A filter spectrometer concept for facsimile cameras

A concept which utilizes interference filters and photodetector arrays to integrate spectrometry with the basic imagery function of a facsimile camera is described and analyzed. The analysis considers spectral resolution, instantaneous field of view, spectral range, and signal-to-noise ratio. Specific performance predictions for the Martian environment, the Viking facsimile camera design parameters, and a signal-to-noise ratio for each spectral band equal to or greater than 256 indicate the feasibility of obtaining a spectral resolution of 0.01 micrometers with an instantaneous field of view of about 0.1 deg in the 0.425 micrometers to 1.025 micrometers range using silicon photodetectors. A spectral resolution of 0.05 micrometers with an instantaneous field of view of about 0.6 deg in the 1.0 to 2.7 micrometers range using lead sulfide photodetectors is also feasible

An analysis of the facsimile-camera response to radiant point sources

In addition to imaging the surrounding terrain, planetary lander cameras may also be used to survey the stars to aid in locating the lander site. The response of the facsimile camera, which was selected for the Viking lander missions to Mars, to a radiant point source is formulated and shown to result in a statistical rather than deterministic signal. The signal statistics are derived and magnitudes are evaluated for the brighter visual and red stars. The probability of detecting the resultant statistical signals in photosensor and preamplifier noise and the associated probability of false alarms are also determined

Signal-to-noise ratio analysis and evaluation of the Hadamard imaging technique

The signal-to-noise ratio performance of the Hadamard imaging technique is analyzed and an experimental evaluation of a laboratory Hadamard imager is presented. A comparison between the performances of Hadamard and conventional imaging techniques shows that the Hadamard technique is superior only when the imaging objective lens is required to have an effective F (focus) number of about 2 or slower

Spectrometer integrated with a facsimile camera

This invention integrates a spectrometer capability with the basic imagery function of facsimile cameras without significantly increasing mechanical or optical complexity, or interfering with the imaging function. The invention consists of a group of photodetectors arranged in a linear array in the focal plane of the facsimile camera with a separate narrow band interference filter centered over each photodetector. The interference filter photodetector array is on a line in the focal plane of the facsimile camera along the direction of image motion due to the rotation of the facsimile camera's vertical mirror. As the image of the picture element of interest travels down the interference filter photodetector array, the photodetector outputs are synchronously selected and sampled to provide spectral information on the single picture element

Prediction of Viking lander camera image quality

Formulations are presented that permit prediction of image quality as a function of camera performance, surface radiance properties, and lighting and viewing geometry. Predictions made for a wide range of surface radiance properties reveal that image quality depends strongly on proper camera dynamic range command and on favorable lighting and viewing geometry. Proper camera dynamic range commands depend mostly on the surface albedo that will be encountered. Favorable lighting and viewing geometries depend mostly on lander orientation with respect to the diurnal sun path over the landing site, and tend to be independent of surface albedo and illumination scattering function. Side lighting with low sun elevation angles (10 to 30 deg) is generally favorable for imaging spatial details and slopes, whereas high sun elevation angles are favorable for measuring spectral reflectances

Modelling of critical power from road data

Background: Performance tests are an integral part of evaluating competitive cyclists. Despite all technological and physiological advances, limited research has been performed addressing the translation of standardized, relevant laboratory tests into the field and consequently into “real world” cycling (i.e. .(i.e. González-Haro et al., 2007: British Journal of Sports Medicine, 41(3), 174–179; Quod et al., 2010:InterInternational Journal of Sports Medicine, 31(6), 397–401; Nimmerichter et al., 2010: International Journal of Sports Medicine, 31(3), 160- 166). For continuous activities between approximately 2 and 30 minutes, the assessment of Critical Power (CP) is one such relevant test. Compromising ecological validity, to date CP testing is mostly constrained to the laboratory. Purpose: To investigate a novel CP road testing protocol. Methods: Laboratory determined CP values using a 30 min intra-trial recovery period (Bishop & Jenkins, 1995: European Journal of Applied Physiology and Occupational Physiology, 72 (1-2), 115-120) were compared with those determined in the field, i.e. on the road. The experiment comprised of planned maximal efforts of 12 min, 7 min and 3 min with a 30 min recovery period between efforts. Linear regression was used to determine CP using the work- Results: There was no significant difference between laboratory and road CP values. The mean difference between the two environments was 0 ± 5.5 W. The standard error of estimates was 1.7% and limits of agreement were -10.8 – 10.8 W (Fig. 1). Discussion: Results suggests that CP can be tested on the road. Gonzales-Haro accepted their incremental velodrome field test as being valid with reported limits of agreement of 130 W to – 24 W and a random error of 13.9%. Our limits of agreement values are considerably higher and standard error of estimate values are considerably lower than those reported by Gonzales-Haro. The experimental protocol provides a practical and easy to use alternative to the conventional testing protocol for coaches and athletes when determining CP in on the road. Conclusion: The aforementioned research provides support for the acceptance of road CP performance testing using a 30 min inter-maximal effort recovery period