Abstract: A new and improved computing apparatus for determining aircraft altitude has a pressure transducer to sense atmospheric pressure at which the aircraft is located, and from this and a preset local ground level atmospheric pressure reading, actually solve a non-linear altitude-pressure equation. The computed altitude is used in conjunction with a time measurement to determine aircraft vertical rate. The computed altitude also specifies an address in a memory circuit, with the data stored at such address being the grey code which is transmitted to others for air traffic control purposes.

Abstract: The operation of a television system or photographic camera in concert with line or boundary indicators or monitors at a sporting contest are controlled. When the indicator detects an event of interest during the contest being monitored, such as an intrusion or the presence of an object along a line or boundary, a signal is sent to a video replay recorder, also known as an instant replay system, to continue recording for a predetermined interval and thereafter cease.An indicator or mark is also transmitted into the recording system on occurrence of the event of interest and is recorded along with the continuing event until recording ceases. After recording ceases, operators of the television system may then play back the recorded event into the television system. During the play back, the recorded indicator is also transmitted into the television system to appear on television screens and indicate the time of occurrence of the event of interest.