North American Datum of 1983 (NAD83) replaced NAD27 and was adopted as the official datum for California and the United States. It is an earth-centered datum based on ground control points and ... WGS84 and NAD83 can be considered equivalent. For example, data collected in WGS84 can be treated as NAD83, unless you are trying to map locations moreNAD83; up to 2 meters for WGS84 vs. NAD83 9/1/2020 2-14 Geo327G/386G: GIS & GPS Applications in Earth Sciences Jackson School of Geosciences, University of Texas at Austin NAD27, NAD83 & WGS 84 Coordinates Datum Latitude Longitude NAD27 30.283678 -97.732654 NAD83 30.283658 -97.732548 WGS84 30.283658 -97.732548 …A pesar que hace algún tiempo los Institutos Geográficos en Latino américa oficializaron el cambio a wGS84 como proyección estandarizada, el cambio a nivel de uso va un tanto lento. En realidad la proyección es siempre cilíndrica y el cambio apenas implica un cambio de Datum entre NAD27 y NAD83, no obstante las implicaciones se vuelven ...NAD_1983_CSRS_To_WGS_1984_2. The first is a 'bookkeeping' transformation that simply gets you between NAD83 CSRS and WGS84 (parameters are zeroes). The second assumes WGS 1984 = ITRF96 (1997.0) so it's pretty old. I think I've seen a newer transformation, but it might have been using an algorithm that we don't …While NAD83 and WGS84 may seem similar, there are some subtle differences between them. In most mapping, exploration, and GIS applications, coordinates in NAD83 and WGS84 will be practically identical. However, it is essential to note that these coordinates may differ by a few centimeters due to variations in the reference ellipsoid … NAD83 shaped ellipsoid centered at the ITRF origin to derive ITRF00 ellipsoid heights. Ellipsoid heights NAD83 vs. ITRF00 - Defined origins are best estimate of the center of mass; NAD83 is not geocentric. Move origin; move ellipsoid surface as indicated by scale shown on map. Ellipsoid height differences reflect the non-geocentricity of NAD83. NAD83; up to 2 meters for WGS84 vs. NAD83 8/31/2021 2-14 Geo327G/386G: GIS & GPS Applications in Earth Sciences Jackson School of Geosciences, University of Texas at Austin NAD27, NAD83 & WGS 84 Coordinates Datum Latitude Longitude NAD27 30.283678 -97.732654 NAD83 30.283658 -97.732548 WGS84 30.283658 -97.732548 8/31/2021 2-15 (Bellingham, WA)Bumetanide: learn about side effects, dosage, special precautions, and more on MedlinePlus Bumetanide is a strong diuretic ('water pill') and may cause dehydration and electrolyte ...In QGIS, use Layer > Add Layer > Add Vector Layer to open the source data file that uses NAD83. Then use Vector > Data Management Tools > Reproject Layer to start the process of transforming the coordinates. Be careful to get all the settings right at each step. Select the correct input layer. For the first pass, start with the layer containing ...UTM (Universal Transverse Mercator) is a coordinate system that is based on the WGS84 ellipsoid. The UTM system divides the Earth into 60 zones, each 6° of longitude in width. The grid zones UTM 31N to 37N differ from the standard zone for the Northern Hemisphere, in part to accommodate the southern half of the Kingdom of Norway.The ellipsoid and its accompanying anchor point that ties it in to the real world, are known collectively as the WGS84 datum. The WGS84 datum is what the constellations of GPS satellites use natively. UTM NAD83 is a projected coordinate system that represents physical locations abstracted to a flat, cartesian coordinate system. The …The GPS data is post-processed with Trimble Pathfinder office and exported as shapefiles into the local state plane coordinate system. The shapefiles are then imported into our SDE which is in WGS84 using the WGS_1984_ (ITRF00)_To_NAD_1983 Datum transformation. When comparing data exported from PostGIS to the data in our SDE they line up fine ... bound, etc.). The NAD 83 re f e r ence sys-tem, however, does make special accom-modations for certain U.S. regions that are located completely on another plate. In Hawaii, for example, NAD 83 positional coordinates are defined as if the Pacific plate is not moving. This approach is con-venient for people who are involved with Compare the coordinates in decimal degrees for Bellingham using NAD27, NAD83, and WGS84. It is apparent that while NAD83 and WGS84 express coordinates that are nearly identical, NAD27 is quite different, because the underlying shape of the earth is expressed differently by the datums and spheroids used. 1. Is NAD83 the same as WGS84? NAD83 and WGS84 are not the same but they are related. NAD83 is a regional datum specific to North America, while WGS84 is a global datum. However, they share a similar underlying reference ellipsoid, which means that conversions between the two can be relatively straightforward. 