Rotational Distortion Research Articles

New analysis of line positions of the ν3 bands of 35ClNO2 and 37ClNO2 around 370 cm−1

A new investigation of the ν3 bands of 35ClNO2 and37ClNO2, located around 370 cm−1 has been performed using a high resolution (0.00102 cm−1) Fourier transform spectrum recorded at SOLEIL with highly improved experimental conditions as compared to previous work [Orphal J, Morillon-Chapey M, Klee S, Mellau GC, Winnewisser M. J Mol Spectrosc 1998;190:101–6]: (i) the use of synchrotron radiation which resulted in a better signal-to-noise ratio; (ii) a resolution twice better; (iii) a low temperature (221 K) with an optical path length of 8.16 m, allowing low pressure (0.025 hPa) in the sample leading to a well resolved spectrum. As a consequence, significantly better results than previously were obtained. Thanks to the new experimental conditions, the line assignments were pursued up to higher J and Ka quantum number values, J = 83 and Ka = 44. For both isotopomers, a total of 6331 transitions were reproduced with a root-mean-square deviation of 2 × 10−4 cm−1 using a Watson-type A-reduced Hamiltonian. Improved rotational and centrifugal distortion constants for the ν3 fundamental bands of 35ClNO2 and37ClNO2 have been determined. The band centers are 370.1510773(92) cm−1 for the ν3 fundamental band of 35ClNO2 and 364.5218094(96) cm−1 for the ν3 fundamental band of 37ClNO2. The synthetic line list obtained in this study could be interesting for future measurements of ClNO2 in the atmosphere, e.g. using the new space mission FORUM which is one of the concepts chosen by ESA to be developed further and which opens up a new window (150–1400 cm−1) for understanding and quantifying the radiative processes, as well as air quality and pollution effects.

Vibrational properties of LaNiO3 films in the ultrathin regime

Collective rotations and tilts of oxygen polyhedra play a crucial role in the physical properties of complex oxides such as magnetism and conductivity. Such rotations can be tuned by preparing thin films in which dimensionality, strain, and interface effects come into play. However, little is known of the tilt and rotational distortions in films a few unit cells thick including the question of if coherent tilt patterns survive at all in this ultrathin limit. Here, a series of films of perovskite LaNiO3 is studied and it is shown that the phonon mode related to oxygen octahedral tilts can be followed by Raman spectroscopy down to a film thickness of three pseudocubic perovskite unit cells (∼1.2 nm). To push the limits of resolution to the ultrathin regime, a statistical analysis method is introduced to separate the Raman signals of the film and substrate. Most interestingly, these analyses reveal a pronounced hardening of the tilt vibrational mode in the thinnest films. A comparison between the experimental results, first principles simulations of the atomic structure, and the standing wave model, which accounts for size effects on the phononic properties, reveals that in the ultrathin regime, the Raman spectra are a hybrid entity of both the bulk and surface phononic behavior. These results showcase Raman spectroscopy as a powerful tool to probe the behavior of perovskite films down to the ultrathin limit.

Portrayal Matching Algorithm By using Sift

Image identification and matching is one of the very difficult assignment in different areas of mainframe view. Scale-Invariant Feature Transform is an algorithm to perceive and represent specific features in portryals to further use them as an image matching criteria. In this paper, the extracted SIFT matching features are against various image distortions such as rotation, scaling, fisheye and motion distortion are evaluated and false and true positive rates for a large number of image pairs are calculated and presented.

A Multilayer Fusion Network With Rotation- Invariant and Dynamic Feature Representation for Multiview Low-Altitude Image Registration

Due to human and natural factors, when the small unmanned aerial vehicles (UAVs) are monitoring the ground, multiview transformation problems such as image distortion and low overlap will occur, which will inhibit the accuracy of low-altitude image registration and limit the subsequent application. In this letter, we propose a mismatch removal method based on the Siamese architecture to solve the issues of multiview images. A dynamic neighbor-guided patch representation is designed to enhance the representation of each feature point. Meanwhile, a multilayer fusion is used to obtain more comprehensive information on feature points, and whether a pair of points correspond depends on the similarity of its descriptors. The network is trained by adding a rotation-invariant layer to solve the inevitable rotation and image distortion in multiview scenarios. The experimental results prove that our method can deal with the scenarios of the horizontal rotation, vertical rotation, mixture, scaling, and extreme, and is better than the other five state-of-the-art methods in most scenarios.

