We have been investigating ways to restore images of objects obtained with a telescope under anisoplanatic atmospheric conditions. Anisoplanatic means that the point spread function due to atmospheric turbulence is position dependent. We began by looking at extended astronomical objects, such as craters on the moon but have turned our attention to extended objects on the earth’s surface imaged ...

This paper illustrates the challenges imposed by the atmospheric channel on the design of a terrestrial laser communication link. The power loss due to scattering effect is described using the Kim/Kruse scattering model while the effect and the penalty imposed by atmospheric turbulence is highlighted by considering the bit error rate (BER) of an OnOff Keying modulated link in an optical Poisson...

The atmospheric optical turbulence profile, the strength of the turbulence as a function of altitude above the ground, can be used to determine the seeing statistics of a particular site. This information is useful for optimizing the tomographic process in Adaptive Optics systems and for characterizing the performance. In this paper, we describe a method to estimate the atmospheric turbulence p...

The split-step Fourier (SSF) algorithm is applied to simulate the propagation of radio waves in an atmospheric duct. The refractive-index fluctuation in the ducts is assumed to follow a twodimensional Kolmogorov power spectrum, which is derived from its three-dimensional counterpart via the Wiener-Khinchin theorem. The measured profiles of temperature, humidity and wind speed in the Gulf area o...

We investigated the feasibility of using nulling interferometry techniques in the stratosphere to search for extra-solar planets. Studies have shown wavefront distortions from atmospheric turbulence to be too large to obtain clear ground-based images. Wavefront errors caused by atmospheric turbulence in the stratosphere are on the scale of 1 angstrom [4], however, the level of the wavefront err...

[1] The carbon and oxygen isotopes of CO2 and the oxygen isotopes of H2O are powerful tracers for constraining the dynamics of carbon uptake and water flux on land. The role of land biota in the atmospheric budgets of these isotopes has been extensively explored through the lens of leaf-scale observations. At the ecosystem scale, kinetic fractionation is associated with molecular and turbulent ...

The degree of image degradation due to atmospheric turbulence is particularly severe when imaging over long horizontal paths since the turbulence is strongest close to the ground. The most pronounced effects include image blurring and image dancing and in case of strong turbulence image distortion as well. To mitigate these effects a number of methods from the field of image processing have bee...

Lindborg et al. (2010) claim that the apparent spectrum power law E(k) ≈ k−3 on scales ≥ 600 km obtained with the help of commercial jetliner trajectory deviations (GASP and Mozaic databases) could not be brought into question (Lovejoy et al., 2009a), because this spectrum corresponds to “a well known theory of quasi-geostrophic turbulence developed by Charney (1971)”. Lindborg et al. (2010) al...

The wind farm layout program FLaP (Farm Layout Program) estimates the wind speed at any point in a wind farm and the power output of the turbines. The ambient flow conditions and the properties of the turbines and the farm are used as input. The core of the program is an axis-symmetric wake model, describing the wake behind one rotor. Here an approach based on the simplified Reynolds equation w...

Synthetic Aperture (SA) imaging, including holographic aperture ladar (HAL), synthetic aperture ladar (SAL), and combinations thereof; are promising solutions for long range imaging applications. One of the major difficulties with real-world SA imaging is coherently processing the image information in the presence of atmospheric turbulence. Differential SAL imaging was proposed and patented in ...