2.The Insider Trading Activity of McVey Richard M on Markets Insider. Indices Commodities Currencies StocksSummary . Both WGS 84, the datum used by GPS, and NAD 83, commonly used in North America, have been redefined several times since their beginning.Convierta fácilmente NAD83 a WGS84 con alta velocidad. Convertir de NAD83 a WGS84 es realmente rápido y fácil. Para obtener NAD83 a WGS84, ingrese las coordenadas en formato NAD83 en los campos, luego haga clic en el botón Convertir. Sus coordenadas NAD83 se convierten en WGS84 en menos de un minuto.We would like to show you a description here but the site won’t allow us.NAD83 is the national reference system used for georeferencing by most federal and provincial/state agencies while WGS84 is the default "native" system used by the Global …Here’s where to start with protein, creatine, and pre-workout.Go to Transformation tab and try the first three possible transformation paths ( <None>, WGS 1984 (ITRF08) To NAD 1983 2011, WGS 1984 (ITRF00) To NAD 1983 2011) and see if any of them aligns your data perfectly. The one that does is probably the path that was used by the Collector when converting your data to WGS84 Web Mercator …In this article, we will build a custom SoQL transformation expression that will reproject our CSV containing x and y coordinates in the NAD83 projection (used primarily in the pacific northwest) into WGS84. Adding Data and Launching Transformation. Start by adding your data file to the ingress revision using the “Add Data” button. Datum is an older term. The concept of a datum is included within a geographic coordinate system. A geographic transformation is always defined in a particular direction, like from NAD 1927 to WGS 1984. Transformation names will reflect this: NAD_1927_To_WGS_1984_1. The name may also include a trailing number, as the above example has _1. Vietnam is one of the world's fastest-growing tourist sites. Check out our detailed guide of the best ways to fly to Vietnam with points! We may be compensated when you click on pr...While NAD83 and WGS84 may seem similar, there are some subtle differences between them. In most mapping, exploration, and GIS applications, coordinates in NAD83 and WGS84 will be practically identical. However, it is essential to note that these coordinates may differ by a few centimeters due to variations in the reference ellipsoid …North American Datum of 1983 (NAD83) replaced NAD27 and was adopted as the official datum for California and the United States. It is an earth-centered datum based on ground control points and ... WGS84 and NAD83 can be considered equivalent. For example, data collected in WGS84 can be treated as NAD83, unless you are trying to map locations more UTM Zone 11 North or South? If it is South, it makes sense to use WGS84. North, I would use NAD83 over WGS84, but for most mapping applications it doesn't matter. There are lots of articles on the differences between the datums. Very simply, use NAD83 if all your data is in North America. Use WGS84 if your data is global. In their new definitions—NAD83 (2011) and WGS84 (G1762)—differ up to one or two meters within the continental United States. On the other hand, ITRF08, ITRF2014 and WGS84 (G1762) are virtually identical if their epochs (moment in time) are the same. The typical standard epoch for both are WGS84 (G1762) and ITRF08 is 2005.0.NAD83 is the national reference system used for georeferencing by most federal and provincial/state agencies while WGS84 is the default "native" system used by the Global Positioning System (GPS) and commercial GPS receivers.Positions obtained using the North American Datums of 1927 (NAD 27) and 1983 (NAD 83) are based on different earth shapes--or ellipsoids--and used the best technology available at the time. Mathematically, NAD 83 is a stronger datum because all previously existing horizontal stations and newer GPS surveyed stations were adjusted simultaneously.WGS84 isn't more accurate that NAD83. It just happens to be valid all over the earth, as compared to NAD83, which is valid only in North America. – Devdatta Tengshe. Jan 11, 2013 at 5:08. Agree with @Devdatta. WGS84 is universal compared to the other one, which is better suited for local applications. NAD83 would be more accurate …The NAD 83 and the NAVD 88 datums also provide the necessary linkages for Global Positioning System (GPS) data and are supported by GPS continuously operating reference stations. Refer to the above information about including the datum realization date and epoch and geoid model information when using coordinates developed from GNSS surveys.Thus I need a way to check my progress as I make corrections. At first just checking against google earth was fine, but at this point the 2.5 foot or so difference between my data (nad83) and google earth(wgs84) has become a limiting factor. So I need to transform nad83 to wgs84.Licensed attorney and retired Disability Rights Ohio executive director helps navigate the Americans with Disabilities Act. If you live with schizophrenia, then disclosing that dia...realization of NAD83 fixed to the North American tectonic plate. 