TRANSISTORIZED DIGITAL DATA SYSTEM MODEL 2B.
Abstract
The manual is provided to understand, operate and maintain the units comprising the Transistorized Digital Data System - Model (TDDS-IIB) which is a portion of the Satellite Receiving Station. Orbiting satellites transmit two radio frequencies, each of which is received by separate receivers at the Receiving Station. At the Receiving Station, each received frequency is heterodyned with a reference frequency to produce two different (Doppler) frequencies. These two doppler frequencies are then combined in a Refraction Correction Unit (RCU) where correction is made for ionospheric refraction effects. The vacuum doppler signal from the RCU is presented to the TDDS-IIB where the time required to receive a predetermined quantity of doppler cycles is measured (in microseconds). This time interval and the time of day (in seconds) at which the measurement was made is then visually displayed on a digital display unit, and recorded on punched paper tape (5-level teletype code). In addition, the TDDS-IIB is capable of receiving an external timing pulse and measuring the period to an accuracy of 0.1 millisecond that this pulse lags the occurrence of the previous integral second of the station clock.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1964
- Accession Number
- AD0822750
Entities
Organizations
- Johns Hopkins University