scholarly journals Error analysis and accuracy assessment of GPS absolute velocity determination without SA

2008 ◽  
Vol 11 (2) ◽  
pp. 133-138 ◽  
Author(s):  
Fuhong Wang ◽  
Xiaohong Zhang ◽  
Jingsong Huang
2021 ◽  
Vol 16 (2) ◽  
pp. 162-174
Author(s):  
Sharir Aizat Kamaruddin ◽  
Khairul Naim Abd. Aziz ◽  
Muhammad Akmal Roslani ◽  
Zamzila Erdawati Zainol

The purpose of this research is to evaluate the precision of the Inverse Distance Weighted (IDW) to estimate and map the coastal water pH for the sustainability of Pulau Tuba, Langkawi, Kedah. 30 sampling points have been set up during two sampling activities in November 2018. The pH meter has been calibrated and lowered to 1 meter below the water surface to measure the reading of pH. The development of the spatial model was developed using the spatial analyst tool available in ArcGIS Software. Several types of statistical analyses were carried to compare the observed and predicted value of pHs such as correlation analysis, regression analysis, and error analysis. Accuracy assessment was carried later after the transformation of a spatial model into a surface map. The research found that the IDW method successfully interpolated the pH readings. The research found that there is a strong positive correlation between the observed and predicted values. For error analysis, Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) were recorded at 0.033 and 0.044, respectively. After the transformation of the spatial model to the surface map, the accuracy of the map is recorded at 81.25%. The map produced can be used by residents and local government for social and economic development and protection of biodiversity at the coastal water of Pulau Tuba, Langkawi, Kedah.


2015 ◽  
Vol 7 (1) ◽  
pp. 485-495 ◽  
Author(s):  
Shouzhi Xu ◽  
Pengfei Cheng ◽  
Yu Zhang ◽  
Penghui Ding

2020 ◽  
Vol 12 (12) ◽  
pp. 1974 ◽  
Author(s):  
Minsu Kim ◽  
Seonkyung Park ◽  
Jeffrey Irwin ◽  
Collin McCormick ◽  
Jeffrey Danielson ◽  
...  

The Leica Geosystems CountryMapper hybrid system has the potential to collect data that satisfy the U.S. Geological Survey (USGS) National Geospatial Program (NGP) and 3D Elevation Program (3DEP) and the U.S. Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) requirements in a single collection. This research will help 3DEP determine if this sensor has the potential to meet current and future 3DEP topographic lidar collection requirements. We performed an accuracy analysis and assessment on the lidar point cloud produced from CountryMapper. The boresighting calibration and co-registration by georeferencing correction based on ground control points are assumed to be performed by the data provider. The scope of the accuracy assessment is to apply the following variety of ways to measure the accuracy of the delivered point cloud to obtain the error statistics. Intraswath uncertainty from a flat surface was computed to evaluate the point cloud precision. Intraswath difference between opposite scan directions and the interswath overlap difference were evaluated to find boresighting or any systematic errors. Absolute vertical accuracy over vegetated and non-vegetated areas were also assessed. Both horizontal and vertical absolute errors were assessed using the 3D absolute error analysis methodology of comparing conjugate points derived from geometric features. A three-plane feature makes a single unique intersection point. Intersection points were computed from ground-based lidar and airborne lidar point clouds for comparison. The difference between two intersection points form one error vector. The geometric feature-based error analysis was applied to intraswath, interswath, and absolute error analysis. The CountryMapper pilot data appear to satisfy the accuracy requirements suggested by the USGS lidar specification, based upon the error analysis results. The focus of this research was to demonstrate various conventional accuracy measures and novel 3D accuracy techniques using two different error computation methods on the CountryMapper airborne lidar point cloud.


1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.


1995 ◽  
Vol 11 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Dietmar Heubrock

Performance on a German version of the Rey Auditory-Verbal Learning Test (AVLT) was investigated for 64 juvenile patients who were subdivided in 6 clinical groups. In addition to standard evaluation of AVLT protocols which is usually confined to items recalled correctly, an error analysis was performed. Differentiating between total errors (TE), repetition errors (RE), and misnamings (ME), substantial differences between clinical groups could be demonstrated. It is argued that error analysis of verbal memory and learning enriches the understanding of neuropsychological syndromes, and provides additional information for diagnostic and clinical use. Thus, it is possible to gain a more accurate picture so that patients can be appropriately retrained, and research into the functional causes of memory and learning disorders can be intensified.


1994 ◽  
Vol 4 (10) ◽  
pp. 1999-2012 ◽  
Author(s):  
Nabil Derbel ◽  
Mohamed B.A. Kamoun ◽  
Michel Poloujadoff

2020 ◽  
Vol 52 ◽  
pp. 55-61
Author(s):  
Ettore Potente ◽  
Cosimo Cagnazzo ◽  
Alessandro Deodati ◽  
Giuseppe Mastronuzzi

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