Abstract: In a digital weather radar display, of the type which displays information on a cathode ray tube in the form of parallel intensity modulated sweep lines and which displays range marks in the form of a plurality of arcs of concentric circles, the positions of the range marks along each of the sweep lines are determined by utilizing a read only memory which stores, for each sweep line, an indication of the distance between range marks and the distance from the beginning of scan of the line to the first range mark.

Abstract: A frame of information to be displayed in the form of a row and column matrix of display elements is created from a corresponding group of data cells stored functionally in the form of a row and column matrix where the number of rows and columns in the stored matrix is less than the number of rows and columns in the displayed matrix. The value of each display element is determined by obtaining the average of the values of the data cells with which the display elements immediately adjacent the display element, the value of which is to be determined, correspond summed with n times the value of the data cell corresponding to the display element, the value of which is to be determined, where n is an integer greater than one.

Abstract: The periods of several successive cycles of an alternating signal are determined and used to calculate the value corresponding to the statistical variance thereof. The deviation value is compared with a preselected value corresponding to the maximum variance expected of an alternating signal with a substantially uniform period. If the preselected value exceeds the computed value, an alternating signal with a uniform period is present while if the computed value exceeds the preselected value an alternating signal with a non-uniform period is present.

Abstract: A clutter immune radar where the interrogating unit transmits a modulated interrogation signal to a remote unit, which radiates an information-bearing reply signal, in order to enable the interrogating unit to obtain remote unit information and range by the use of three bandpass filter channels where one bandpass filter bandwidth is equal to the sum of the other two bandwidths.

Abstract: A frequency-modulated continuous wave (FM-CW) ranging system includes apparatus which utilizes a target simulating delay line and scaling device to compensate for undesired changes of the FM modulation waveform.

Abstract: A memory for a coordinate converter stores, for each azimuth at which information from an information source may be received in a polar coordinate system, the incremental X and Y coordinate values, .DELTA.X and .DELTA.Y, for an incremental change in range along the azimuth. For each azimuth these incremental coordinate values .DELTA.X and .DELTA.Y are retrieved from memory and entered into summing devices which are incremented respectively by .DELTA.X and .DELTA.Y for each increment of range. The integers of the values of the summing devices represent X and Y coordinate values in a rectangular coordinate system and may be utilized to address an information reception device such as a random access memory.

Abstract: An electronic mail box includes an entry slot for receiving a letter to be transmitted electronically to a remote point, an optical reader for converting the letter text to electronic signals, and a keyboard for receiving the address of the addressee. The address is checked for consistency. Then the text and the address are sent to the destination as determined by the address, where the letter is recreated to be delivered in the conventional manner.

Abstract: An electrode assembly is formed of two opposed groups of concentric selectively addressable electrodes positioned opposite a record medium. The electrode assembly is first positioned relative to the medium to produce thereon an incomplete image from an electrode of one group. Thereafter the electrode assembly is moved to a second position relative to the medium to produce the remaining portion of the selected image creating one closed image.

Abstract: An analog-to-digital converter includes a common input amplifying device such as a transistor in differential amplifier relationship with each of a plurality of output amplifying devices, one for each voltage range converted to digital form.Separately controllable circuits are provided for: (A) setting a video display screen signal to the threshold of visibility, and (B) increasing the brightness of the screen to various levels above the threshold in accordance with digital signals from the analog-to-digital converter as modified by a brightness control.

Abstract: A signal processor for monotonic FM-CW ranging system having reduced quantization error. The difference signal from FM-CW radar is applied to two cascaded phase locked loops (PLL). The second PLL is modified for unidirectional frequency tracking.

Abstract: A beam of light angularly directed relative to a surface of an object having a dimension to be measured is intercepted by the object, which is moving at a known speed. By knowing the beam angle, the object speed, and the time lapse between the passage of the object past a reference point and the point of beam interception, the dimension of the object is readily determined.

