Abstract: A method and apparatus for controlling uplink transmission power in a satellite communication system is disclosed. The satellite communication system includes a satellite and one or more earth stations, one of which serving as a control station. The satellite can receive uplink signals from any one of the earth stations and retransmits the uplink signals as downlink signals, along with a beacon signal. The control station measures the power of the downlink signals and the beacon signal received from the satellite, and also measures the noise power near the beacon signal. From these measurements, the control station determines an appropriate gain value of the power for uplink transmissions for each of the earth stations.

Abstract: A transducer apparatus utilizing fiber optics for data transmission is disclosed in which an output optical signal is encoded with information representative of a parameter being measured and the encoded optical signal transmitted to a remote measurement and control apparatus site for decoding. The transducer is adapted to receive an input optical signal, and converts the input optical signal into electrical energy to power a driver. An electrical drive signal, generated by the driver, has a selectively variable frequency representative of the parameter being measured. Using the electrical drive signal, the output optical signal is generated. The driver includes a variable frequency oscillator whose frequency of oscillation is dependent upon the parameter being measured.

Abstract: A transducer for optical data transmission is disclosed in which an optical signal is encoded with information representative of a parameter being measured and transmitted to a remote measurement and control apparatus site for decoding. An input optical signal is received by the transducer and separated into first and second portions. The first portion of the optical input signal is converted to electrical energy and is used to power the transducer. The second portion of the input optical signal is modulated in response to the measured parameter and the modulated signal transmitted back to the remote site.

Abstract: A sorting apparatus universally applicable to any article sorting task without the necessity of changing a background member for each article type is characterized by first and second optically imposed "backgrounds" against which light reflected from the same portion of each article passing within a predetermined viewed area as defined by an optical frame is detected. Photodetectors associated with each "background" are operative to generate first and second electrical signal representations of the reflected light detected against each background. An electrical signal representative of the portion of the viewed area occupied by the article and functionally related to the difference between first and second signal representations is used to scale one of the first or second signals to provide a signal representation of the full-frame percentage reflectivity of the article. Additionally, a nulling circuit is operative while the articles are passing through the viewer to provide drift compensation.

Abstract: An apparatus for sorting articles based upon the presence of defects on the surface thereof is characterized by a roller conveyor carrying a random array of articles in transverse channels defined between adjacent rollers. As the conveyor is advanced through a viewed area the articles are simultaneously rotated such that electrical images are formed of the portions of the surface of each article within a viewing zone defined in each channel during a given time frame. The viewing zones advance a predetermined distance through the viewed are in synchronization with the scanning of the electrical images. A characteristic signal for the portion of the electrical image corresponding to each article is developed and output to a processor. The processor generates a classification signal representative of the acceptability of each article based upon the percentage of total surface of area or number of defects on the surface each article.

Abstract: A sorting apparatus for sorting a stream of articles and for ejecting unacceptably classified articles therefrom is characterized by an ejector dwell controller operative to control the duration of operation of an ejector element in accordance with the length of the article being ejected. The ejector is initiated when a predetermined lead-point on an article classified as unacceptable enters into an ejection zone proximal to the ejector and continues until a predetermined cut-off point thereon enters the ejection zone. An ejecting force is thus directed toward the same predetermined portion of each article being ejected without regard to the location of the defect causing the unacceptable classification.

Abstract: A sorting apparatus for sorting articles randomly disposed in an article stream includes a viewer for viewing a predetermined area through which the article stream is passed and for generating an electrical characteristic signal functionally related to the presence of a physical characteristic of the article passing within the viewed area. The electrical characteristic signal is compared to a range of signal values representative of a foreign object. The amount of time during which the characteristic signal falls within the range of signal values during a reference time interval is measured and compared with a time reference standard. An article reject signal is generated if the characteristic signal falls within the predetermined range of signal values for an amount of time exceeding the predetermined time reference standard.

Abstract: A sorting apparatus wherein a plurality of first and second electrical color signals from a predetermined number of viewer elements is utilized to generate classification signals functionally related to the ratio of the color signals from each viewer and an ejector associated with each viewer is actuated if a comparison of each ratio classification signal with predetermined references indicates an unacceptably colored product or foreign object is characterized by a foreign object ejector arrangement being operable if the ratio classification signal falls within a predetermined defined range of signal values. A threshold network actuates the foreign object ejector arrangement only if an article is detected within the field of view of the viewer elements. Circuitry to present a substitute classification signal within the predetermined range of signal values if the electrical color signals are of equal value is provided.

Abstract: Apparatus for sorting articles is characterized by a nulling arrangement which corrects for amplifier offset and drift as the sort occurs. The nulling arrangement samples the amplifier output during a predetermined sample time period to detect the lowest signal output from the amplifier during the sample period. An electrical signal representative of the difference between the lowest detected signal and a predetermined reference signal representative of the light reflected from the background is generated for application as a correction signal to the amplifier. A memory stores the largest correction signal detected during the previous sample period for application to the amplifier during the present sample period. The memory also stores the largest correction signal detected during the present sample period.

Abstract: Apparatus for sorting articles is characterized by a circuit arrangement responsive to first and second electrical signals representative of the light reflected from the same portion of the article to be sorted as detected against a first and a second background, the first background having a reflectivity characteristic greater than the reflectivity characteristic of the second background, to generate an electrical signal representation of the portion of the viewing zone occupied by the article. This signal is used to scale both the first and second signals to provide an electrical signal representation of the reflectivity of the article at the first and second color wavelengths.

Abstract: A sorting apparatus wherein a plurality of first and second electrical color signals from a predetermined number of viewer elements are sampled by a time multiplexer, classified on the basis of the ratio of the color signals sampled from each viewer, and demultiplexed to actuate an ejector associated with each viewer if a comparison of the ratio classification signal with predetermined references indicates an unacceptably colored product or foreign object is characterized by circuitry for testing the digital logic elements associated with the sorting apparatus, and for sampling and displaying signal outputs from predetermined test points within the sorter circuitry at predetermined multiplex times.