From Dec. 4-5, 2024, the National Space-Based Positioning, Navigation and Timing (PNT) Advisory Board met to discuss GPS-related topics. The PNT Advisory Board provides independent advice to the U.S. government on GPS-related policy, planning, program management and funding profiles in relation to the current state of national and international satellite navigation services. A March 28, 2024, GPS World article by Dana Goward highlighted that the PNT Advisory Board has been providing the government with independent expert advice about GPS and PNT for 20 years. He highlighted that the Board is chaired by retired Admiral Thad Allen and has six subcommittees.
<figure class="wp-block-image size-large is-resized"><img fetchpriority="high" decoding="async" width="834" height="1024" src="https://coordinates.net/wp-content/uploads/2025/02/PNT-Subcommittees-834x1024-1.jpg" alt="Photo:" class="wp-image-108882" style="width:445px;height:auto" srcset="https://coordinates.net/wp-content/uploads/2025/02/PNT-Subcommittees-834x1024-1.jpg 834w, https://www.gpsworld.com/wp-content/uploads/2025/02/PNT-Subcommittees-244x300.jpg 244w, https://www.gpsworld.com/wp-content/uploads/2025/02/PNT-Subcommittees-171x210.jpg 171w, https://www.gpsworld.com/wp-content/uploads/2025/02/PNT-Subcommittees-768x943.jpg 768w, https://www.gpsworld.com/wp-content/uploads/2025/02/PNT-Subcommittees.jpg 943w" sizes="(max-width: 834px) 100vw, 834px" /></figure> <p>This newsletter will highlight a topic that the emerging capabilities, applications and sectors subcommittee discussed at the final PNT Advisory Board meeting of 2024. The presentation title is “GPS High Accuracy and Robustness Service (HARS)<strong><em>.” </em></strong>A <a href="https://www.gps.gov/governance/advisory/recommendations/2023-05-white-paper-GPS-HARS.pdf" target="_blank" rel="noopener">white paper</a> on the topic and the Dec. 4, 2024, <a href="https://www.gps.gov/governance/advisory/meetings/2024-12/peeri.pdf" target="_blank" rel="noopener">presentation</a> by Shachak Pe’eri, Ph.D., NOAA/NOS/National Geodetic Survey (NGS), can be found on the <a href="https://www.gps.gov/governance/advisory/" target="_blank" rel="noopener">PNT Advisory Board website</a>.</p> <p>According to the document, the board prepared the white paper to support recommendation number <a href="https://www.gps.gov/governance/advisory/recommendations/2023-01-PNTAB-27-chair-memo.pdf" target="_blank" rel="noopener">PNT27-04-ECAS</a>, which is to develop and implement a GPS HARS delivered to users via the Internet. The HARS concept was approved at the <a href="https://www.gps.gov/governance/advisory/meetings/2022-11/" target="_blank" rel="noopener">PNTAB-27 meeting (Nov. 16-17, 2022)</a> and formally submitted to the National Space-Based PNT EXCOM co-chairs via <a href="https://www.gps.gov/governance/advisory/recommendations/2023-01-PNTAB-27-chair-memo.pdf" target="_blank" rel="noopener">Memorandum on Jan. 27, 2023</a>.</p> <figure class="wp-block-image size-full"><img decoding="async" width="700" height="414" src="https://coordinates.net/wp-content/uploads/2025/02/700x400-PNT-27-04-11-22.jpg" alt="Recommandation PNT27-04. (Photo: Presentation by John W. Betz, PhD Member, National Space‐Based PNT Advisory Board on May 29, 2024)" class="wp-image-108883" srcset="https://coordinates.net/wp-content/uploads/2025/02/700x400-PNT-27-04-11-22.jpg 700w, https://www.gpsworld.com/wp-content/uploads/2025/02/700x400-PNT-27-04-11-22-300x177.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/700x400-PNT-27-04-11-22-245x145.jpg 245w" sizes="(max-width: 700px) 100vw, 700px" /><figcaption class="wp-element-caption">Recommendation PNT27-04. (Photo: Presentation by John W. Betz, PhD Member, National Space‐Based PNT Advisory Board on May 29, 2024)</figcaption></figure> <p>The November and <a href="https://www.gps.gov/governance/advisory/meetings/2024-12/" target="_blank" rel="noopener">December Advisory Board meetings</a> are recorded, and individuals can listen to the entire meeting. The <a href="https://www.gps.gov/governance/advisory/meetings/2024-12/" target="_blank" rel="noopener">Board’s website provides links</a> to the meeting agenda and presentations. Pe’eri’s presentation on HARS started at 10:30 am on Dec. 4 (2:04 on the recording).