Anomalous absorption of hydrogen peroxide (H2O2) rotational transitions

Hydrogen peroxide (H2O2) is considered to play important role in the chemistry of ozone layer in the troposphere. It also has been detected first time in the cold environment of a star-forming region towards ρ Oph A. According to the selection rules for dipole allowed transitions, the H2O2 ro-torsional levels may be classified into four distinct groups. Using the spectroscopic information (rotational and centrifugal distortion constants, and electric dipole moment), we have calculated energies of lower 50 levels of each group, and radiative transition probabilities for transitions between the levels. Using these radiative transition probabilities along with the collisional rate coefficients (obtained with the help of a scaling law), we have solved, for each group, a set of 50 statistical equilibrium equations coupled with the equations of radiative transfer and have found 16 lines showing anomalous absorption. In addition to four astronomically detected lines, 24 lines are found to show emission features. All these lines may play a significant role for the identification of H2O2 in the interstellar medium.

FIR spectroscopy and DFT calculations involving 2-chloroethanol: Analysis of the ν19 + ν21←ν21 torsional hot band, and the solvated substitution reaction between ethylene glycol and hydrogen chloride

We build upon a recent investigation of 2-chloroethanol (2CE) which focused on its high-resolution far-infrared (FIR) spectroscopy, and ab initio calculations that considered potential synthetic routes leading to its formation in interstellar molecular clouds. Here we report a rovibrational analysis of the normal isotopologue of 2CE (35ClCH2CH2OH) in the ν19 + ν21 – ν21 hot band (at ∼340 cm−1), that is complimented by density functional theory (DFT) calculations on the substitution reaction between hydrogen chloride and ethylene glycol in the presence of a simulated water environment. The spectroscopic analysis presented here involves the assignment of 2065 lines (J ≤ 79), and determination of rotational and centrifugal distortion constants up to sextic level using Watson’s A-reduction Hamiltonian. The calculations show that the reaction leading to 2CE proceeds in a qualitatively different way in a water-like environment in comparison to the gas phase, with a much broader barrier that is significantly lowered, and an early dissociation of HCl to give protonated ethylene glycol in the entrance channel.

Microwave Spectra and Theoretical Calculations for Two Structural Isomers of Methylmanganese Pentacarbonyl.

The first microwave rotational spectra for two structural isomers of methylmanganese pentacarbonyl were measured in the 4-9 GHz range using a pulsed-beam Fourier transform microwave spectrometer. The spectra for the two isomers, a symmetric-top structure and an asymmetric-top acyl isomeric structure, were fit to obtain rotational and centrifugal distortion constants and 55Mn quadrupole coupling parameters. The rotational constants, the manganese (55Mn) nuclear quadrupole coupling constant, the centrifugal distortion constants, and the spin-rotation constant were determined for the symmetric CH3Mn(CO)5 and have the following values: A = B = 793.153(3) MHz, DJ = 0.00040(4) MHz, DJK = 0.0018(2) MHz, Ccc = 0.183(6) MHz, and eQqcc= -87.4(3) MHz. Rotational constants and 55Mn quadruple coupling constants were determined for the isomeric acyl-CH3C(O)Mn(CO)4 and have the following values: A = 839.96(4) MHz, B = 774.20(7) MHz, C = 625.63(1) MHz, and 1.5 eQqaa= 44.9(47) MHz and 0.25(eQqbb - eQqcc) = 11.9(12) MHz. The measured rotational constants from the isomeric acyl-CH3C(O)Mn(CO)4 were compared with various theoretical computations. The calculated rotational constants for the dihapto-acyl and the agostic-acyl structures are reasonably close to the experimental values. We note that the calculated dihapto-acyl structure most closely matches the experimental data, as the calculation for the dihapto structure using the B3LYP functional with the aug-cc-pVDZ basis set closely reproduced the experimental values for A, B, and C.

Rotational spectra in seven excited vibrational states of 1,2,3,4-tetrahydroquinoline

In this study, more than 7000 rotational line frequencies in vibrationally excited states (ν57, ν56, 2ν57, ν57 + ν56, ν55, 3ν57, ν54) of 1,2,3,4-tetrahydroquinoline (THQ) were measured, assigned and analyzed. The line assignments were facilitated by the Loomis-Wood, Fortrat and other specific diagrams. The rotational transition frequencies were least-squares fitted to sextic A-reduced Hamiltonians. Based on the analyses, the rotational and centrifugal distortion constants of the above-mentioned excited vibrational states were determined with very high accuracies.

