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         Geoplanning 
Vol 4, No. 1, 2017, 19-26                                                                                                                                                           Journal of Geomatics and Planning 

                                                                                                 E-ISSN: 2355-6544 
http://ejournal.undip.ac.id/index.php/geoplanning 

doi: 10.14710/geoplanning.4.1.19-26 

COORDINATE TRANSFORMATION USING FEATHERSTONE AND VANÍČEK PROPOSED 
APPROACH - A CASE STUDY OF GHANA GEODETIC REFERENCE NETWORK 

Y. Y. Ziggah a, b, J. Ayer c, P. B. Laari  d, E. Frimpong b 

a Department of Surveying and Mapping, China University of Geosciences, Wuhan, 430074, P.R. China. 
b Department of Geomatic Engineering, University of Mines and Technology, Tarkwa, Western Region, Ghana. 
c Department of Geomatic Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ashanti Region, Ghana. 
d Department of Environment and Resource Studies, University for Development Studies, Tamale, Ghana. 
 

Abstract: Most developing countries like Ghana are yet to adopt the geocentric datum 

for its surveying and mapping purposes. It is well known and documented that non-
geocentric datums based on its establishment have more distortions in height 
compared with satellite datums. Most authors have argued that combining such height 
with horizontal positions (latitude and longitude) in the transformation process could 
introduce unwanted distortions to the network. This is because the local geodetic 
height in most cases is assumed to be determined to a lower accuracy compared with 
the horizontal positions. In the light of this, a transformation model was proposed by 
Featherstone and Vaníček (1999) which avoids the use of height in both global and 
local datums in coordinate transformation. It was confirmed that adopting such a 
method reduces the effect of distortions caused by geodetic height on the 
transformation parameters estimated. Therefore, this paper applied Featherstone and 
Vaníček (FV) model for the first time to a set of common points coordinates in Ghana 
geodetic reference network. The FV model was used to transform coordinates from 
global datum (WGS84) to local datum (Accra datum). The results obtained based on 
the Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) in both Eastings 
and Northings were satisfactory. Thus, a RMSE value of 0.66 m and 0.96 m were 
obtained for the Eastings and Northings while 0.76 m and 0.73 m were the MAE values 
achieved. Also, the FV model attained a transformation accuracy of 0.49 m. Hence, this 
study will serve as a preliminary investigation in avoiding the use of height in 
coordinate transformation within Ghana’s geodetic reference network. 
 

Copyright © 2017 GJGP-UNDIP  
This open access article is distributed under a  

Creative Commons Attribution (CC-BY-NC-SA) 4.0 International license. 

How to cite (APA 6th Style): 
Ziggah, Y. Y, et al. (2017). Coordinate transformation using Featherstone and Vaníček proposed approach - a case study of Ghana geodetic reference 
network. Geoplanning: Journal of Geomatics and Planning, 4(1), 19-26. doi:10.14710/geoplanning.4.1.19-26 

 

1. INTRODUCTION  

The last decade has witnessed the ascendancy in the application of Global Navigation Satellite Systems 
(GNSS) for geospatial works in developed and developing countries. However, most developing countries 
like Ghana which is yet to migrate onto a geocentric datum cannot apply directly GNSS positional 
measurement without transforming the data into its local coordinate system. In line with this, several 
research works have been carried out to ascertain the applicability and capability of transformation 
methods such as three parameter, Bursa-Wolf, Molodensky-Badekas, Standard Molodensky, Iterative 
Abridged Molodensky, Veis, 3D projective, 12 parameter linear affine in Ghana geodetic reference network 
(Ayer & Fosu, 2008; Ayer & Tiennah, 2008; Ayer, 2008; Dzidefo, 2011; Poku-Gyamfi & Schueler, 2008; 
Ziggah et al., 2013a; Ziggah et al., 2013b). However, the general insight gathered from these studies in 
Ghana showed varying coordinate transformation results and accuracy among the various authors even 
though the same dataset is utilized. Upon careful observation, it is noticed that this phenomenon of 
inconsistencies in the results could mainly be attributed to the estimated local geodetic height used in the 
coordinate transformation process. This is because the iterative Abridged Molodensky technique utilized to 