</p> <figure class="wp-block-image size-full is-resized"><img decoding="async" width="480" height="243" src="https://coordinates.net/wp-content/uploads/2025/02/National-Space-Based-PNT-Advisory-Board.png" alt="" class="wp-image-108885" style="width:460px;height:auto" srcset="https://coordinates.net/wp-content/uploads/2025/02/National-Space-Based-PNT-Advisory-Board.png 480w, https://www.gpsworld.com/wp-content/uploads/2025/02/National-Space-Based-PNT-Advisory-Board-300x152.png 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/National-Space-Based-PNT-Advisory-Board-245x124.png 245w" sizes="(max-width: 480px) 100vw, 480px" /></figure> <figure class="wp-block-image size-full is-resized"><img loading="lazy" decoding="async" width="600" height="360" src="https://coordinates.net/wp-content/uploads/2025/02/600x360-Picture1-2.jpg" alt="" class="wp-image-108888" style="width:586px;height:auto" srcset="https://coordinates.net/wp-content/uploads/2025/02/600x360-Picture1-2.jpg 600w, https://www.gpsworld.com/wp-content/uploads/2025/02/600x360-Picture1-2-300x180.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/600x360-Picture1-2-245x147.jpg 245w" sizes="(max-width: 600px) 100vw, 600px" /></figure> <p>Day 1 can be found <a href="https://www.youtube.com/watch?v=_ADPAOWpitI&t=8890s." target="_blank" rel="noopener">here</a>.</p> <p>During the meeting, the PNT Advisory Board officially stated that it supports the HARS Concept described by NOAA. Of course, the Board also stated that it has no money, but the Board’s stamp of approval of the concept is very important. Now, it is up to NOAA’s NGS to work with other federal agencies, such as NASA’s Jet Propulsion Laboratory (JPL), to work out the details and resources. By leveraging NASA’s real-time Global Differential GPS (GDGPS) System infrastructure and NOAA’s service delivery platforms, a high-accuracy, resilient service that ensures delivery of precise, reliable and secure GNSS corrections for a wide range of scientific and commercial applications can be built for the nation.</p> <p>So, what exactly is the GPS High Accuracy and Robustness Service (HARS)? The following is a statement from a<a href="https://www.gps.gov/governance/advisory/recommendations/2023-01-PNTAB-27-chair-memo.pdf" target="_blank" rel="noopener"> Jan. 27, 2023, PNT Memo</a>:</p> <p>“Implementing a GPS High Accuracy and Robustness Service: To augment GPS and overcome some inherent limitations of space-based PNT, <strong>the USG should provide a service comparable to the European Union’s Galileo HAS that provides signal corrections than enable better than one-meter level accuracy, as well as cryptographically-protected satellite navigation message data bits for integrity processing.</strong> The U.S. should develop and implement GPS HARS, based on the capabilities developed by the JPL for GDGPS, to be made available to users over the Internet.”</p> <p>The <a href="https://www.gps.gov/governance/advisory/recommendations/2023-05-white-paper-GPS-HARS.pdf" target="_blank" rel="noopener">white paper</a> describes the problem and the solution as the following:</p> <p>“<strong>The problem:</strong> GPS is falling behind other Global Navigation Satellite Systems (GNSSs) such as Europe’s Galileo and China’s Beidou. <strong>GPS has adopted an approach of allowing augmentation by third-party systems (such as Assisted-GNSS in mobile phones, WAAS for aviation accuracy and integrity, and commercial RTK for precision users), rather than providing specialized advanced services itself.</strong> Also, the data message modulated on the GPS signals is fragile. Environmental effects or malicious actions can prevent a receiver from reading the information or manipulate what is read, limiting the robustness of the GPS signals. Currently, GPS is the primary system in almost all GNSS chips, even chips made in Europe or Asia. That is: chips are designed to acquire GPS signals first, then signals from other systems. But Galileo and BeiDou are deploying high accuracy services that provide sub-meter position accuracy, enhancing satnav use in many civil applications. The absence of any plan for GPS to offer a similarly high accuracy service could cause GNSS chips to begin using Galileo or BeiDou, rather than GPS, as the primary system. A switch away from GPS as the primary PNT system is a problem for the US Government because it will lose its strategic advantage. Existing commercial chips are used in many strategically important US assets, such as airlines, ships, and organizations that support the US military. Once these chips change their architecture to Galileo-first or BeiDou-first, these strategic use cases depend on these services. It is one step in the direction of not having a GNSS system at all and borrowing the system of another power, exactly the situation that Europe and China were in before they built their own systems. GPS would no longer be the “pre-eminent space-based PNT service” called for in Space Policy Directive 7.”