Theoretical exploration of mixed-anion antiperovskite semiconductors M3XN(M=Mg,Ca,Sr,Ba;X=P,As,Sb,Bi)

Antiperovskites have recently been attracting considerable attention because of their intriguing physical properties. We theoretically investigate polymorphism of mixed-anion antiperovskites ${M}_{3}^{2+}{X}^{3\ensuremath{-}}{\mathrm{N}}^{3\ensuremath{-}}\phantom{\rule{4pt}{0ex}}(M$ = Mg, Ca, Sr, Ba; $X$ = P, As, Sb, Bi) using the seven representative crystal-structure prototypes of $AB{Z}_{3}$ compounds. Stable crystal-structure exploration for four unreported compounds $({\mathrm{Mg}}_{3}\mathrm{PN},{\mathrm{Sr}}_{3}\mathrm{PN},{\mathrm{Ba}}_{3}\mathrm{PN}$, and ${\mathrm{Mg}}_{3}\mathrm{BiN})$ is also performed using ab initio evolutionary crystal-structure-search and lattice-dynamics calculations, which have consistently identified antiperovskite phases as their ground states. As a result of crystal-structure exploration, the orthorhombic perovskite $Pbnm$ phases of ${\mathrm{Mg}}_{3}\mathrm{PN},{\mathrm{Sr}}_{3}\mathrm{PN}$, and ${\mathrm{Ba}}_{3}\mathrm{PN}$ are obtained, while the cubic perovskite $Pm\overline{3}m$ phase is stable in ${\mathrm{Mg}}_{3}\mathrm{BiN}$. We show that the octahedral rotational distortions in ${M}_{3}\mathrm{PN}$ and ${M}_{3}\mathrm{AsN}$ reduce their Madelung energies, which is not common in conventional perovskites. Further, we estimate the ionic radii of anionic nitrogen ${\mathrm{N}}^{3\ensuremath{-}}$ and pnictogen ${X}^{3\ensuremath{-}}$ to explain the chemical trends for the phase stability, lattice distortion amplitude, total energies, valence bandwidths, and band gaps of ${M}_{3}X\mathrm{N}$ using the Goldschmidt tolerance factor. We also report the electronic structures of ${M}_{3}X\mathrm{N}$ with and without the rotational distortions and spin-orbit coupling. The valence bands of ${\mathrm{Mg}}_{3}X\mathrm{N}$ are created mainly from $p\text{\ensuremath{-}}p$ hybridization, whereas those of ${M}_{3}^{\ensuremath{'}}X\mathrm{N}\phantom{\rule{4pt}{0ex}}({M}^{\ensuremath{'}}$ = Ca, Sr, Ba) are constructed mainly from $d\text{\ensuremath{-}}p$ hybridization. We then explain the mechanism of the band-gap changes owing to the rotational distortions and spin-orbit coupling. The effective masses for the relevant ground-state phases of ${M}_{3}X\mathrm{N}$ are found to be comparable to preexisting compound semiconductors. Finally, we propose potential applications of earth-abundant semiconductors ${\mathrm{Mg}}_{3}\mathrm{PN}$ and ${\mathrm{Sr}}_{3}\mathrm{PN}$ as light absorbers and emitters utilizing their direct-type band structures and high optical absorption coefficients. The present study provides a clear picture and recipe for the understanding and design of mixed-anion antiperovskites.

Structure, Dynamics, and Accurate Laboratory Rotational Frequencies of the Acrylonitrile-Methanol Complex.

The hydrogen-bonded complex between acrylonitrile (CH2=CHCN) and methanol has been characterized spectroscopically in the millimeter wave range (59.6–74.4 GHz) using a free jet absorption millimeter wave spectrometer. Precise values of the rotational and centrifugal distortion constants were obtained from the measured frequencies of the complex of acrylonitrile with CH3OH and CD3OD. The analysis of the splittings of the rotational lines due to the hindered internal rotation of the methanol methyl group led to the determination of a V3 value of 221.9(7) and 218(5) cm–1 for the complexes of CH3OH and CD3OD, respectively, and these values are about 40% lower than that of free methanol. The structure of the observed conformation is in agreement with the global minimum determined at the MP2/aug-cc-pVTZ level of calculation, and the counterpoise corrected intermolecular binding energy, obtained at the same theoretical level, is De = 26.3 kJ mol–1.

