摘要:
A method of calculating ionospheric scintillation includes calculating a motion-corrected perturbation of a GNSS radio signal received by a monitoring device deployed in an oceanic environment. The method includes calculating the σφ using the high rate phase of the GNSS signal adjusted by removing the change in distance between the monitoring device and the GNSS satellite. The calculating the σo may further include passing the adjusted high rate phase through a high pass filter to remove a drift motion of the monitoring device. The method further includes calculating the S4 through calculating a tilt angle between the antenna of the monitoring device with the GNSS satellite and adjusting the antenna gain through known gain pattern of the antenna. The wave height of the oceanic environment may be calculated by detrending the antenna height to remove low frequency motion when a high rate position of the monitoring device is calculated.
摘要:
The invention relates to a method for the radiometric imaging of a surface of the Earth using a passive array antenna including elementary antennas (A(k)) arranged onboard at least one mobile satellite relative to the surface, including an allocation step (214) upon each analytic measurement of the measured electromagnetic field (E(k,t(i))), an index (k) for identifying the corresponding elementary antenna (A(k) and a precise sampling date (t(i)) corresponding to the measurement. The step comprises an image reconstruction step (224) from a spatio-temporal visibility function including a set of visibility coefficients, at least one visibility coefficient being equal to the correlation of two measurement vectors M(k,j), M(k', j') developed from electromagnetic field measurements and having different sampling indices (j, j').
摘要:
A system and method for detecting turbulence includes several mobile platforms, a mobile platform velocity sensor, and several electromagnetic energy transmitters and receivers. The receivers receive the energy transmitted by the transmitter(s) after it has traveled along a path subject to the turbulence. The receivers detect alterations of the energy caused by the turbulence and filter the alterations for effects of the mobile platform velocity (on which either a transmitter or receiver is located). Additionally, the system may create a three-dimensional model of the. In another preferred embodiment, the present invention provides a method of detecting turbulence using a mobile platform. The method includes receiving electromagnetic energy that has traveled along a path subject to the turbulence and determining the alteration to the energy caused by the turbulence. The alterations are filtered of the effects of the velocity of the mobile platform on which the receivers are preferably located.
摘要:
Radiomètre interférométrique embarqué sur un véhicule spatial destiné à l'imagerie d'une émission de rayonnement d'une scène cible (ED), comprenant: - une pluralité d'éléments récepteurs agencés sous forme d'un réseau bidimensionnel ou tridimensionnel (REA) ; - des premiers moyens de traitement du signal (SP1) pour calculer un ensemble bidimensionnel d'échantillons d'une fonction de visibilité par corrélation croisée par paire des signaux reçus par lesdits éléments récepteurs ; et - des seconds moyens de traitement du signal (SP2) pour reconstruire une image à partir desdits échantillons de ladite fonction de visibilité ;
caractérisé en ce qu'il comprend en outre des moyens (ROT) de rotation dudit réseau bidimensionnel ou tridimensionnel (REA) autour d'un axe de rotation (z) qui est sensiblement dirigé vers ladite scène cible (ED) ; et en ce que lesdits seconds moyens de traitement du signal (SP2) sont adaptés pour reconstruire ladite image à partir d'une pluralité d'ensembles bidimensionnels d'échantillons de ladite fonction de visibilité, correspondant à différentes positions angulaires dudit réseau bidimensionnel ou tridimensionnel (REA) d'éléments récepteurs.
摘要:
The invention relates to a process for the routine detection of oil pollution and icebergs at sea and as an aid to navigation for seaborne traffic where there is a risk of collisions between ships and where icebergs may be present.
摘要:
Apparatus for processing a sequence of samples of a received signal R reflected by a target surface and having a delay and a frequency shift relative to a reference signal D to obtain a delay Doppler map for the reflected signal, the apparatus comprising: a first correlation module (9) for obtaining a plurality of partial correlations z(n', k) between the sequence of samples x r (n) corresponding to the reflected signal R and a sequence of samples x d (n) corresponding to the reference signal D, across a set of delays, the first correlation module being configured to obtain a number of partial correlations z(n', k) of said plurality of partial correlation, providing one partial correlation sample for each delay, by obtaining a DFT of at least a first sequence of samples and a DFT of at least a second sequence of samples, the first sequence comprising at least one subsequence of samples of the reflected signal and the second sequence comprising at least one associated subsequence of samples of the reference signal, and to obtain an inverse DFT of a sequence of samples derived from at least said DFTs of the first and second sequences; a memory (10) for storing a plurality of sets of partial correlation samples, the samples of each set corresponding to the partial correlations for a different delay; and a second correlation module (11) for obtaining a DFT of the samples in each set to determine the correlation between the sequences of samples of the reflected and the reference signals across a plurality of frequency shifts at each delay of the set of delays.
摘要:
The invention concerns an ocean wind speed scatterometer for the use as core instrument of a satellite. The scatterometer measures the back scattering coefficient of the ocean from three different angles in the C-band in a 50 km grid. A long pulse linear frequency modulation scheme allows the utilization of a single 60 Watt solid state power amplifier. The linear frequency modulation allows after deramping a frequency domain processing but avoids the restrictions to measurement angle and swath width inherent to the Doppler type scatterometer.
摘要:
A system and method for detecting turbulence includes several mobile platforms, a mobile platform velocity sensor, and several electromagnetic energy transmitters and receivers. The receivers receive the energy transmitted by the transmitter(s) after it has traveled along a path subject to the turbulence. The receivers detect alterations of the energy caused by the turbulence and filter the alterations for effects of the mobile platform velocity (on which either a transmitter or receiver is located). Additionally, the system may create a three-dimensional model of the. In another preferred embodiment, the present invention provides a method of detecting turbulence using a mobile platform. The method includes receiving electromagnetic energy that has traveled along a path subject to the turbulence and determining the alteration to the energy caused by the turbulence. The alterations are filtered of the effects of the velocity of the mobile platform on which the receivers are preferably located.