For quality assurance purposes the generated map is visually compared to 5 m and 20 m contour intervals of standard topographic maps (1:50000) issued by the Chief Directorate Surveys and Mapping (CDSM). The operation can be performed as following: points and values of "0" for the Z coordinate. (15) In this research was made a study in a space of SC-414 highway with the objective of studying applications for photogrammetric products, of the Laser Scanner sensor and integration of both in highway projects. One of the important requirements of users for these surveying instruments - the accuracy of the measurement, which determines the accuracy of determining the coordinates of the turning points and the land area.

The coordinates of the interested points were. The statistical analysis has supported these results where the value of the Standard Deviation (SD) of the DEM has increased with increasing the power.

Why is "hand recount" better than "computer rescan"? This work marks the first instance of the extensive use of Google Earth as a tool in mapping and determining the kinematics of active faults. Distance calculations could be much less accurate than that. The two, steps were repeated until surveying all reference points and recording the surveyed points for, All data obtained from the field was downloaded into computer using the capabilities of, the available software with the total station.

The DEM from the sampled points for each region was created using Surfer Software, (Golden Software, 2012) to establish comparison consistency. The collection of information on case study area was performed in two steps.

Presently, the quality of readily available elevation data varies by source and acquisition technology., Thus, under some circumstances, Google Earth elevation data may be inaccurate where a roadway is under an overhead structure or a roadway is within a tunnel. Can you add a link to the page where you found the official stance? Overall, it is found that the high accuracy elevation data available from GE provide a reliable data source for various transportation applications. Moreover, the higher the piercing points and the higher the elevation difference between two piercing points, the higher the error will be. For testing, a freeway segment with different subgrade elevation on the two directions is selected as shown in Fig 8(a). (7) However, Google Earth improved the results by using (in house) interpolation algorithms to mix and mesh SRTM data with other data in order to derive accurate results for these area. In general, Google Earth elevation data can be used only for investigation and preliminary studies with low cost. With more than 200 million downloads since its release in June 2005 [15], Google Earth (GE) has recently been recognized for its potential to significantly improve the visualization and dissemination of scientific data [16–18].

The horizontal positional accuracy of Google Earth is assessed in the city of Montreal, Canada, using the precise coordinates of ten GPS points spatially distributed all over the city. The obtained accuracies for terrain with small height difference can be used for preparing large area cadastral, city planning, or land classification maps. 5 Howick Place | London | SW1P 1WG. The technological development made possible the appearance of complemental sensor to the photogrammetric cameras as the Laser Scanner sensor. To test the performance of multi-layered roadway recognition method, we chose the Interstate Freeway No.5 southbound in the downtown area of Portland, OR, which contains 17 overlapping segments including interchanges and a double layer bridge. Yes This same path line has disappeared from view and isn't showing on the map. Golden Software, Inc., It only takes a minute to sign up. These are provided for entertainment only and should not be used for any navigational or other purpose requiring any accuracy whatsoever". Finally, all 3 contour maps were compared to a contour map of 0.5 m-interval resolution specifically generated for the study area using aerial photography from an airborne survey. lisadoc Well-Known Member. The results revealed a strong relationship between the reference DEM and the aerial photo DEM, and it is found that there is a moderate relationship between the reference DEM and the Shuttle Radar Topography Mission (SRTM), GE, and ASTER GDEM 2 DEMs. Currently available datasets include the global 30 arc-second elevation (GTOPO30) dataset [9], elevation dataset from Shuttle Radar Topography Mission (SRTM) [10], National Elevation Dataset from the U.S. Geological Survey (USGS NED) [11], Global Digital Elevation Model (GDEM) [12], and Light Detection and Ranging (LIDAR) [13] elevation datasets. Hopes are raised with the advent of satellite derived Digital Elevation datasets or dataset. The longitude and latitude of the starting and ending points for each direction at the roadway centerline are input into the coordinate transformation method., Large area cadastral, city planning, or land classification maps are typically in. In general, lowerlying The reference data was collected with total station survey. Δφi,i-1 indicates the slope angle difference between rolling space interval i and its previous one. Most of the USGS NED data for Alaska are available at a 2-arc-second (about 60 meters) grid spacing because only lower resolution source data exist there. exported to an ASCII file for post processing application. and P.B.S. Register to receive personalised research and resources by email, Assessing horizontal positional accuracy of Google Earth imagery in the city of Montreal, Canada, École de technologie supérieure (ÉTS), Laboratory of Space technologies, Embedded System, Navigation and Avionics (LASSENA), 1100 rue Notre Dame Ouest, Montreal (QC), H3C 1K3, Canada, /doi/pdf/10.3846/20296991.2017.1330767?needAccess=true. Press, London, UK. However, it still needs to be converted into more reliable and accurate data by combining with pre-processing tools. Was really just looking for any sort of information on it.

