Fuzzy astronomical seeing nowcasts with a dynamical and recurrent connectionist network
نویسندگان
چکیده
We assess a neural-based method for fuzzy astronomical seeing prediction, based on known meteorological variables at the same time-point. This multiple regression, termed nowcasting 10, 11], will allow the modern telescopes to be preset, a few hours in advance, in the most suited instrumental mode. The data used are extensive meteorological and seeing measurements partly made at Cerro Paranal in Chile, site of the Very Large Telecope (VLT). A fuzzy correspondence analysis is carried out to explore the internal relationships in the data. Then, a time-and space-recurrent network is used in combination with a fuzzy coding approach to capture the temporal regularities of the seeing series. Such a connectionist network is endowed with an internal dynamic by means of arbitrary recurrent time-delayed connections. The performance of the model is appraised and the results are compared with the fuzzy k-nearest neighbors method.
منابع مشابه
Dynamical recurrent neural networks -- towards environmental time series prediction
Dynamical Recurrent Neural Networks (DRNN) (Aussem 1995a) are a class of fully recurrent networks obtained by modeling synapses as autoregressive filters. By virtue of their internal dynamic, these networks approximate the underlying law governing the time series by a system of nonlinear difference equations of internal variables. They therefore provide history-sensitive forecasts without havin...
متن کاملNowcasting Astronomical Seeing: Towards an Operational Approach
InMurtagh and Sarazin (1993), the ability to regress seeing on a set of near-ground meteorological variables was assessed. The present article proceeds towards the following operational framework: we obtain median seeing estimates for the night, given knowledge of ambient ground meteorological conditions. The data used are extensive meteorological and seeing measurements made at European Southe...
متن کاملDynamical Recurrent Neural Networks and Pattern Recognition Methods for Time Series Prediction: Application to Seeing and Temperature Forecasting in the Context of ESO's VLT Astronomical Weather Station
The European Southern Observatory's planned Astronomical Weather Station for the Very Large Telescope which is currently under construction at Cerro Paranal in Chile includes (i) advance temperature prediction, which would permit air conditioning in the telescope enclosure to be preset as a function of the next night's expected temperature; and (ii) prediction of seeing, a few hours in advance,...
متن کاملThe Prediction of Seeing and Other Relevant Climatological Conditions
The aim of exible scheduling is to improve the quality of observations and to guarantee eecient use of telescope time. Flexible scheduling implies the necessity of accurate forecasts and nowcasts (the latter term, widely used in aviation, implies near real-time analysis). The Astronomical Site Monitor (ASM) will constitute an interface between the VLT observer and the local environment. Seeing ...
متن کاملIdentification and control of dynamic systems using recurrent fuzzy neural networks
This paper proposes a recurrent fuzzy neural network (RFNN) structure for identifying and controlling nonlinear dynamic systems. The RFNN is inherently a recurrent multilayered connectionist network for realizing fuzzy inference using dynamic fuzzy rules. Temporal relations are embedded in the network by adding feedback connections in the second layer of the fuzzy neural network (FNN). The RFNN...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Neurocomputing
دوره 13 شماره
صفحات -
تاریخ انتشار 1996