Identification and recognition performance for four staring and two sc¿nning thermal imagers, \ryere measured in an observer experiment using images lhai were collected during a NATO freld trial in Nettuno, Italy, in 1998. The dataset allows validation of the MRTD and altemative sensor performance measures such as the TODI'2 (Triangle orientation Discrimination threshold). T\e 75%o correct Target Acquisition (TA) râñges were compared with the TOD sensor acuity and the MRTD spatial frequency at ÂT = 2 K. range and TOD sensor acuity (whicir is the equivaíent to the cycl ensor tJPe used' which means that the TOD is a good predicior TA range and MRTD spatial frequency, which is-the primary assunption for many lV ' Not only do sarrpling and starinj systðms have differãnt ratiãs, it also occurs that TA performance for staring systems depends on the internal noise of the sensor, u/hile rânge predictions based on the MRTD are determined solely by the resolution of the sampling array. In conclusion, a single 1Aãeruiontess) factor suffices to predict TA field performance from TOD sensor acuity for both staring and scanning ,yri"ms, while MRTù-based models fail to predict TA ranges, in particular for staring systems' This result in fact fufher validates the TOD as a tool for electro-optical imager performance characterization.

No abstract

Given data gr spee( choice This can be done using a real-time muttispectral 3CCD car¡treta, which records a scene with tluee detectors, each accuratcly set to a wavelength by selected opticat filt€rs. This leads to the subject of this papen how ûo rlect tåree optim¡t bards ¡p' hpcrspectrat data to perform a ccrtain task The choice of thesc bands inch¡der lwo aspects, the center wavetengtb, and thc spectral width. A band-selection and band-broadening proccdure has been developed, based on søtistical pattcrn-dopition techniques.We will demonsEate orn proposed band selection algoritln, and present its classification results compared to red-grcer, blue and red-green-near-infrared data for a miliury vehicle in a natur¿l backgrormd a¡d fo¡ surface laid landmines in vegetation.

Results of over 300far JR and mid JR transmission measurements taken during several EOPACE (BO Propagation Assessment in Coastal Environments) intensive operational periods (lOP's) over the low-level 15 km transmission path across San Diego bay are presented. A thorough comparison with calculations obtained using simultaneously measured bulk meteorological parameters with the IR Boundary Layer Model (IRBLEM), illustrate the effects thatrefractance, aerosol extinction and molecular extinction can have on the transmission. Discrepancies between the transmission measurements and the model's predictions are identified and investigated by varying various model parameters, and looking at available measured aerosol size distributions and refraction measurements over the path. Comparison with the measured transmissions are reasonably good and show that the total transmission depends critically on all three effects, with the molecular transmittance depending upon the water vapour density and the characteristics of the JR source and detector, the aerosol transmittance upon the visibility (aerosol concentration), and the refractive effects on the stability of the marine boundary layer or the virtual potential air-sea temperature difference.

During the False Bay trial (June 2007), the performance of a set of three optical sensors was tested against several small surface targets in a coastal area: a hyperspectral camera, a camera with a rotating polarization filter and a high resolution camera. One objective was the validation of a contrast and clutter model for the visual spectral band in this type of scenarios. Another issue was to test the benefit of using a polarisation filter and a hyperspectral unit in front of standard TV cameras. Finally the loss in identification capability of a high resolution camera at long range due to atmospheric blur was investigated. Data were collected of targets in near-sun direction at ranges up to seven kilometers, in all cases for down looking angles (targets below the horizon). Environmental parameters such as solar irradiance and windspeed were measured as input for the contrast and clutter models. Spatial, spectral and temporal effects of the target contrast and of the background clutter behaviour in the visual spectral band were determined as function of range and compared with model predictions. Samples of data and predictions are presented in this paper. The spatial and temporal target characteristics are of key importance for the development of algorithms for target detection, classification and tracking. Finally, rules of thumb, based on the measurements and model predictions, on the detection and identification range performances of specific optical sensors against small surface targets in a maritime environment are presented.