2. Problems At the time of its initial realization, NAD83 was intended to be a geocentric system and was compatible with the other geocentric systems of the time, such as the original realization of WGS84. However, due to the use of more accurate techniques, it is now known thatWGS84 (World Geodetic System 1984) e NAD83 (North American Datum 1983) são sistemas de coordenadas geodésicas usados para definir posições na superfície da Terra. WGS84 é um sistema de coordenadas global amplamente utilizado em GPS e navegação por satélite. NAD83 é um sistema de coordenadas regional usado na América do Norte para fins de levantamento e mapeamento.Snap unveils AR Enterprise Services for businesses, enhancing customer engagement with immersive shopping experiences. Snap Inc., a leader in augmented reality (AR) technology, has...NAD27 vs. NAD83. NAD27 is based on the Clarke Ellipsoid of 1866, whereas NAD83 is based on the GRS 80 ellipsoid. The Clarke Ellipsoid is much less accurate. A point with a given latitude and longitude in NAD27 may be many tens of meters from another point having the identical latitude and longitude in NAD83.Web Mercator, Google Web Mercator, Spherical Mercator, WGS 84 Web Mercator [1] or WGS 84/Pseudo-Mercator is a variant of the Mercator map projection and is the de facto standard for Web mapping applications. It rose to prominence when Google Maps adopted it in 2005. [2] It is used by virtually all major online map providers, including Google ...Antifungal creams and medicines are used to treat fungal infections of the skin, scalp and nails. The length of treatment depends on what type of infection you have, and how severe...In 2022, the U.S., as part of its geodetic reference system modernization, will replace NAD83 with the new North American Terrestrial Reference Frame of 2022 (NATRF2022), resulting in 3D coordinate changes of up to 2 m. Along the Canada–U.S. boundary, horizontal differences will range from 1.3 to 1.5 m, as illustrated in Fig. 1.The 1980 Geodetic Reference System (GRS 80) posited a 6 m semi-major axis and a 298.257222101 flattening. This system was adopted at the XVII General Assembly of the International Union of Geodesy and Geophysics ( IUGG) in Canberra, Australia, 1979. The GRS 80 reference system was originally used by the World Geodetic System 1984 (WGS …How do the horizontal datums differ? Which should I use? What is HARN or HPGN? What are NGVD 29 and NAVD 88? Why did NGS change from NGVD 29 to NAVD 88? What is the relationship between the geodetic vertical datums (NGVD 29 and/or NAVD 88) and the various water level/tidal datums? What is WGS 84? Does it change? Answers...How do the horizontal datums differ? Which should I use? What is HARN or HPGN? What are NGVD 29 and NAVD 88? Why did NGS change from NGVD 29 to … An example compares the WGS84 location of the Texas state capitol dome to 13 other datums Largest (<200m) U.S. shifts typically from misapplying NAD27 to NAD83 data or vice-versa Shifts of <2 meter common for different realizations of NAD83; up to 2 meters for WGS84 vs. NAD83 8/31/2021 2-14 Often, industries that have great potential to be disrupted are also the most resistant to adopting bleeding-edge technology. While legacy sectors like transportation and energy ha...Learn the difference between the WGS84 and NAD83 datums, which are used for geographic and projected coordinate systems in ArcGIS. Find out how to label …The National Geodetic Survey (NGS) is replacing the two national datums used in the United States--the North American Datum of 1983 (NAD 83), the geometric datum used mainly for horizontal positions, and the North American Vertical Datum of 1988 (NAVD 88), the vertical datum used for determining orthometric heights (elevations)--by 2022.realization of NAD83 fixed to the North American tectonic plate. 