Article Info: 
Received: 30 July 2016 
in revised form: 18 September 2016 
Accepted: 26 January 2017 
Available Online:  26 March 2017 
 

Keywords:  
Coordinate transformation, Global 
Navigation Satellite Systems, 
Geodetic Reference Network, 
Featherstone and Vaníček model 
 

Corresponding Author: 
Yao Yevenyo Ziggah  
Geomatic Engineering Department, 
Faculty of Mineral Resource 
Technology, University of Mines 
and Technology, Tarkwa, Western 
Region, Ghana 
Email: yyziggah@umat.edu.gh  

OPEN ACCESS 

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estimate the ellipsoidal height correction and in return used to estimate the ellipsoidal height is difficult to 
reach convergence for the ellipsoidal height correction factor. In so doing, researchers in Ghana applied 
different geodetic height correction values to estimate the local geodetic height thus obtaining different 
coordinate transformation results. It therefore confirms the assertion made by Dzidefo (2011) and Kotzev 
(2013) that there exist no ideal transformation parameters to be utilized in Ghana. Hence, this has 
contributed to the users’ adoption of different transformation parameters in the GNSS data processing in 
Ghana.  

It is important to note that the effect of height distortions in horizontal geodetic datum transformation 
has been duly investigated (Featherstone & Vanicek, 1999; Vaníček & Steeves, 1996). In order to minimize 
these distortions, Vaníček and Steeves (1996) proposed a four-parameter transformation model in which 
geodetic height in both global datum and local datum is not used and only three translations and one 
rotation parameter are needed to carry out coordinate transformation. Hence, the transformation 
parameters determined are free from geodetic height distortions. Similarly, Featherstone and Vanicek 
(1999) extended the four-parameter model to six-parameters on the premise that the orientation of the 
local geodetic system with respect to the geocentric system could possibly be done without using the local 
astronomic system at the origin of the network. The proposition thereof lies in coordinate transformation 
containing either four or six parameters. 

On the basis of the above related issues, the present authors were motivated to apply for the first time 
the Featherstone and Vanicek (1999) coordinate transformation model (FV model) in Ghana’s geodetic 
reference network. We deem it appropriate to apply such a method because Ghana’s national coordinate 
system is a two-dimensional projected grid coordinates. Applying the FV model will most importantly 
eliminate distortions related to the height component in the coordinate transformation of Ghana. This 
study will serve as guide on the importance of not using the local geodetic height since our national 
coordinate system is a two-dimensional projected grid coordinates. 

2. DATA AND METHODS 

A secondary data of 19 geodetic common point coordinates was acquired from the Ghana Survey and 
Mapping Division of Lands Commission. These data sets were in World Geodetic System 1984 (WGS84) and 
War Office 1926 ellipsoid. The War Office 1926 is the reference ellipsoid for Accra datum. The obtained 
data sets covered five out of ten regions in Ghana. These regions form the Ghana geodetic reference 
network known as the Golden Triangle. Figure 1 shows the study area and common point’s distribution. 

Figure 1. Area of study showing data distribution 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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2.1. Conversion of Geodetic Coordinate to Cartesian Coordinate 

The forward conversion of geodetic coordinate to Cartesian coordinate was the first step employed in 
the coordinate transformation process. To accomplish this task, the standard forward equation (Heiskanen 
& Moritz, 1967) defined in Equation (1) was used. 







sin]h)2e(1[NZ

sinλcosh)(NY

cosλcosh)(NX







     [1] 

where , λ and h  is the geodetic latitude, geodetic longitude and ellipsoidal height while X, Y, Z is the 

cartesian coordinates to be estimated. N in Equation (1) is the radius of curvature in the prime vertical 
defined by Equation (2) as 

22 sine1

a
N


       [2] 

 
Here, e is the first eccentricity expressed in Eq. (3) as 

a

2b2a
e


        [3] 

where a and b are the semi-major axis and semi-minor axis. 

