Range ambiguity

Keywords SBR STAP earth rotation range ambiguity crab angle crab magnitude Doppler dispersion range dependency waveform diversity Doppler warping. 

Figure 12. Common wavefront showing all range ambiguity returns corresponding to a point of interest at range R.

Total Range Foldover. Radar transmits pulses every Tr seconds and for high PRF situations, following (24), the distance Ar between range ambiguities on the ground (distance between consecutive pulse... 

To compute the total number of range foldovers for the entire range, we can make use of Fig. 16. In Fig. 16, the point of interest (D) is within the mainbeam, and the return of the radar pulse from there represents the main clutter. However because of the 2-D antenna pattern, previous pulse returns returning from adjacent range ambiguities points — both... 

Figure 17. Number of range ambiguities as a function of SBR height and PRF.

To compute the immediate forward and backward range ambiguity points (E and F respectively), the geometry in Fig. 14 can be used. In general, the kth forward and backward range ambiguity points are given... 

Reasons for employing a low PRF are elimination of range ambiguities, lower data rates for data acquisition, easier power supply development, etc. Higher PRF is desired for Doppler sampling requirements and average power and number-of-pulses-integrated considerations. 

Oscillator phase noise is one of the major contributors to this effect. Figure 17.17 shows the phase noise that can be expected from oscillators at a variety of common radar bands. The spectral spreading shown, modified by sampling effects and range ambiguity effects, is a measure of the subclutter visibility that can be achieved. 

This example of high and low pressure also shows the ambiguities of these tenns in science. All these pressures are essentially constant in tenns of tire range of pressures encountered in nature. From negative pressures in solids under tension (e.g., on the wall of flask confining a fluid), pressure in nature increases... 

Table 1 is condensed from Handbook 44. It Hsts the number of divisions allowed for each class, eg, a Class III scale must have between 100 and 1,200 divisions. Also, for each class it Hsts the acceptance tolerances appHcable to test load ranges expressed in divisions (d) for example, for test loads from 0 to 5,000 d, a Class II scale has an acceptance tolerance of 0.5 d. The least ambiguous way to specify the accuracy for an industrial or retail scale is to specify an accuracy class and the number of divisions, eg. Class III, 5,000 divisions. It must be noted that this is not the same as 1 part in 5,000, which is another method commonly used to specify accuracy eg, a Class III 5,000 d scale is allowed a tolerance which varies from 0.5 d at zero to 2.5 d at 5,000 divisions. CaHbration curves are typically plotted as in Figure 12, which shows a typical 5,000-division Class III scale. The error tunnel (stepped lines, top and bottom) is defined by the acceptance tolerances Hsted in Table 1. The three caHbration curves belong to the same scale tested at three different temperatures. Performance must remain within the error tunnel under the combined effect of nonlinearity, hysteresis, and temperature effect on span. Other specifications, including those for temperature effect on zero, nonrepeatabiHty, shift error, and creep may be found in Handbook 44 (5). The acceptance tolerances in Table 1 apply to new or reconditioned equipment tested within 30 days of being put into service. After that, maintenance tolerances apply they ate twice the values Hsted in Table 1.

Detection limits in ICPMS depend on several factors. Dilution of the sample has a lai e effect. The amount of sample that may be in solution is governed by suppression effects and tolerable levels of dissolved solids. The response curve of the mass spectrometer has a large effect. A typical response curve for an ICPMS instrument shows much greater sensitivity for elements in the middle of the mass range (around 120 amu). Isotopic distribution is an important factor. Elements with more abundant isotopes at useful masses for analysis show lower detection limits. Other factors that affect detection limits include interference (i.e., ambiguity in identification that arises because an elemental isotope has the same mass as a compound molecules that may be present in the system) and ionization potentials. Elements that are not efficiently ionized, such as arsenic, suffer from poorer detection limits. 

In view of the possible ambiguities which can attend conformational assignments based on vicinal coupling constants, it is fortunate that both long-range and geminal couplings each exhibit stereospecific dependences. 

The reason for that ambiguity is the fact that the l/V characteristics are Fitted with equations (see above) consisting of various fit parameters in a rather restricted voltage range, so that many different curves can model the l/V curves within a moderate variance range. 

Appreciable deviations from the assumed simple model with constant Ed and kd throughout a significant desorption range evidently impair the estimate of the desorption order and may make its value quite ambiguous. 

The term particle and particle size are so highly ambiguous as to require precise definition. As used in this article particles will.be limited by size to those distinct entities which have physically detectable boundaries in any direction within the limits of 0.05 and 10 microns (1 micron, p -0.001mm). This size range covers those particles which can be directly measured without magnification down to those which exhibit colloidal behavior... 

Although this particular analysis is of value in the systematic theoretical consideration of the consequences of nucleation and growth reactions, the complicated expressions which result have found few applications in recent work. In the original development [454], ranges of application were shown to be of limited extent, involving initial and/or final deviations, and ambiguities of interpretation [28] reduced the precision, and therefore the value, of the mechanistic conclusions derived from this kinetic approach. 

Vitamins such as thiamin, biotin, and vitamin Bj2 are often added. Once again, the requirements of anaerobes are somewhat greater, and a more extensive range of vitamins that includes pantothenate, folate, and nicotinate is generally employed. In some cases, additions of low concentrations of peptones, yeast extract, casamino acids or rumen fluid may be used, though in higher concentrations, metabolic ambiguities may be introduced since these compounds may serve as additional carbon sources. 

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