Spectroscopic patch model for massive stars using PHOEBE II and FASTWIND

Context. Massive stars play an important role in the mechanical and chemical evolution of galaxies. Understanding the internal processes of these stars is vital to our understanding of their evolution and eventual end products. Deformations from spherical geometry are common for massive stars; however, the tools that are currently available for the study of these systems are almost exclusively one-dimensional. Aims. We present a new spectroscopic analysis tool tailored for massive stars that deviate from spherical symmetry. This code (entitled SPAMMS) is a spectroscopic patch model that takes the three-dimensional surface geometry of the system into account to produce spectral profiles at given phases and orientations. Methods. In using the Wilson–Devinney-like code PHOEBE in combination with the nonlocal thermodynamic equilibrium radiative transfer code FASTWIND, we created a three-dimensional mesh that represents the surface geometry of our system and we assigned FASTWIND emergent intensity line profiles to each mesh triangle, which take the local parameters such as temperature, surface gravity, and radius into account. These line profiles were then integrated across the visible surface, where their flux contribution and radial velocity are taken into account, thus returning a final line profile for the visible surface of the system at a given phase. Results. We demonstrate that SPAMMS can accurately reproduce the morphology of observed spectral line profiles for overcontact systems. Additionally, we show how line profiles of rapidly-rotating single stars differ when taking rotational distortion into account, and the effects that these can have on the determined parameters. Finally, we demonstrate the code’s ability to reproduce the Rossiter–Mclaughlin and Struve–Sahade effects.

Intramolecular hydrogen bond stabilized conformation of 3-aminopropanol

Rotational spectra of the most abundant, three 13C, and the 15N isotopologues of 3-aminopropanol have been recorded in natural abundance using a Fourier-transform microwave spectrometer. For the most abundant isotopologue, 54 hyperfine components from the thirteen a- and b-type transitions measured were fit to the quadupole coupling constants, χaa = −2.551(1) MHz, χbb = 1.248(1) MHz. Rotational and centrifugal distortion constants determined from fits of the resulting unsplit line centers to the Watson A-reduction Hamiltonian are A = 7405.303(1) MHz, B = 3868.1925(5) MHz, C = 2829.2615(7) MHz, ΔJ = 1.90(3) kHz, ΔJK = −0.5(3) kHz, ΔK = 2.7(3) kHz, δJ = 0.5(4) kHz, and δK = 4.0(4) kHz. Five to six transitions were measured for each of the 13C and 15N isotopologues and rotational constants were determined by fixing the distortion constants to the values found for the normal isotope. The five sets of moments of inertia were used to determine the 3-aminopropanol substitution structure as well to perform a least-squares fit. The heavy atom coordinates determined from these two methods are in good agreement. The newly measured moments of inertia of the heavy atoms has allowed for a refinement of the structure determined by an earlier microwave study. The conformation of 3-aminopropanol is stabilized by an intramolecular hydrogen bond from the alcohol proton to amino nitrogen. The experimental structure is consistent with the lowest energy ab initio [MP2/6-311++G(d,p)] structure.

Spectroscopy of a low global warming power refrigerant. Infrared and millimeter-wave spectra of trifluoroethene (HFO-1123) in the ground and some vibrational excited states

In the present work we carried out a combined rotational and ro-vibrational investigation on 1,1,2-trifluoroethene, a relevant unsaturated hydrofluoroolefin recently proposed as refrigerant in mixture with other halogenated compounds (like difluoromethane). By employing a frequency-modulation millimeter-wave spectrometer, the rotational spectra were recorded in the frequency ranges 80–96 GHz and 245–260 GHz for the ground and also the vibrationally excited states ν8=1,ν9=1,ν12=1,ν9=2,ν12=2, and ν9=ν12=1. In addition, the infrared spectra in the region of the ν6 band (centered at 929.8cm−1) were measured with a high-resolution Fourier transform spectrometer. The data coming from the detailed rotational and ro-vibrational assignments were combined in a global fit, taking into account also the ground state transitions available in the literature. From this analysis, a very accurate set of rotational and centrifugal distortion constants was determined for the ground state and for all the vibrationally excited states here investigated.