2, 2015 from Three interstate freeways and five state highways are involved in this assessment. The next stage consisted of Laser Scanner point cloud treatment, using for that programs CAD and specific programs for work of data laser.

After just installing a break water and knowing all the dimensions, i checked it on google earth to see how close the eye in the sky is, on 470 ft it showed 477 ft, I tried google earth pro it did not make a difference. 8 years have passed, so now the data accuracy can only improved. 0.1√Kfor ordinary and rough levelling (respectively)basicrequirements/standard.On the ASPRS accuracy standards for large-scale maps. The results obtained for each state shown in Table 2 indicate that the accuracy of GE elevation along the roadway does not vary significantly by location (states). The accuracy of the Google earth derived elevation data are reported using root mean square error (RMSE), mean error (ME) and maximum absolute error (MAE). This means that sufficiently detailed relief information is often difficult to obtain for wetland research.

The, accuracy of the Google earth derived elevation data are reported using root mean square error, (RMSE), mean error (ME) and maximum absolute erro, were computed using the ground coordinates of 200 reference points for each region of the, case study. Also, the. entrance of Kuwait Bay, which is located on the north-western side of The point of origin of each UTM zone is the intersection of the, The transformation formulas are truncated version of Transverse Mercator: flattening, series, which were described in Bomford, 1977. A comprehensive accuracy assessment of the GE-extracted elevation data is conducted for the area of conterminous USA. 51608386), and Shanghai Sailing Program (grant no. Two datasets are utilized as ground truth data to examine the accuracy of the elevation data extracted from the GE. From 2004, the survey and the GIS have been extended to the western and northern parts of the necropolis, at the moment counting more than 2,000 mapped and recorded tombs. In this paper, the accuracy of Google Earth (G.E.) However, making correlations between field survey and GE can provide 95% fitness, and also, subtracting the acquired RMSE for the vertical case from the original Google Earth elevation data can provide a 90% fitness for preparing class-1 map as well. Moreover, the accuracies in elevations while using different digital elevation model scenarios and their respective impacts for water distribution network modeling were also evaluated. Azeez (2005). The acquired horizontal RMSE of Google Earth was found fit to produce a class-1 map of having 1:20,000 scale as recommended by ASPRS-1990. Based on these results they concluded that you can use Google Earth as a good source for mapping in scales smaller than 1:150000, assuming the planimetrical error as 0,1 mm. In the menu bar, click Tools Ruler. Moreover, DEMs are used often in geographic information systems (GIS), and are the most common basis for digitally-produced relief maps. El-Ashmawy, K., and A.B. where Lk is the length of segment k, gk is the grade of segment k, and ϕj is the slope angle at sampling point j in segment k. With the extraction method proposed in this study, the applicability of the GE elevation for transportation applications depends on the accuracy of the original GE elevation data. The governmental plans are to develop the islands, which will be The studies were conducted at a specialized reference geodetic network, authorized to carry out such tests, and is a benchmark tool for metrological certification of surveying instruments. (14)

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. 3rd edition, Oxford Univ. Coastal Vulnerability Index (CVI) was computed The mean elevation among three groups has no statistic difference (F = 1.536, P = 0.215). Discussions on data reliability, inconsistencies with NAPA survey results, and alternative approaches to utilizing the oversupply of RAP will also be presented. 53-68.

The precision of GE elevation data along roadways is satisfactory, and there is no evidence showing the accuracy of GE roadway elevation varies significantly between states or route types; and. In this study, the Haversine-formula [20] has been used in the distance calculation function f to improve numerical stability: However, subtracting the acquired RMSE for the vertical case from the original Google Earth elevation data’s can provide a 90% fitness for preparing class-1 map as well and 95% could be achieved by applying the computed correlation coefficient. Schistosomiasis japonicum is a major zoonosis that seriously harms human health and affects social and economic development in China. Generation of Mathematical Digital Terrain Model. Out of the different methods of, grid interpolation of Surfer software, Kriging method is recommended (El-Ashmawy and, Azeez, 2005) and used in this research.