Original processing
Re-processing
A new version of the MASS software, Turbina, is being developed by the team of Victor Kornilov at the Moscow University. It has a capablity of re-processing existing MASS data, using saved files: main [*.mass] and statistical moments [*.stm].
Re-processing is needed for correcting various errors, such as wrong setting of magnification or detector parameters, errors in the computer time setting, etc. Thus, data with such errors can be recovered.
Tests are underway to correct for the effect of scintillation saturation. The methods of such correction are described in this Report . An example of re-processing with saturation correction is shown below. The data were collected at Cerro Tololo with the TMT MASS-DIMM instrument. The same data are also discussed here .
Original processing |
Re-processing |
| |
|
The effect of saturation "moves" the restored profiles to lower altitudes, while the turbulence strength is over-estimated. The re-processing shows that, in fact, strong turbulence on that night was concentrated in a single layer near the tropopause. The estimated seeing in the free atmosphere is less after re-processing. Note that at the beginning of the night, when turbulence was not yet strong, re-processing makes almost no effect (no saturation).
At some moments, the free-atmosphere seeing estimated by MASS is still larger than the seeing measured simultaneously by DIMM (see the plot below), indicating that the correction for saturation was incomplete. It is also plausible that DIMM slightly under-estimated turbulence in the high atmosphere.