2. Problems At the time of its initial realization, NAD83 was intended to be a geocentric system and was compatible with the other geocentric systems of the time, such as the original realization of WGS84. However, due to the use of more accurate techniques, it is now known thatMar 30, 2024 · These systems play a crucial role in mapping, exploration, and geographic information systems (GIS). Understanding the differences between WGS84 and NAD83 is important to ensure accurate positioning and coordinate referencing. WGS84, which stands for World Geodetic System 1984, is the … What is WGS84 vs NAD83? Read More » The current WGS84 realization is called WGS84(G1150). NAD83 – WHICH NAD83? Well, the same story applies to the NAD83 datum ex cept that the purpose is slightly different: while WGS84 intends to track the center of mass of the Earth, the NAD83 datum intends to track the movement of the North American plate. Not surprisingly the two datums that ... North American Datum of 1983 (NAD83) replaced NAD27 and was adopted as the official datum for California and the United States. It is an earth-centered datum based on ground control points and ... WGS84 and NAD83 can be considered equivalent. For example, data collected in WGS84 can be treated as NAD83, unless you are trying to map locations moreI am a bit of a novice gis user, and my geographic understanding is fairly basic. I Understand that WGS84 and NAD83 are two different datums, and that typically UTM Coordinates are based on the WGS datum. However I am working on a project that requires us to report the coordinates of many different sites in UTM coordinates on the NAD83 datum. The original WGS 84 realization essentially agrees with NAD 83 (1986). It is generally assumed, and this assumption is substantiated by the National Geodetic Survey, that WGS 84 (original) is identical to NAD 83 (1986). In 1994, DoD introduced a realization of WGS 84 that was based completely on GPS observations. Where: h NAD 83(2011) is the GPS derived ellipsoid height with respect to NAD83(2011). H NAVD 88 is the orthometric height derived from leveling with respect to NAVD 88. (In Puerto Rico and U.S. Virgin Islands, this is with respect to PRVD02 and VIVD09, respectively) N xGEOID19B is the gravimetric geoid height The GPS on bench …WGS84 and NAD83 are not, themselves projections, but coordinate systems differing by the datum (or 'representations of the spheroidal earth, defined mathematically') that they use. Imagine two points which have almost no horizontally spacing, but one very high up in the air and one close to the ground.Here's how to convert New Jersey coordinates to UTM: First, add the NJ SPCS, as described above. Enter your data in New Jersey, paste it in from Excel, or import a shapefile or CAD drawing by clicking Import on the File menu. ExpertGPS Pro will convert your state plane coordinates and display them over a topo map or aerial photo of New Jersey.New Datums: Replacing NAVD 88 and NAD 83. Preview the Modernized NSRS on the NGS Alpha Web Site! To improve the National Spatial Reference System (NSRS), NGS will replace all three North American Datum of 1983 (NAD 83) frames and all vertical datums, including the North American Vertical Datum of 1988 (NAVD 88), with four new terrestrial ...Depending on one’s location, coordinates obtained using NAD83 could be hundreds of meters away from coordinates obtained using NAD27. The World Geodetic System of 1984 (WGS84) is identical to NAD83 for most practical purposes within the United States. WGS84 is the default datum setting for almost all GPS devices.Any recent NAD83 (NSRS2007, 2011, probably CORS96 because it was used later than 1996 and possibly HARNs) versus WGS84/ITRF is now up to 1 m or more. Within NAD83, biggest jump was from original to the first HARN within a state. Some states have a 2nd or 3rd HARN / FBN adjustment which will be smaller.v. t. e. A geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame) is a global datum reference or reference frame for precisely representing the position of locations on Earth or other planetary bodies by means of geodetic coordinates. [1] Datums [note 1] are crucial to any ...New Datums: Replacing NAVD 88 and NAD 83. Preview the Modernized NSRS on the NGS Alpha Web Site! To improve the National Spatial Reference System (NSRS), NGS will replace all three North American Datum of 1983 (NAD 83) frames and all vertical datums, including the North American Vertical Datum of 1988 (NAVD 88), with four new terrestrial ...Jun 10, 2020 · The purpose of GEOID18 is to return a geoid height that is consistent with the published NAVD 88 orthometric heights on NGS Data Sheets when used with GPS-derived NAD 83 (2011) epoch 2010.0 ellipsoid heights. NGS has chosen to use the term estimated uncertainties which is intended to refer to how well the GEOID18 model performs this task. GRS80 / WGS84 (NAD83) Airy 1858 Airy Modified Australian National Bessel 1841 Clark 1880 Everest 1830 Everest Modified Fisher 1960 ... WGS 72 User defined. Please note that the GRS80 and WGS84 are considered to be the same. Actually, there is a very small difference in the flattening which results in the semi-minor axis, b, being different by 0 ... How large is the North American Datum of 1927 (NAD 27) to NAD 83 shift? Within the conterminous 48 states, the North American Datum of 1927 (NAD 27) to the North American Datum of 1983 (NAD 83) shift of the latitude/longitude graticule (lines showing parallels of latitude and meridians of longitude for the earth) is in the range of 10-100 ... 