The rotation of α Oph investigated using polarimetry

ABSTRACT Recently we have demonstrated that high-precision polarization observations can detect the polarization resulting from the rotational distortion of a rapidly rotating B-type star. Here, we investigate the extension of this approach to an A-type star. Linear-polarization observations of α Oph (A5IV) have been obtained over wavelengths from 400 to 750 nm. They show the wavelength dependence expected for a rapidly rotating star combined with a contribution from interstellar polarization. We model the observations by fitting rotating-star polarization models and adding additional constraints including a measured vesin i. However, we cannot fully separate the effects of rotation rate and inclination, leaving a range of possible solutions. We determine a rotation rate (ω = Ω/Ωc) between 0.83 and 0.98 and an axial inclination i > 60°. The rotation-axis position angle is found to be 142 ± 4°, differing by 16° from a value obtained by interferometry. This might be due to precession of the rotation axis due to interaction with the binary companion. Other parameters resulting from the analysis include a polar temperature Tp = 8725 ± 175 K, polar gravity log gp = 3.93 ± 0.08 (dex cgs), and polar radius Rp = 2.52 ± 0.06 R⊙. Comparison with rotating-star evolutionary models indicates that α Oph is in the later half of its main-sequence evolution and must have had an initial ω of 0.8 or greater. The interstellar polarization has a maximum value at a wavelength (λmax) of 440 ± 110 nm, consistent with values found for other nearby stars.

New concept for art and antiquities identification based on craquelure pattern analysis

In this paper, it is shown that the craquelure patterns of paintings and other antiquities can be considered as fingerprints so that the authenticity of any given artwork can then be verified against prior works. The authors propose to extract craquelure features from photographic images and use them in the implementation of a unique matching procedure to address the art forgery issue as well as to monitor the health conditions of the objects concerned. This feature extraction strategy is robust against illumination, scale, rotation and perspective distortion. The craquelure extraction system developed, called multi-scale multi-orientation morphological processing (MMMP), performs analyses in each sub-band. A comprehensive craquelure image dataset has been constructed from a variety of different types of painting and other art objects. The results show significant improvement and compare favourably with the current best results in the market.

Profiling C4N radicals of astrophysical interest

ABSTRACT Based on a theoretical study of neutral, anion, and cation $\text{C}_{4}\text{N}$ chains, we suggest that this molecular species can still be observed in space. We analyse the dependence on n of the enthalpies of formation across the $\text{C}_{{{ n}}}\text{N}$ family and present possible chemical pathways of $\text{C}_{4}\text{N}$ production, which are not only exoenergetic but also barrierless. To further assist astronomical observation, we report estimates obtained at the CCSD(T) level of theory for astrophysically and astrochemically relevant properties. These include structural and chemical data, dipole moments, vibrational frequencies, rotational and centrifugal distortion constants as well as electron affinity, ionization potential, and related chemical reactivity indices. Our results indicate that anion chains can be easily detected in space than neutral chains; $\text{C}_{4}\text{N}^{-}$ possesses a smaller enthalpy of formation and a substantially larger dipole moment than $\text{C}_{4}\text{N}^{\text{0}}$.

DFT meets the segmented polarization consistent basis sets: Performances in the computation of molecular structures, rotational and vibrational spectroscopic properties

Quantum-chemical calculations assist the analysis of laboratory spectra, and often provide the only means to determine spectroscopic data that cannot be accessed experimentally. For the purpose, reliable predictions of structural and spectroscopic parameters are required. Although coupled cluster theory in conjunction with to large basis sets and composite schemes can reach impressive accuracies for structural, thermochemical and spectroscopic properties, it is still limited to small sized molecules. DFT represents the working option for medium to large molecular systems. In this context, systematic investigations are required aimed at characterizing the performances of the different DFT model chemistries. In this work, the accuracy of the popular hybrid B3LYP and the double hybrid B2PLYP functionals coupled to the segmented polarization consistent (aug-)pcs-n basis sets in the prediction of molecular structures and rotational- and vibrational spectroscopic parameters are investigated using a benchmark set of molecules of both atmospheric and astrochemical relevance. For comparison purposes, different flavors of Dunning’s triple-ζ basis sets and the SNSD basis set, are also employed. The convergence behavior of the pcs-n hierarchy with n = 1–4 is also addressed to some extent. The results indicate the B3LYP-D3 functional in conjunction with the aug-pcs-1 or SNSD basis sets as a cost-effective model chemistry for applications in the field of rotational and vibrational spectroscopies. Improved accuracy is obtained by coupling the B2PLYP-D3 functional with the aug-pcs-2 or aug-cc-pVTZ triple-ζ basis sets that show an accuracy around 0.003 Å and 0.3° for bond lengths and angles, 1% and 3% for rotational and quartic centrifugal distortion constants, respectively, 12 cm−1 for fundamental frequencies and 3 km mol−1 for IR intensities. The B2PLYP-D3/maug-cc-pVTZ-dH level keeps the same accuracy, with slightly larger deviations for intensities.

