RECEIVERS FOR PROCESSING DATA AND SIGNALS COMING FROM ARTIFICIAL SATELLITES IN THE FIELDS OF NAVIGATION, TOPOGRAPHY, GEODESY; EQUIPMENT FOR MEASURING AND RECORDING FREQUENCY AND TIME; ALARMS; RADIO NAVIGATION EQUIPMENT; TRANSMITTERS, RECEIVERS, TRANSMITTERS-RECEIVERS- TRANSMITTERS FOR RADIO NAVIGATION, RADIO LOCALIZATION, AMBIGUITY SURVEYING, MAKING CORRECTIONS; EQUIPMENT FOR PROCESSING AND VISUALIZING RADIO NAVIGATION; RADIO LOCALIZATION RECEIVERS; ELECTRONIC CIRCUITS WITH ELECTRO-MAGNETIC O...