[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-230356-105":59,"doc-detail-230356-en":131},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":124,"head_meta":126,"extra_data":128,"updated_unix":130},105,"en","aircraft-positioning-for-airborne-gravimetry-day-2","Aircraft Positioning for Airborne Gravimetry - Day 2","","Airborne gravimetry depends on precise position, navigation, and timing (PNT) to ensure aircraft motion follows planned tracks and each gravity and IMU sample is time- and location-stamped in real time. The material explains why improved positioning and attitude reduce errors in gravity measurements, outlining real-time navigation needs, terminology for navigation, positioning, attitude, and trajectory, and GNSS-based positioning concepts. It also contrasts positioning methods and describes coupled GNSS + IMU processing and GRAV-D positioning implementation examples, including GNSS products and latency.",{"@graph":69,"@context":123},[70,84,106],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/aircraft-positioning-for-airborne-gravimetry-day-2/230356/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/aircraft-positioning-for-airborne-gravimetry-day-2/230356.png","ImageObject",300,407,{"name":92,"@type":93},"WPS_1786070896","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-06","2026-09-10",true,{"@type":102,"interactionType":103,"userInteractionCount":105},"InteractionCounter",{"@type":104},"ViewAction",15,{"@type":107,"mainEntity":108},"FAQPage",[109,115,119],{"name":110,"@type":111,"acceptedAnswer":112},"What PNT capabilities are required for airborne gravimetry during data collection?","Question",{"text":113,"@type":114},"The material requires real-time navigation along pre-planned tracks, GNSS time-and-location stamping for each gravity and IMU sample, real-time position input to the gravimeter for mechanical feedback, and post-processing of precise position and orientation into a usable trajectory for gravity corrections.","Answer",{"name":116,"@type":111,"acceptedAnswer":117},"How does positioning accuracy affect gravity data quality?",{"text":118,"@type":114},"Gravity is measured as total acceleration, and gravity corrections depend on positioning and attitude. Minimizing aircraft positioning errors directly reduces errors in the resulting gravity measurements.",{"name":120,"@type":111,"acceptedAnswer":121},"What is the difference between navigation, positioning, attitude, and trajectory in the GNSS context?",{"text":122,"@type":114},"Navigation focuses on plotting and correcting relative position, velocity, and attitude to follow a route. Positioning provides absolute position/velocity/attitude over time relative to a reference. Attitude describes orientation and rates (pitch, roll, yaw/heading). Trajectory is the time-series history of position, velocity, and orientation.","https://schema.org",{"og:url":83,"og:type":125,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":127,"canonical":83},"index,follow",{"doc_id":129,"site_id":62},230356,1789049426,{"code":4,"msg":5,"data":132},{"doc_id":129,"user_id":133,"nickname":92,"user_avatar":134,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":105,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":140,"language":141,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":142,"faqs":143,"seo_title":144,"seo_description":67,"update_tm":130,"read_time":145,"preview_page_count":4},549768072016,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","Aircraft Positioning for Airborne Gravimetry  \nDr. Theresa Damiani  \nNOAA-National Geodetic Survey  \nDay 2: Airborne Gravity Data Collection and Processing  \nTuesday, May 24, 2016  \nOutline  \nI. Position, Navigation, and Timing (PNT) Needs of Airborne Gravimetry  \nII. PNT overview-How Global Navigation Satellite Systems (GNSS) work  \nIII. Kinematic positioning with GNSS  \nIV. Coupled kinematic positioning with GNSS + IMU  \nV. GRAV-D examples of positioning implementation  \nPosition, Navigation, and Timing (PNT) Needs of Airborne Gravimetry  \nPart I  \nPNT Needs for Airborne Gravity  \n1. Real-time navigation of the aircraft along pre-planned tracks, resulting in smooth motion of the aircraft.  \n2. Real-time GNSS stamp of location and time to each sample of collected raw gravity and IMU data.  \n3. Real-time position input togravimeter, for mechanical feedback during operation .  \n4. Post-Processing precise position and orientation data into a trajectory for use in gravity corrections .  \nGravity corrections relying on positioning and attitude  \nGravimeters measure the TOTAL acceleration they experience .  \nGenerally:  \na measured = g + aaircraft_vertical + corrections + calibration + drift  \nMinimizing errors in your aircraft’s positioning will decrease  \nthe errors in your gravity data!  \nPNT overview-How GNSS works  \nPart II  \nPNT Terminology  \n• Navigation:  \n– Actively plotting, ascertaining, and correcting relative position, velocity, and attitude in order to follow a route  \n– Real-time,“Where am I with respect to where I want to go?”  \n• Positioning:  \n– Finding absolute position, velocity, and attitude over time with respect to a pre-defined reference .  \n– Real-time and post-processed,“Where is/was I on Earth?”  \n• Attitude:  \n– The acceleration, orientation, rates; pitch, roll, yaw, heading.  \n– Real-time and post-processed,“How was I moving?”  \n• Trajectory:  \n– The history (time series) of position, velocity, and orientation .  \n– The result of post-processed positioning,“This is where it was .”  \nPNT Methods for Scientific Aircraft  \n• Navigation:  \n– Maps, aircraft instruments, radio aides, dead reckoning, autopilots, INS ( Inertial Navigation Systems = GNSS + Inertial Measurement Unit (IMU))  \n• Positioning:  \n– GNSS (Global Navigation Satellite Systems) including GPS (U.S. Global Positioning System), GLONASS (Russia), GALILEO (E.U.), BeiDou (China), QZSS (Japan), and IRNSS (India); Also, INS.  \n• Attitude:  \n– IMU, GNSS antenna array, aircraft avionics recordings  \n• Trajectory:  \n– Post-processing software for GNSS and IMU data, with respect to a particular point on or inside the aircraft.  \nHow does GNSS work?  \nExample: GPS (Global Positioning System, U.S) Constellation of Satellites (left) and Ground Control Stations (right)  \n• Satellites orbit the planet so that there are 4 or more visible from every location on the surface; their orbital period is ~12 hours and altitude is ~20,000 km .  \n• Other GNSS in orbit increase the number of possible visible satellites .  \n• All GNSS transmit several frequencies of relatively weak, ultra-high frequency (UHF) radio signals to Earth, encoded with information .  \n• Satellites’ orbits are tracked by world-wide systems of ground stations. [http://www.gps.gov/s](http://www.gps.gov/s)ystems/gps/control/  \nIGS GPS Satellite Ephemeris & Clocks  \nInternational GNSS Service  \nDOWNLOAD ONLINE:  \n[https://igscb.jpl. nasa.gov/components/prods.html](https://igscb.jpl. nasa.gov/components/prods.html)  \n\n| Product Name | Information | Accuracy | Latency |\n| --- | --- | --- | --- |\n| Broadcast (transmitted by satellite) | Orbits | ~100 cm | Real-Time |\n|  | Satellite Clocks | ~5 ns RMS, ~2.5 ns Std. Dev. |  |\n| Ultra-Rapid (2 nd 24 hours, predicted half) | Orbits | ~5 cm | Real-Time |\n|  | Satellite Clocks | ~3 ns RMS, ~1.5 ns Std. Dev. |  |\n| Ultra-Rapid (1st 24 hours, observed half) | Orbits | ~3 cm | 3 – 9 hours |\n|  | Satellite Clocks | ~ 150 ps RMS, ~50 ps Std. Dev. |  |\n| Rapid ","cbCaiuycRxcRM0gf","https://ap.wps.com/l/cbCaiuycRxcRM0gf","pdf",1703346,45,"English","# Outline\n## Position, Navigation, and Timing (PNT) Needs of Airborne Gravimetry\n## PNT overview-How Global Navigation Satellite Systems (GNSS) work\n## Kinematic positioning with GNSS\n## Coupled kinematic positioning with GNSS + IMU\n## GRAV-D examples of positioning implementation\n# Position, Navigation, and Timing (PNT) Needs of Airborne Gravity\n## PNT Needs for Airborne Gravity\n## Gravity corrections relying on positioning and attitude\n# PNT overview-How GNSS works\n## PNT Terminology\n## PNT Methods for Scientific Aircraft\n## How does GNSS work?","[{\"question\":\"What PNT capabilities are required for airborne gravimetry during data collection?\",\"answer\":\"The material requires real-time navigation along pre-planned tracks, GNSS time-and-location stamping for each gravity and IMU sample, real-time position input to the gravimeter for mechanical feedback, and post-processing of precise position and orientation into a usable trajectory for gravity corrections.\"},{\"question\":\"How does positioning accuracy affect gravity data quality?\",\"answer\":\"Gravity is measured as total acceleration, and gravity corrections depend on positioning and attitude. Minimizing aircraft positioning errors directly reduces errors in the resulting gravity measurements.\"},{\"question\":\"What is the difference between navigation, positioning, attitude, and trajectory in the GNSS context?\",\"answer\":\"Navigation focuses on plotting and correcting relative position, velocity, and attitude to follow a route. Positioning provides absolute position/velocity/attitude over time relative to a reference. Attitude describes orientation and rates (pitch, roll, yaw/heading). Trajectory is the time-series history of position, velocity, and orientation.\"}]","Aircraft Positioning for Airborne Gravimetry - Day 2 | PDF",113]