Interpreting the Equatorially Antisymmetric Gravitational Field of Saturn Measured by the Cassini Grand Finale

Abstract The equatorially antisymmetric gravitational field of Saturn, represented by the four gravitational coefficients J 3, J 5, J 7, and J 9, has been measured by the Cassini Grand Finale. Since the rotational distortion and the internal structure do not contribute to the asymmetric gravity field, the spectrum of the odd coefficients offers a direct window into the structure and amplitude of fluid motion in Saturn. We show that the observed cloud-top asymmetric winds extending into Saturn’s interior cannot produce the measured gravity field, suggesting that the cloud-top winds are confined within a thin weather layer and hence do not contribute to the observed gravity. We interpret the asymmetric gravitational field by searching for an a priori unknown zonal circulation taking place in the molecular envelope. We find that a zonal circulation confined in the 20,000 km thick molecular layer produces the coefficients J 3, J 5, J 7, J 9 in agreement with measurements. The depth of the circulation is consistent with that inferred from the equatorially symmetric gravitational field of Saturn.

Gravity and limb-darkening coefficients for compact stars: DA, DB, and DBA eclipsing white dwarfs

Context. The distribution of the specific intensity over the stellar disk is an essential tool for modeling the light curves in eclipsing binaries, planetary transits, and stellar diameters through interferometric techniques, line profiles in rotating stars, gravitational microlensing, etc. However, the available theoretical calculations are mostly restricted to stars on the main sequence or the giant branch, and very few calculations are available for compact stars. Aims. The main objective of the present work is to extend these investigations by computing the gravity and limb-darkening coefficients for white dwarf atmosphere models with hydrogen, helium, or mixed compositions (types DA, DB, and DBA). Methods. We computed gravity and limb-darkening coefficients for DA, DB, and DBA white dwarfs atmosphere models, covering the transmission curves of the Sloan, UBVRI, Kepler, TESS, and Gaia photometric systems. Specific calculations for the HiPERCAM instrument were also carried out. For all calculations of the limb-darkening coefficients we used the least-squares method. Concerning the effects of tidal and rotational distortions, we also computed for the first time the gravity-darkening coefficients y(λ) for white dwarfs using the same models of stellar atmospheres as in the case of limb-darkening. A more general differential equation was introduced to derive these quantities, including the partial derivative (∂ln Io(λ)/∂ln g)Teff. Results. Six laws were adopted to describe the specific intensity distribution: linear, quadratic, square root, logarithmic, power-2, and a more general one with four coefficients. The computations are presented for the chemical compositions log[H/He] = −10.0 (DB), −2.0 (DBA) and He/H = 0 (DA), with log g varying between 5.0 and 9.5 and effective temperatures between 3750 and 100 000 K. For effective temperatures higher than 40 000 K, the models were also computed adopting nonlocal thermal equilibirum (DA). The adopted mixing-length parameters are ML2/α = 0.8 (DA case) and 1.25 (DB and DBA). The results are presented in the form of 112 tables. Additional calculations, such as for other photometric systems and/or different values of log[H/He], log g, and Teff can be performed upon request.

Research on 2F Optical Correlator Based on Neural Network Filter for Recognizing Large-Angle Rotation Distortion Target

It is difficult for optical correlator to recognize the target with large rotation distortion by using existing filters. To solve this problem, a new neural network model is constructed based on the physical recognition process of planar integrated 2F optical correlator. The new optical filter is optimized by training the neural network. The planar integrated 2F optical correlator can output sharp correlation peaks by using the new filter to recognize targets with arbitrary rotation distortion. Compared with the traditional OTSDF filter, the average increase of correlation peak index is up to 1402.4%, while the recognition performance of distortion invariant is also better than the new NNCRF filter. The simulation and experimental results show that the optical filter designed in this paper can effectively solve the problem of weak recognition ability of optical correlator for rotating distortion targets, especially for large angle rotating distortion targets.