</p> <p>“<strong>The Solution:</strong> <strong>A high accuracy and robustness service (HARS) provides information to user receivers, reducing errors and enhancing the ability to operate in challenging conditions. </strong>The PNT Advisory Board has identified a solution that the U.S. government can provide a HARS without adding cost and complexity to GPS itself; instead, the needed information from government or government-sponsored organizations can be obtained and provided over the Internet to properly equipped receivers. The result would be a world-class HARS at a small fraction of the cost or time, compared to implementing it on new GPS satellites. The HARS would provide cryptographically-protected robust (resistant to jamming and spoofing) GPS for critical infrastructure and would enable new applications (such as lane-dependent route guidance in automobile navigation and emergency vehicle guidance, GPS-only precision positioning of drones) that extend the societal benefits of GPS. HARS would be secure and less sensitive to radio noise and disruptions, including spoofing.”</p> <p>The following are a few slides from Pe’eri’s presentation highlighting the need for HARS. He mentioned that there are six regional high accuracy systems and one global service that is already operational or in development. </p> <figure class="wp-block-image size-full is-resized"><img loading="lazy" decoding="async" width="600" height="340" src="https://coordinates.net/wp-content/uploads/2025/02/600x340-GPS-HARS.jpg" alt="Six regional HAS and one global HAS are operational or in development at this time. (Photo: NOAA/NGS) " class="wp-image-108889" style="width:738px;height:auto" srcset="https://coordinates.net/wp-content/uploads/2025/02/600x340-GPS-HARS.jpg 600w, https://www.gpsworld.com/wp-content/uploads/2025/02/600x340-GPS-HARS-300x170.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/600x340-GPS-HARS-245x139.jpg 245w" sizes="(max-width: 600px) 100vw, 600px" /><figcaption class="wp-element-caption">Six regional HAS and one global HAS are operational or in development at this time. (Photo: NOAA/NGS) </figcaption></figure> <p>NOAA’s presentation by Pe’eri was in response to a request by the Advisory Board. The Board was interested in learning more about the funding and operating a public service that can provide robust real-time GPS corrections. Summarized in three bullets:</p> <ul class="wp-block-list"> <li>High-Accuracy: Real-time corrections to GPS orbit parameters and clocks to enable more accurate positioning solutions.</li> <li>Robustness: Nav Data (ephemeris) can be cryptographically signed and delivered on the same channel.</li> <li>Service: Delivered over the Internet and is free to all users.</li> </ul> <figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="600" height="340" src="https://coordinates.net/wp-content/uploads/2025/02/PNT-Advisory-Board-to-NOAA-.jpg" alt="" class="wp-image-108890" srcset="https://coordinates.net/wp-content/uploads/2025/02/PNT-Advisory-Board-to-NOAA-.jpg 600w, https://www.gpsworld.com/wp-content/uploads/2025/02/PNT-Advisory-Board-to-NOAA--300x170.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/PNT-Advisory-Board-to-NOAA--245x139.jpg 245w" sizes="(max-width: 600px) 100vw, 600px" /></figure> <p>The HARS could be accomplished by employing the expertise, knowledge, and capabilities of NASA’s JPL and NOAA’s NGS.</p> <figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="600" height="340" src="https://coordinates.net/wp-content/uploads/2025/02/Complementary-partners.jpg" alt="Photo: NOAA" class="wp-image-108892" srcset="https://coordinates.net/wp-content/uploads/2025/02/Complementary-partners.jpg 600w, https://www.gpsworld.com/wp-content/uploads/2025/02/Complementary-partners-300x170.