Inside Frequency Control

GPS disciplined oscillators (GPSDOs) are becoming a necessary component for CubeSats and other small satellites (SmallSats).

GPSDOs are comprised of a Global Position System (GPS) receiver, an oven controlled crystal oscillator (OCXO), and a phased-locked loop (PLL). In this blog, you'll get a deeper look into how GPSDOs are designed to help achieve mission success for your small satellite applications.

While GPS technology plays an important role in modern navigation, it's not perfect. Although GPS might perform well enough consumer usage, signal jamming or other disruptions present serious threats to military operations. 

Enter assured positioning, navigation, and timing (A-PNT), new technology that enhances traditional GPS timing. Assured PNT uses additional sources to augment GPS and prevent vulnerabilities. Its goal is to ensure that accurate positioning, navigation, and timing (PNT) is always available.

In this blog, we'll review GPS, its flaws, and other PNT systems (like the GNSS) and give you an overview of how assured PNT technology uses other systems to improve effectiveness. 

GPS disciplined oscillators (GPSDO) are some of today's most trusted and accurate sources of timing. These powerful devices (sometimes called GPS clocks) consist of a high-quality stable oscillator and a GPS receiver. The GPSDO works by disciplining (or steering) the oscillator output to a GPS device or GNSS satellite signal via a tracking loop.

Before we dive into the differences between the 5 GNSS constellations... It's important that we're all on the same page with the difference between GNSS and GPS.

Many people get GNSS and GPS technology confused. A good way to think about the Global Navigation Satellite Systems (GNSS) is as the backbone (or underlying technology) behind GPS. The Global Positioning System (GPS) GPS is a GNSS constellation, but GNSS is not always GPS. GPS is one of the 5 GNSS constellations used around the world.

The 5 GNSS constellations include GPS (US), QZSS (Japan), BEIDOU (China), GALILEO (EU), and GLONASS (Russia). We'll cover each of these constellations in-depth in this post.

5G Fixed Wireless Access (FWA) will be one of the earliest uses of 5G. 5G FWA will provide lightning fast gigabit internet speeds to homes, apartments, and businesses. Better yet, 5G FWA will be a fraction of the cost compared to traditional cable & fiber systems.

The U.S Department of Homeland Security considers 13 of the nation’s 16 critical infrastructure sectors to be ‘critically dependent’ on PNT technology. Also, a loss of PNT would cost the U.S an estimated $10 BILLION a day. Not only do many everyday consumers use PNT & GPS on a daily basis, it's also crucial for military and intelligence operations. Other industries that strongly rely on GPS based PNT include

• Radio communications
• Network synchronization
• Intelligence systems
• Information gathering
• Cruise missiles
• Weapons systems
• Electronic warfare

Building resilience into Global Positioning System (GPS) timing and frequency receivers is crucial in the 21st century. Since the presidential directive on U.S Space-Based Position, Navigation, and Timing (PNT) and Critical Infrastructure Protection (PPD-21), federal agencies have been advancing their efforts when it comes to GPS and Global Navigation Satellite System (GNSS) capabilities. 

One of the most significant changes to the way the military operates has been the integration of GPS for positioning, navigation, and timing purposes, which has given military forces unprecedented command and control over battle grounds. Troops and command centers are now in a state of continuous situational awareness, with an endless stream of data being added to military servers at all time.