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Auvergne Test


In 2004, the French Institut Géographique National (IGN), upon the request of the steering committee of the European Gravity and Geoid Project, prepared a dataset to test geoid computation methods and software. The Auvergne region, located in the centre of France, was selected as the target area. The dataset consists of about 240,000 gravity points, a digital terrestrial model and 75 GPS/levelling points, allowing for the computation and evaluation of a 3°×2° geoid is feasible.

Auvergne Dataset

Author: H. Duquenne, IGN/LAREG
Version: 4
Date: Jan 17, 2008


Levelled GPS points:

  • File Name: GPS_LEV.PTS
  • Contents: levelled GPS points from the “French Basic Network” and the so called “NIVAG” dataset. Number of points = 75.
  • Geographic Limits: 45° ≤ ϕ ≤ 47°, 1.5° ≤ λ ≤ 4.5°
  • Format: text ASCII
  • Separator: space(s)
     ColumnsType of dataDataUnitReference system
     1 - 9 numeric, integeridentifier    
     12 - 21 numeric, float latitude decimal degree RGF93/ETRS89
     23 - 33 numeric, float longitude decimal degree RGF93/ETRS89
     35 - 44 numeric, float normal height metre NGF-IGN69
     46 - 54 numeric, float ellipsoidal height metre RGF93/ETRS89
  • File Download: click here [4.1 KB]

Gravity points:
  • File Name: GRAVI_V3.PTS
  • Contents: gravity points from BGI database, with an evaluated accuracy of 0.25~0.75 mGal. Number of points = 244,009.
  • Geographic Limits: 43° ≤ ϕ ≤ 49°, −1° ≤ λ ≤ 7°
  • Format: text ASCII
  • Separator: space(s)
     ColumnsType of dataDataUnitReference system
     1 - 8numeric, integeridentifier    
     10 - 20numeric, float latitude decimal degree RGF93/ETRS89
     22 - 32numeric, float longitude decimal degree RGF93/ETRS89
     34 - 41numeric, float normal height metre NGF-IGN69 (Potsdam + 1930)
     43 - 50numeric, float orthometric height metre NGF-IGN69 (IGSN71)
     52 - 59numeric, float ellipsoidal height metre RGF93/ETRS89
     61 - 70numeric, float gravity m/s**2 IGSN71
     72 - 79numeric, float free-air gravity anomaly mGal IGSN71, GRS80, NGF-IGN69
  • File Download: click here [18.8 MB]

Digital terrain model:
  • File Name: H_MSL_CGIAR_V3.DTM
  • Contents: digital terrain model (height above EGM96 geoid model) from SRTM USGS/NASA data.
  • Geographic Limits: 42° ≤ ϕ ≤ 50°, − 2° ≤ λ ≤ 8°
  • Format: text ASCII
  • Separator: space(s)
  • Header: 3 rows, 2 data per row
     Row 1:min_latitude max_latitude(unit: decimal degree)
     Row 2: min_longitude max_longitude (unit: decimal degree)
     Row 3:latitude_spacing longitude_spacing (unit: decimal degree)
  • Body: heights, from North to South and, for each latitude, from West to East (longitude varies more quickly)
  • Unit: metre
  • Logical format: 9601 rows, 12001 columns
  • Physical format: 9601 blocks of (1200 rows of 10 values + 1 row of 1 value + 1 empty row) values are numeric integer, coded with 5 digits separated by 1 space
  • File Download: click here [144.0 MB]
  • Declaration: The DTM "H_msl_cgiar_v3.dtm" has been built from SRTM USGS/NASA data processed by CIAT, version 3. Users are prohibited from any commercial, non-free resale, or redistribution without explicit written permission from CIAT. Users should acknowledge CIAT as the source used in the creation of any reports, publications, new data sets, derived products, or services resulting from the use of this data set. CIAT also request reprints of any publications and notification of any redistributing efforts. Users are kindly asked to cite this data in any published material produced using this data, and if possible link web pages to the CIAT SRTM website (http://srtm.csi.cgiar.org).
  • Citation: A. Jarvis, H.I. Reuter, A. Nelson, E. Guevara (2006). Hole-filled seamless SRTM data V3. International Centre for Tropical Agriculture (CIAT), available from http://srtm.csi.cgiar.org.

Auvergne solutions


Year Name       Authors   
Institutions Computation method          Status
DOI
2006 QGAuvergne H. Duquenne IGN (France)
Spherical FFT (GRAVSOFT) PUBLIC  
2017 AuvGeoid2017 Janák et al. STU-UNB (Slovakia-Canada)
UNB Stokes-Helmert's approach PUBLIC  
2019 AuvGeoid2019 Foroughi et al. UNB-SUT-NTIS (Canada-Iran-Czech Republic)
UNB Stokes-Helmert's approach PUBLIC  
2019 AuvGeoid2019-OneStep Goli et al. SUT-UNB-NTIS (Iran-Canada-Czech Republic)
One-step integration method PUBLIC  
2021 Auvergne-ITUGRG2021 Sakil et al. ITU-GRG (Turkey)
Least Squares Modification of Hotine's Integral with Additive Corrections PUBLIC  



References

H. Duquenne (2006). A data set to test geoid computation methods. Proceedings of the 1st International Symposium of the International Gravity Field Service, Istanbul, Turkey, Harita Dergisi, pp. 61-65.

Bouron, P. (2004). Entretien du NGF avec assistance GPS (NIVAG) – Spécifications de produit. Technical report nr. IT 244, Service de Géodésie et Nivellement, Institut Géographique National (in French).

SGN (1996). Spécifications du Réseau de Base Français. Version 2.2. Technical report nr. IT 152, Service de Géodésie et Nivellement, Institut Géographique National (in French).

D. Toustou (1991). Chaîne de validation interactive de données gravimétriques: DIVA. Note technique n° 10, Bureau Gravimétrique International (in French).