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/Complementary-partners-245x139.jpg 245w" sizes="(max-width: 600px) 100vw, 600px" /></figure> <p>NOAA has the authority to provide real-time operational services and regularly collaborates with other federal and state agencies and local communities. NGS manages and distributes the NOAA CORS Network (Foundation and Cooperative CORS). NASA JPL collects GNSS data and generates products with high accuracy.</p> <figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="600" height="340" src="https://coordinates.net/wp-content/uploads/2025/02/NOAA-knowledge.jpg" alt="NGS expertise and knowledge. (Photo: NGS/NOAA) " class="wp-image-108893" srcset="https://coordinates.net/wp-content/uploads/2025/02/NOAA-knowledge.jpg 600w, https://www.gpsworld.com/wp-content/uploads/2025/02/NOAA-knowledge-300x170.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/NOAA-knowledge-245x139.jpg 245w" sizes="(max-width: 600px) 100vw, 600px" /><figcaption class="wp-element-caption">NGS expertise and knowledge. (Photo: NGS/NOAA) </figcaption></figure> <p><a href="https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/GDGPS_daily_POD_orbits.html" target="_blank" rel="noopener">NASA’s GDGPS</a> is a complete, highly accurate and extremely robust real-time GNSS monitoring and augmentation system. The <a href="https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/GDGPS_daily_POD_orbits.html" target="_blank" rel="noopener">CCDIS</a> website states, “Employing a large ground network of real-time reference receivers, innovative network architecture, and real-time data processing software, the GDGPS System provides sub-decimeter (<10 cm) positioning accuracy and sub-nanosecond time transfer accuracy anywhere in the world, on the ground, in the air, and in space, independent of local infrastructure.”</p> <figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="1000" height="608" src="https://coordinates.net/wp-content/uploads/2025/02/1000x608-NASA.jpg" alt="Photo:JPL expertise and knowledge. (Photo: NASA) " class="wp-image-108894" srcset="https://coordinates.net/wp-content/uploads/2025/02/1000x608-NASA.jpg 1000w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x608-NASA-300x182.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x608-NASA-245x149.jpg 245w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x608-NASA-768x467.jpg 768w" sizes="(max-width: 1000px) 100vw, 1000px" /><figcaption class="wp-element-caption">JPL expertise and knowledge. (Photo: NASA) </figcaption></figure> <p>By leveraging <a href="https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/GDGPS_daily_POD_orbits.html" target="_blank" rel="noopener">NASA’s real-time GDGPS</a> System infrastructure and NOAA’s service delivery platforms, NGS and JPL can build a high-accuracy, resilient service that ensures delivery of precise, reliable and secure GNSS corrections for a wide range of scientific and commercial applications.</p> <figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="600" height="331" src="https://coordinates.net/wp-content/uploads/2025/02/600x331-Comp-efforts.jpg" alt="Photo: NOAA/NGS " class="wp-image-108895" srcset="https://coordinates.net/wp-content/uploads/2025/02/600x331-Comp-efforts.jpg 600w, https://www.gpsworld.com/wp-content/uploads/2025/02/600x331-Comp-efforts-300x166.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/600x331-Comp-efforts-245x135.jpg 245w" sizes="(max-width: 600px) 100vw, 600px" /></figure> <p>Pe’eri’s presentation highlighted HARS benefits to the daily operations of users of geospatial data.</p> <figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="581" src="https://coordinates.net/wp-content/uploads/2025/02/HARS-benefits-1024x581-1.jpg" alt="HARS benefits to users. (Photo: NOAA/NGS)" class="wp-image-108896" srcset="https://coordinates.net/wp-content/uploads/2025/02/HARS-benefits-1024x581-1.jpg 1024w, https://www.gpsworld.com/wp-content/uploads/2025/02/HARS-benefits-300x170.