On the basis of the concept proposed by Featherstone and Vanicek (1999); Vaníček and Steeves (1996) 
the heights for WGS84 and War Office 1926 should not be used. Hence, Equation (1) was modified into 
Equation (4) as 







)sin2eN(1Z

sinλNcosY

cosλNcosX







      [4] 

Equation (4) was then applied to convert all the 19 geodetic coordinates of common points designated 

in this study as WGS84λ),(  and Warλ),(  into cartesian coordinates. The transformed cartesian 

coordinates for WGS84 and War Office 1926 are represented in this study as (X, Y, Z)WGS84 and (X, Y, Z)War 

respectively. 

2.2. Coordinate using Featherstone and Vaníček (FV) Model 

The Featherstone and Vaníček (FV) model is a six parameter transformation that combines three 
rotation axis and three origin-shifts in a mathematical model which presents a relationship between points 
in two different Cartesian coordinate systems (Featherstone & Vanicek, 1999).  This study applied the FV 
model to determine three rotational and three translational parameters for transforming coordinates from 
global datum (WGS84) to Ghana local geodetic datum (War Office 1926). The FV model (Equation (5)) 
(Featherstone & Vanicek, 1999) could be represented mathematically as 

TRiMWGSQWarQ       [5] 

 
Here, QWar is the cartesian (X, Y, Z)War coordinates, QWGS is the cartesian (X, Y, Z)WGS84, M is a three-by-

three matrix containing each QWGS positions, R is the rotation matrix and T is the translation vector. M in 
Equation (5) is defined by Equation (6) as 

 

























0iXiY
iX0iZ

iYiZ0

M , i = 1,…,n     [6] 

 
where n is the number of observation points. Equation (5) could be rewritten in a simplified form expressed 
in Equation (7) as 

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PiAiΔQ:n1,i        [7] 

where  IM,iA   is the design matrix, I is the identity matrix, iΔQ is the observation vector and 

 tT,RP   is the transpose of the vector of the unknown transformation parameters to be determined. In 

this study, the least squares approach defined by Equation (8) was used to estimate the unknown 
parameters. 

ΔQ
1

ΔQCTA1A)
1

ΔQCT(AP


      [8] 

where AT is the transpose of the design matrix, 
WARQC

WGSQCΔQC  represent the sum of the 

variance covariance matrix of the cartesian coordinates of WGS84 and War Office 1926 system. 

2.3. Estimating New War Office Cartesian coordinates 

Here, the six transformation parameters calculated in Section 2.2 was used to transform the WGS84 
cartesian coordinates into the War Office 1926 system to obtain new War Office cartesian coordinates 
denoted as (Xnwar, Ynwar, Znwar). These coordinates were obtained by rewriting Equation (7) as Equation (9). 

P)*i(AWGSQWarQ       [9] 

 

2.4. Converting Cartesian Coordinates to Geodetic Coordinates 

The (Xnwar, Ynwar, Znwar) (Section 2.3) was converted into geodetic coordinates. This conversion was 
necessary so that the obtained geodetic coordinates could be projected on to the Transverse Mercator to 
obtain two-dimensional projected grid coordinates which is the national mapping coordinate system 
utilized for surveying and mapping purposes in Ghana. To achieve this, Paul’s method (Paul, 1973) was used 
in the reverse conversion. The choice of this method was based on a study carried out by Kumi-boateng 
and Ziggah (2016) where the Paul’s method performed slightly better than other six reverse conversion 
techniques evaluated for the Ghana geodetic reference network. In that respect, having (Xnwar, Ynwar, Znwar), 
the geodetic latitude ( ) was obtained using Equation (10) given as 

2

Z
ςptan                   [10] 

where 2Y2Xp  and 

1t4

Zα
1t

2

β

4

2Z
1tς  .  

To get ς , the variables ς),1t,1uq,β,,( should be calculated in an orderly manner using Equation (11) to 

(15) respectively. 

