Communications

Optical communications in terrestrial and space environments require transmitted signals on the order of 40 GHz and higher, because of the uncertain and changing transmission environments. A robust communications system is needed that will provide these frequencies and substantial discrimination between...

The TRMM (Tropical Rainfall Measuring Mission) and Terra ESMO (Earth Science Mission Operations) Ground Systems needed a method of passing scheduling data through the Goddard Mission Services Evolution Center (GMSEC) bus to other subsystems without modifying the Planning and...

The Integrated Trending and Plotting System (ITPS) is a comprehensive tool for storage, extraction, analysis, and plots of spacecraft housekeeping telemetry data (GMSEC R3.0 — Goddard Mission Services Evolution Center). ITPS reports information to...

An aircraft pilot would prefer to receive information on weather patterns, obstructions, and other conditions that may interfere with a flight plan, formal or informal, as the pilot’s flight proceeds, with a latency of no more than a few minutes. Learning of, and reacting to, a changing environment...

Silicon avalanche photodiodes (Si APDs) have low dark current and low excess noise factor, and are currently used in many of NASA’s missions. Noise equivalent power (NEP) of 40 to 50 fW/(Hz)1/2 over 140-MHz bandwidth has been demonstrated for Si APDs. Si APDs have very...

The conventional methods of improving wireless system coverage performance are to increase the transmitter power and/or antenna gain. The high transmit power could lead to more power consumption and RF exposure issues. The use of a high-gain antenna could lead...

In communications systems, there must be a method to identify the beginning of a message at the receiving end, to know when the data stream of a specified structure begins. This is conventionally done by inserting attached sync markers (ASMs) between codewords, and looking for these ASMs in the...

For effective range safety, global positioning system (GPS) metric tracking must be robust to interference with, and jamming of, GPS signals. The conventional approach to mitigating interference and jamming is to use a Controlled Reception Pattern Antenna (CRPA)....

An integrated communications and control system for unmanned aircraft systems (UAS) utilizes automatic dependent surveillance broadcast (ADS-B) technology. The prime objective of this system is to address safety concerns related to UAS sharing airspace with...

Bandwidth and power-coded modulation schemes are very desirable for many applications in high-data-rate transmission over a given allocated bandwidth. The goal is to design such coded modulation system for a given throughput with the lowest possible signal-to-noise ratio for not only a channel...

LDSD (Low Density Supersonic Decelerator) is a Mars EDL (entry, descent, and landing) Technology Development Project that launches three test vehicles out of the Pacific Missile Range Facility in Kauai. On the test vehicle, most mission science data can be recorded safely on land;...

This software is an implementation of the Licklider Transmission Protocol (LTP), a communications protocol intended to support the Bundle Protocol in Delay-Tolerant Network (DTN) operations. LTP is designed to provide retransmission- based reliability over links characterized by extremely long message...

This oscillator uses a single-emitter 0.3-μm InP heterojunction bipolar transistor (HBT) device with maximum frequency of oscillation (fmax) greater than 500 GHz. Due to high conductor and substrate losses at submillimeter-wave frequencies, a primary challenge is to efficiently use the...

A prototype wireless data-acquisition system has been developed as a potential replacement for a wired data-acquisition system heretofore used in testing rocket engines. The traditional use of wires to connect sensors, signal-conditioning circuits, and data acquisition circuitry is...

A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet...

A report describes the Orbiter Interface Unit (OIU) and the Early Communication System (ECOMM), which are systems of electronic hardware and software that serve as the primary communication links for the International Space Station (ISS). When a space shuttle is at or near the ISS during...