. We improved the correction by eliminating the ghost produced by the IR camera filter (lower left corner) and modifying the Phase Diversity technique by using closed loop images. The final results (image on the right) is an outstanding Strehl of 95%.


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25-Nov-2003: MAD Bench Installed in the Optical Lab
The MAD bench and its supporting structure have been installed in the ESO optical laboratory. This is a crucial milestone for the MAD project which represtents the beginning of the integration phase. Thanks are due to J.L.Lizon and S.Tordo for the great job.

The MAD bench during installation	The MAD bench installed at the ESO optical lab

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