2e1

4e2a2p
α




                [11] 

2e1

4e2a2p
β




                [12] 

22

22

)Z2(β

β)(α27Z
1q




               [13] 












3 12qq3 12qq

2
1

1u                        [14] 

6

β

12

Z
u

6

2Zβ
t 













 
               [15] 

Detailed derivation of the Paul’s method can be found in Paul (1973). In this study, the conversion 

from ellipsoidal coordinates to plane coordinates (Transverse Mercator Projection); equations given in 

Dzidefo (2011) were used. 

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2.5. Accuracy Assessment 

The accuracy of the FV model utilised was analysed using statistical indices. This was done by 
quantifying the residuals obtained when the FV model results were subtracted from the existing projected 
grid coordinates. The statistical indices used are the root mean square error (RMSE), mean absolute error 
(MAE), horizontal position error (HE) and standard deviation (SD). They are defined by Equation (16) to (19) 
respectively as 

 
 n

1i
2)iPi(O

n

1
RMSE               [16] 





n

1i iPiO
n

1
MAE                  [17] 

2ΔN2ΔEHE                 [18] 








n

1i

2)e(e
1n

1
SD               [19] 

where n is the number of observations, Oi and Pi represents the existing projected grid coordinates and 

computed projected grid coordinates. e is the error between Oi and Pi with e as its mean. 

3. RESULTS AND DISCUSSION 

3.1. Transformation Parameters Determined 

Table 1 shows the transformation parameters and their related standard deviations for transforming 
coordinates from WGS84 (US Department of Defense, 1984) to War Office 1926 system using Featherstone 
and Vaníček (1999) model. With reference to Table 1, ΔX, ΔY, ΔZ is the translation parameters while Rx, Ry 
and Rz represent the rotational parameters. These translation parameters (Table 1) signify the degree of 
shift in origins of WGS84 and War Office 1926 along the three axes in three-dimension space. The 
rotational parameters around each of the X, Y and Z axes relate the orientation of the WGS84 and War 
Office 1926 systems. 

Table 1. Parameters from FV model 
Parameters Value 

ΔX (m) 164.585 ± 0.098 

ΔY (m) -4.781 ± 1.326 

ΔZ (m) -21.902 ± 1.003 

Rx (arc seconds) -1.613E-06 ± 1.180E-06 

Ry (arc seconds) -4.736E-05 ± 1.56E-07 

Rz (arc seconds) 4.335E-06 ± 1.55E-07 

 
3.2. Analysis of Transformed Coordinates Results 

The shifts in coordinates (∆E, ∆N) between the existing coordinates and transformed coordinates by 
Featherstone and Vaníček (1999) (FV model) are presented in Table 2. The SD values and HE for the control 
points are also shown. These results (Table 2) indicate the extent at which each of the transformed 
coordinates produced by the FV model varies with respect to the existing coordinates. Figure 2 gives an 
illustration on how the residuals generated oscillate along the ideal zero residual (horizontal line) with 
respect to the observation points. From Figure 2, a fairly consistent rise and fall was noticed for the Easting 
coordinates whereas a sharp rise and fall was observed for the Northing coordinates respectively.  

Overall analysis of Figure 2 indicates that the residuals in Northings were higher than the Eastings. 
These residuals incurred by the FV model clearly depict the limitation in most mathematical models that 
they could only produce results approximating the existing data. Although the height component was not 
applied in this transformation, the residuals obtained suggest that the FV model could not completely 
absorb the horizontal coordinate distortions mainly contributed by the astro-geodetic network (War Office 

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1926) system. These factors however, have contributed to the inability of the FV model to notice its 
potential of providing higher (sub-metre or even sub-centimetre) accuracy even though it is a rigorous 
model. Hence, the ideal condition of obtaining zero residuals could not be achieved in this study. In order 
to mitigate these residual effects, we are proposing that distortion modelling should be carried out after 
coordinate transformation in Ghana geodetic reference network. However, the fact still remains that the FV 
model will serve as a preliminary step that will facilitate a viable consensus in selecting applicable 
transformation parameters in Ghana. This could be achieved because the height component which has 
created such inconsistencies in the transformation results among researchers in Ghana is not applicable in 
the Featherstone and Vaníček (1999) model. 

