The introduction of reliable, long-range radar systems during World War II represented a fundamental change in the nature of warfare. For the first time, it was possible for friendly forces to see the enemy from a distance without being detected— an incredible advantage. Naturally, the emergence of a new technological innovation motivated other parties to find ways to counter it, leading to the development of radar jamming and other deception technologies.
In this article, we will discuss jamming and deception in detail, and how innovations like the Next Generation Jammer are shaping the next chapter in the electronic warfare arms race.
When radar was first used in combat, it represented what is known as a “Revolution in Military Affairs” (RMA), a term used to describe a tactical, doctrinal, strategic, or in this case, technological change in military theory and activity that fundamentally changes the nature of warfare. World War II saw the first widespread use of radar on both sides of a conflict, and led to the emergence of electronic warfare as a method of counteracting the other side’s radar abilities while defending the friendly use of the electromagnetic spectrum. This competition spawned the evolution of many different radar functions for specialized applications. This article will explore various types of radar systems that exist and the functions they serve.
In Part 1 of our series on COTS components for space applications, we discussed why the government is increasingly turning to “commercial off the shelf” parts for spacecraft, satellites and more. COTS parts have already been successfully adopted in many military applications, but when it comes to space, COTS adoption has been much slower.
Space exploration has never been cheap. In the days of the Apollo program, the cost of sending payloads into space was such that only government agencies with billions of dollars to spend could afford it. Over time, those costs have begun to come down, but even with advances in launch technology, funding for such activities ebbs and flows. In the wake of budget cuts for military and aerospace Research and Development, there has been much pressure to develop systems and designs that meet the needs of space projects and reduce costs without sacrificing quality. This is where COTS (Commercial Off-The Shelf) products offer a potential solution.
Bliley Technologies has been recognized in the frequency control industry as one of the premier suppliers for high quality OCXOs for over 85 Years. Bliley has been moving up the value chain from an RF system perspective. Within the last year, Bliley has developed a commercial LEO solution to provide a master reference oscillator which provides the functionality of a PLL and OCXO from the GPSDO design and is currently in production.
The critical component that is becoming more apparent as a necessity for cubesatellite platforms is the GPS Disciplined Oscillator, GPSDO for short. GPSDOs comprise of a GPS receiver, Oven Controlled Crystal Oscillator (OCXO), and a Phased Locked Loop (PLL). The Global Navigation Satellite System (GNSS), in geo-stationary orbit, provides a GPS signal that many use today on the ground for navigation. With a GPS receiver (along with a GPS antenna) in place on board the satellite, a very precise 1 pulse per second signal can be generated from the signal transmitted from the GNSS (10-12 depending on how well the GPS receiver was designed). With the 1PPS signal from the GPS receiver, the OCXO can be steered using a phased locked loop. The PLL essentially compares a PPS signal derived from the OCXO to the 1PPS signal generated by the GPS receiver and a control circuit adjusts the OCXO frequency to synchronize both signals at the same timing offset (or phase). The GPS receiver is a great solution for long-term stability because OCXOs degrade over time with respect to stability, known as aging (i.e. increase in deviations over time from the desired frequency), and over temperature as well. This degradation is being compensated over time with the control circuitry in the PLL which that adjusts the frequency of the OCXO as the PLL is locking the derived PPS signal from the OCXO to the GPS 1PPS signal. However, short-term stability on the 1PPS signal from the GPS receiver is quite noisy due to atmospheric fluctuations, jitter within the GPS receiver, and other noise contributors. The use of a very stable OCXO for the GPSDO remedies this issue (ultra-stable quartz OCXOs can have short-term precision on the order of 10-12 or 10-13). The GPSDO design enables for a great short-term stability (from the OCXO) and long-term stability solution (from the 1PPS GPS signal). A system block diagram is provided below:
Small satellites have grown dramatically over the past decade... and they are still growing fast and furiously. In this post, you'll learn about how to achieve mission success for satellites and how GPS Disciplined Oscillators (GPSDOs) can do the trick.
Satellite communication touches our lives in ways most people don’t fully appreciate. From GPS to satellite TV to the communication networks that make modern economic, military and political affairs possible, there are few areas of life that the rise of SATCOM technology has not shaped in some way, directly or indirectly. While visions of massive arrays and constellations might be the first thing that comes to mind when some people think of satellites, today we’re going to focus on something a little less visually impressive but just as important; the Very Small Aperture Terminal, or “VSAT.”