4. The NAD 27 and the NAD 83 are different in their ellipsoids. 5. When talking about accuracy, it has been said that the North American Datum of 1983 is more accurate than the North American Datum of 1927. 6. The NAD 83 uses modern technology; the NDA 27 has been done only manually. Author.Vietnam is one of the world's fastest-growing tourist sites. Check out our detailed guide of the best ways to fly to Vietnam with points! We may be compensated when you click on pr...The World Geodetic System (WGS) is a standard used in cartography, geodesy, and satellite navigation including GPS.The current version, WGS 84, defines an Earth-centered, Earth-fixed coordinate system and a geodetic datum, and also describes the associated Earth Gravitational Model (EGM) and World Magnetic Model (WMM). The standard is … An example compares the WGS84 location of the Texas state capitol dome to 13 other datums Largest (<200m) U.S. shifts typically from misapplying NAD27 to NAD83 data or vice-versa Shifts of <2 meter common for different realizations of NAD83; up to 2 meters for WGS84 vs. NAD83 8/31/2021 2-14 WGS84とNAD83の違いは、参照楕円体です。. 北米測地系は測地座標（GRS80）を使用し、WGS84は1984年の惑星測地システム（WGS84）によって使用されています。. これらの楕円体の測定値は異なります。. WGS-84は、飛行ビジネスに地球の標準的な整理参照構造を提供し ...What is NAD83 in GIS? NAD83 is an acronym for North American Datum of 1983, a geocentric datum and geographic coordinate system based on the 1980 Geodetic Reference System ellipsoid (GRS80). It is mainly used in North America and provides measurements obtained from both terrestrial and satellite data. What is the difference …North American Datum of 1983 (NAD83) replaced NAD27 and was adopted as the official datum for California and the United States. It is an earth-centered datum based on ground control points and ... WGS84 and NAD83 can be considered equivalent. For example, data collected in WGS84 can be treated as NAD83, unless you are trying to map locations moreThe equity round is led by the Canadian Business Growth Fund (CBGF) and Investissement Québec (IQ). New investors also include Export Development ... The equity round is led by the...Fluid Overload is more fluid than the heart can effectively cope with. Fluid overload (hypervolemia) occurs when the circulating volume is excessive. Try our Symptom Checker Got an...Convierta fácilmente NAD83 a WGS84 con alta velocidad. Convertir de NAD83 a WGS84 es realmente rápido y fácil. Para obtener NAD83 a WGS84, ingrese las coordenadas en formato NAD83 en los campos, luego haga clic en el botón Convertir. Sus coordenadas NAD83 se convierten en WGS84 en menos de un minuto.The Fed is being forced to help banks and put its battle against inflation on hold. Two weeks ago the main focus of market participants was whether inflation would stay elevated an...The World Geodetic System of 1984 (WGS84) is identical to NAD83 for most practical purposes within the United States. WGS84 is the default datum setting for almost all …Convert to WGS84 converts coordinates to WGS84 system. The original coordinates can be in the system: UTM, GPS / WGS84, NAD83, and other popular systems. Optionally, you can select the system by entering the EPSG code. The EPSG registry database consists of over 1000 entries.Except for the largest map scales, the horizontal components of WGS 84 and NAD 83 may be considered equivalent. Even if the features are horizontally referenced to NAD 83, this …KML Import&Export, Carlson Survey, NAD83 vs WGS84. Posted by toeknee on August 16, 2023 at 5:09 pm. After a few experiments, it appears that Carlson Survey (I’m using 2023) exports KML/KMZ files from my drawings with NAD83 lat/lon coordinates, and this because I work in NAD83-based state plane coordinates. My drawing and coordinate files in ...For example, the latitude and longitude location in a NAD27 datum differs from that same benchmark in NAD83 or WGS84. This difference is known as a datum shift. Depending on where you are in North America, NAD27 and NAD83 may differ in tens of meters for horizontal accuracy.For general mapping purposes, WGS84 and NAD83 can be considered equivalent. For example, data collected in WGS84 can be treated as NAD83, unless you are trying to map locations more accurately than about 1 meter. 4. Projections and coordinate systems used in California