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/HARS-benefits-245x139.jpg 245w, https://www.gpsworld.com/wp-content/uploads/2025/02/HARS-benefits-768x436.jpg 768w, https://www.gpsworld.com/wp-content/uploads/2025/02/HARS-benefits-1536x871.jpg 1536w, https://www.gpsworld.com/wp-content/uploads/2025/02/HARS-benefits.jpg 1544w" sizes="(max-width: 1024px) 100vw, 1024px" /><figcaption class="wp-element-caption">HARS benefits for users. (Photo: NOAA/NGS)</figcaption></figure> <p>The HARS concept is extremely important to the U.S. GPS user community, where the number of users is increasing every day. A 2019 Department of Commerce (NIST) study, “<a href="https://www.nist.gov/system/files/documents/2020/02/06/gps_finalreport618.pdf" target="_blank" rel="noopener">Economic Benefits of the Global Positioning System (GPS),”</a> highlighted the economic damages a GPS outage would have on the agricultural industry.</p> <p>The 2019 NIST study, <a href="https://www.nist.gov/system/files/documents/2020/02/06/gps_finalreport618.pdf" target="_blank" rel="noopener">“Economic Benefits of the Global Positioning System (GPS),”</a> determined that $ 1.4 trillion in U.S. economic benefits from GPS. The study stated that a 30-day widespread outage could erode less than $ 1 billion in economic value per day. <strong>The study also highlighted the impact a GPS outage would have on Agriculture, stating that during planting season, economic damages in the agriculture sector could increase 30-day losses to $ 15 billion due to lower yields</strong>.</p> <p><span style="box-sizing: border-box; margin: 0px; padding: 0px;">Table ES-1 and figure ES-1 from the <a href="https://www.nist.gov/system/files/documents/2020/02/06/gps_finalreport618.pdf" target="_blank" rel="noopener">2019 report</a> highlight the economic benefits of GPS for private sector use.</span></p> <figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="1000" height="715" src="https://coordinates.net/wp-content/uploads/2025/02/1000x715-Advisory-Board-budget.jpg" alt="Table ES-1: Summary economic benefits of GPS for private-sector use, 1984 to 2017. (Photo: NIST) " class="wp-image-108907" srcset="https://coordinates.net/wp-content/uploads/2025/02/1000x715-Advisory-Board-budget.jpg 1000w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x715-Advisory-Board-budget-300x215.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x715-Advisory-Board-budget-245x175.jpg 245w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x715-Advisory-Board-budget-768x549.jpg 768w" sizes="(max-width: 1000px) 100vw, 1000px" /><figcaption class="wp-element-caption">Table ES-1: Summary of economic benefits of GPS for private-sector use, 1984 to 2017. (Photo: NIST) </figcaption></figure> <figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="1000" height="744" src="https://coordinates.net/wp-content/uploads/2025/02/1000x744-GPS-economic-benefits.jpg" alt="Figure ES-1: Time series of GPS's economic benefits for private sector. (Photo: NIST) " class="wp-image-108908" srcset="https://coordinates.net/wp-content/uploads/2025/02/1000x744-GPS-economic-benefits.jpg 1000w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x744-GPS-economic-benefits-300x223.jpg 300w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x744-GPS-economic-benefits-245x182.jpg 245w, https://www.gpsworld.com/wp-content/uploads/2025/02/1000x744-GPS-economic-benefits-768x571.jpg 768w" sizes="(max-width: 1000px) 100vw, 1000px" /><figcaption class="wp-element-caption">Figure ES-1: Time series of GPS’s economic benefits for the private sector. (Photo: NIST) </figcaption></figure> <p>I would encourage others to look at the PNT website, especially the Advisory Board website, to obtain information about space-based PNT. Other <a href="https://www.gps.gov/governance/advisory/recommendations/" target="_blank" rel="noopener">recommendations and letters</a> from the Advisory Board to the Executive Committee (EXCOM) can be found on the <a href="https://www.gps.gov/governance/excom/" target="_blank" rel="noopener">PNT </a><span style="box-sizing: border-box; margin: 0px; padding: 0px;">and Advisory Board websites</span>. The webpage provides the Advisory Board’s recommendations on ways to improve GPS and national GPS management. The recommendations are published in the interest of public transparency.</p> <p><p>The post <a rel="nofollow" href="https://www.gpsworld.com/the-gps-high-accuracy-and-robustness-service-hars/">The GPS High Accuracy and Robustness Service</a> first appeared on <a rel="nofollow" href="https://www.gpsworld.com">GPS World</a>.</p></p>