 
Table 2. Deviation of Transformed Coordinates from Existing Coordinates 

Point ID ∆E ∆N HE 

1 0.20 0.56 0.59 

2 0.34 0.45 0.56 

3 0.25 -2.23 2.24 

4 0.67 1.15 1.33 

5 0.21 -0.93 0.95 

6 0.25 -0.74 0.78 

7 0.92 -0.84 1.25 

8 0.64 0.36 0.73 

9 0.79 0.23 0.82 

10 0.80 -0.43 0.91 

11 -0.36 -0.10 0.37 

12 -0.91 -0.50 1.04 

13 -0.04 1.74 1.74 

14 -1.08 1.22 1.63 

15 0.45 0.76 0.88 

16 -0.85 0.99 1.30 

17 -0.62 -0.47 0.78 

18 -0.56 0.00 0.56 

19 -1.08 -1.24 1.64 

SD 0.68 0.98 0.49 

 

Figure 2. Residuals in Easting and Northing Coordinates 
 

 

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In order to ascertain the horizontal positional accuracy of the transformed coordinates this study 

applied Equation (18). The obtained estimated HE values (Table 2) show that a maximum horizontal 
uncertainty of 2.24 m was observed for Point 3. This high HE value for Point 3 was mostly contributed by 
the Northing coordinate which had an error of -2.23 m while an error of 0.25 m was gotten for Easting. 
Hence, because the HE is dependent on both values to get its estimates the value for Point 3 became 
higher. Nonetheless, this could be attributed to observational error or the point is located in a mountainous 
region. The FV model produced 0.374 m as the minimum HE. A graphical illustration of the HE (Table 2) is 
shown in Figure 3. The SD value of 0.49 m (Table 2) realised for HE indicate the transformation accuracy of 
the FV model utilised. 

Figure 3. Horizontal errors of the transformed coordinates 
 

 
 

The validity of the FV model was further assessed using the RMSE, MAE and SD respectively. In relation 

to the RMSE (Table 3), 0.66 m and 0.96 m were obtained for the Easting and Northing coordinates. These 

RMSE values quantify how close the FV model transformed coordinates differs from the observed data. 

That is, the FV model deviates from the most probable value (zero) by not more than 0.66 m and 0.96 m in 

Eastings and Northings respectively. Moreover, the MAE (Table 3) in Eastings and Northings were 0.58 m 

and 0.79 m respectively. This gives an indication on the magnitude of how close the FV model transformed 

coordinates is to the existing coordinates on average. The SD values (Table 3) for the coordinate differences 

in Easting and Northing show how wide the transformed coordinates are dispersed from the most probable 

value. Hence, signifying the precision of the data used. 

Table 3. Model Performance Assessment 

Statistical Indicators Eastings (m) Northings (m) 

RMSE 0.66 0.96 

MAE 0.76 0.73 

SD 0.68 0.98 

 

4. CONCLUSION 

Coordinate transformation is an active research area especially in countries that still use astro-geodetic 

datum for their surveying and mapping purposes. It is well understood that astro-geodetic networks were 

established as a horizontal datum based on local astronomical coordinates and thus lacked ellipsoidal 

height. However, in Ghana most coordinate transformation has been done by including height estimated 

using the Abridged Molodensky model to the horizontal positions (latitude and longitude). Conversely, this 

estimated height for the non-geocentric datum is irrelevant in horizontal geodetic datum transformation. 

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Rather, the height introduces more distortions into the local geodetic network. For the purpose of avoiding 

the use of height in coordinate transformation process, this study applied Featherstone and Vaníček model 

for the first time in Ghana geodetic reference network. The results revealed a RMSE error of 0.66 m and 

0.96 m in the Eastings and Northings with their corresponding MAE values at 0.76 m and 0.73 m 

respectively. A transformation accuracy of 0.49 m realised by the FV model showed that it could be utilized 

to transform coordinate in Ghana geodetic reference network. 