That’s why the U.S. National Geodetic Survey is now modernizing its National Spatial Reference System (NSRS). They will replace NAD83 as their national geometric reference system with the North American Terrestrial Reference Frame of 2022 (NATRF2022). This update was originally planned for 2022 but has been delayed until …. Honda brownsville tx
Mar 28, 2024 · WGS84 is not an option in the conversion tool. If I have records from all over the world then which NAD 83 do I use in place of WGS84? For now, you may use HTDP to transform WGS84 to NAD 83 first and use the transformed NAD 83 coordinates in NCAT. Future versions of NCAT may support WGS84. You may access HTDP from here In their new definitions—NAD83 (2011) and WGS84 (G1762)—differ up to one or two meters within the continental United States. On the other hand, ITRF08, ITRF2014 and WGS84 (G1762) are virtually identical if their epochs (moment in time) are the same. The typical standard epoch for both are WGS84 (G1762) and ITRF08 is 2005.0.GRS80 / WGS84 (NAD83) Airy 1858 Airy Modified Australian National Bessel 1841 Clark 1880 Everest 1830 Everest Modified Fisher 1960 ... WGS 72 User defined. Please note that the GRS80 and WGS84 are considered to be the same. Actually, there is a very small difference in the flattening which results in the semi-minor axis, b, being different by 0 ...New Datums: Replacing NAVD 88 and NAD 83. Preview the Modernized NSRS on the NGS Alpha Web Site! To improve the National Spatial Reference System (NSRS), NGS will replace all three North American Datum of 1983 (NAD 83) frames and all vertical datums, including the North American Vertical Datum of 1988 (NAVD 88), with four new terrestrial ...Here's how to convert New Jersey coordinates to UTM: First, add the NJ SPCS, as described above. Enter your data in New Jersey, paste it in from Excel, or import a shapefile or CAD drawing by clicking Import on the File menu. ExpertGPS Pro will convert your state plane coordinates and display them over a topo map or aerial photo of New Jersey.AIDS activism defines the blueprint of how to hold the government accountable in the face of a health crisis. Larry Kramer, America’s most prominent AIDS activist, died yesterday ...NAD83; up to 2 meters for WGS84 vs. NAD83 8/31/2021 2-14 Geo327G/386G: GIS & GPS Applications in Earth Sciences Jackson School of Geosciences, University of Texas at Austin NAD27, NAD83 & WGS 84 Coordinates Datum Latitude Longitude NAD27 30.283678 -97.732654 NAD83 30.283658 -97.732548 WGS84 30.283658 -97.732548 …o 2.2 m offset – NAD83 vs. ... • World Geodetic System 1984 (WGS84) o CORS <> passive network “disconnect” vs. ITRF/WGS84. Future Geometric (3-D) Reference Frames replace NAD83 with new geometric reference frames – by …In 2022, the U.S., as part of its geodetic reference system modernization, will replace NAD83 with the new North American Terrestrial Reference Frame of 2022 (NATRF2022), resulting in 3D coordinate changes of up to 2 m. Along the Canada–U.S. boundary, horizontal differences will range from 1.3 to 1.5 m, as illustrated in Fig. 1.Snap unveils AR Enterprise Services for businesses, enhancing customer engagement with immersive shopping experiences. Snap Inc., a leader in augmented reality (AR) technology, has...WGS84 (World Geodetic System 1984) is a global reference system, whereas NAD83 (North American Datum 1983) is a regional one specific to North America. …Google Earth (also Google Maps and Microsoft Virtual Earth) use a Mercator projection based on a spherical datum (in ESRI parlance, datum = “Geographic Coordinate System; GCS”) that is a modification of the WGS84 datum. The “true” WGS84 datum is ellipsoidal (GRS80 ellipsoid) and geocentric; only the geocentric aspect is common to both.What you need to know is that the SparkFun RTK product line outputs coordinates in the WGS84 coordinate system by default and can output ECEF as well. Most of the coordinates by the NGS are NAD83 which has about a 1.5-meter difference from the WGS84 coordinate system. No big deal for general mapping but it'll throw a wrench in your testing if ...NAD 83 is based on the adjustment of 250,000 points including 600 satellite Doppler stations which constrain the system to a geocentric origin." (Geodetic Glossary, pp 57) Why did NGS change from NAD 27 to NAD 83? NAD 83 was computed by the geodetic agencies of Canada (Federal and Provincial) and the National Geodetic Survey for several reasons. between NAD83 and the various ITRFs for use with the new realizations of WGS84, the bias between NAD83 and WGS84 was never acknowledged by the agency maintaining WGS84. Consequently, the vast majority of GPS receiver manufactures continue to treat NAD83 as being identical with the new realizations of WGS84 which results in position .