Abstract: A method and apparatus are disclosed for electronically transmitting to a remote point unique data to be included in a document and for electronically transmitting from a second independent source an authenticating mark for the document. Where a plurality of documents, all containing common information, are being transmitted, the common information is transmitted only once. Equipment at the remote location prints the finished document(s) ready for delivery to the recipient(s).

Abstract: In a CRT display exhibiting a Rho-Theta format where certain of the lines would normally extend beyond the edges of the CRT screen, feedback signals from at least a deflection coil are used to terminate display lines at the edge of the screen and to initiate immediate retrace. Compensation is applied to at least a deflection voltage to compensate for display line bunching caused by unequal scan line times.

Abstract: A two-odometer heading sensor wherein an accumulator is incremented or decremented in response to detected increments of turn angle. Provisions are disclosed for avoiding errors due to spurious differences in the distance sensed by the respective odometers.

Abstract: A doppler speed sensor for a ground vehicle wherein errors due to perpendicular velocity and vehicle tilt relative to the ground surface are substantially eliminated by utilization of a first receiving antenna having a radiation pattern disposed facing forwardly and covering a portion of the ground surface, and a second receiving antenna having a radiation pattern disposed facing rearwardly and overlapping the first antenna radiation pattern on the ground surface portion.

Abstract: Equipment operating at high voltage which is subject to damaging voltage breakdown at relatively high altitudes and therefore relatively low pressures has a pressure sensitive switch such as a spark gap included in the high voltage circuit in shunting relationship. At lower altitudes no voltage breakdown occurs across the spark gap and the high voltage circuit operates normally.At high altitude voltage breakdown occurs across the spark gap shunting potentially harmful voltages from the high voltage equipment.

Abstract: An aircraft DME is receptive of a series of pulses the nature of which alternates between a series of random time spaced pulses and a series of uniform time spaced pulses, where the latter serve to identify the source of the pulses. A set-reset type of counter triggered by the decoded series of random pulses or by the decoded series of uniform time spaced pulses is thereafter continually advanced to a known count producing a gate signal which searches and locks onto the decoded series of uniform time spaced pulses by repeating the process. After a preselected number of repeats corresponding to successive uniformly spaced pulses, audio signals are produced so long as the uniform spaced pulses continue.

Abstract: Contour correction circuitry is provided for use in a weather radar which has iso-contour circuitry and which has a digital display having a tendency to undesirably not display the trailing edge boundary, for example, of a storm cloud. The correction circuitry is responsive to even a momentary signal indicating the close of a contour for forcing a contour boundary to appear on the digital display. The correction circuitry also enhances the texture of the radar when displaying snow flurries, ground returns, etc. which exhibit unique pattern characteristics.

Abstract: Signals producing each spot in a digital two-dimensional spot matrix display, such as in a digital weather radar, are compared on a spot-by-spot basis with signals for immediately proceeding and following spots in each dimension. When the preceding and following spots have the same value, the spot being compared is caused to have that same value when displayed. The comparing circuitry may be provided signals from a radar antenna which receives, serially, signals at succeeding range points at a given azimuth and then at the same range points at succeeding azimuths. Signals at each given range at a plurality of succeeding azimuths may be averaged to produce an improved visual display. The compared signals may be further smoothed by averaging signals for succeeding azimuths and displaying the averaged signals alternating with the unaveraged signals.

Abstract: A machine readable binary encoded label having start, data, and stop sections comprising concentric arcuate or linear bars of two different reflectivities.The annular portions or bars are arranged into a coded array such that no more than four adjacent bars are of the same reflectivity type. The start and stop portions are arranged to provide to a scanner sufficient information to determine the scan rate of the scanner regardless of the rate of scan or dimension of bars merely by the scanning passage over the stop or start portion. Scanning circuits for transmitting data information from the data portion of the label to suitable data processing facilities includes a logic arrangement that automatically synchronizes the scanning circuit to the scanner device which may be a machine operating at a substantially constant scan rate or a hand-held wand operated within a wide range of scan rates.This is a division of application Ser. No. 345,322, filed Mar. 27, 1973.