In line with the results, it was noticed that although the height component was not used in the 
transformation process the residuals produced between the existing and some FV transformed coordinates 
were high. The conclusion drawn here was that Ghana geodetic network is highly inherent with distortions 
that could not be more absorbed by the FV model. Hence, we agree with Featherstone and Vaníček (1999) 
that distortion modelling should be carried out right after transformation is done. This will help improve 
the coordinate transformation results because most distortions will be modelled out. Hence, for future 
studies in Ghana, we recommend that the distortion modelling should be adopted as part of the 
transformation process. 

5. ACKNOWLEDGMENT 

The authors would like to thank the anonymous reviewers for their time and effort to improve the 
quality of this paper. Our sincere appreciation also goes to the Ghana Survey and Mapping Division of Lands 
Commission for providing us with the necessary data set. 

6. REFERENCES 

Ayer, J. (2008). Transformation models and Procedures for Framework Integration of the Ghana National 
Geodetic Network. The Ghana Surveyor, 1(2), 52–58. 

Ayer, J., & Fosu, C. (2008). Map Coordinate Referencing and the use of GPS Datasets in Ghana. Journal of 
Science and Technology (Ghana), 28(1). [CrossRef] 

Ayer, J., & Tiennah, T. (2008). Datum transformation by the iterative solution of the abridging inverse 
Molodensky formulae. The Ghana Surveyor, 1(2), 59–66. 

Dzidefo, A. (2011). Determination of transformation parameters between the World Geodetic System 1984 
and the Ghana geodetic network. Kwame Nkrumah University of Science & Technology. Retrieved 
from http://ir.knust.edu.gh/bitstream/123456789/298/1/THESIS.pdf  

Featherstone, W., & Vanicek, P. (1999). The role of coordinate systems, coordinates and heights in 
horizontal datum transformations. Australian Surveyor, 44(2), 143–150. [CrossRef] 

Heiskanen, W. A., & Moritz, H. (1967). Physical geodesy. Bulletin Géodésique (1946-1975), 86(1), 491–492. 
Kotzev, V. (2013). Consultancy service for the selection of a new projection system for Ghana. Draft Final 

Reports, World Bank Second Land Administration Project (LAP-2), Ghana. 
Kumi-boateng, B., & Ziggah, Y. Y. (2016). Accuracy Assessment of Cartesian ( X , Y , Z ) to Geodetic 

Coordinates ( φ , λ , h ) Transformation Procedures in Precise 3D Coordinate Transformation – A Case 
Study of Ghana Geodetic Reference Network. Journal of Geosciences and Geomatics, 4(1), 1–7. 
[CrossRef]  

Paul, M. K. (1973). A note on computation of Geodetic coordinates from geocentric (Cartesian) coordinates. 
Bulletin Géodésique (1946-1975), 108(1), 135–139. [CrossRef]  

Poku-Gyamfi, Y., & Schueler, T. (2008). Renewal of Ghana’s geodetic reference network. In 13th FIG 
Symposium on Deformation Measurement and Analysis, 4th IAG Symposium on Geodesy for 
Geotechnical and Structural Engineering, LNEC, LISBON (pp. 1–9). 

US Department of Defense. (1984). World Geodetic System 1984 (WGS84). 
Vaníček, P., & Steeves, R. R. (1996). Transformation of coordinates between two horizontal geodetic 

datums. Journal of Geodesy, 70(11), 740–745. [CrossRef]   
Ziggah, Y. Y., et al. (2013a). Determination of GPS coordinate transformation parameters of geodetic data 

between reference datums—a case study of ghana geodetic reference network. International Journal 
of Engineering Sciences and Research Technology, 2(4), 965–971. 

Ziggah, Y. Y., et al. (2013b). Accuracy Assessment of Centroid Computation Methods in Precise GPS 
Coordinates Transformation Parameters Determination-A Case Study, Ghana. European Scientific 
Journal, 9(15), 200–220. 

http://dx.doi.org/10.14710/geoplanning.4.1.19-26
https://doi.org/10.4314/just.v28i1.33084
http://ir.knust.edu.gh/bitstream/123456789/298/1/THESIS.pdf
https://doi.org/10.1080/00050326.1999.10441920
https://doi.org/10.12691/jgg-4-1-1
https://doi.org/10.1007/BF02522075
https://doi.org/10.1007/BF00867152

