scholarly journals Some Equal-area, Conformal and Conventional Map Projections: A Tutorial Review

2016 ◽  
Vol 10 (3) ◽  
Author(s):  
Ebrahim Ghaderpour

AbstractMap projections have been widely used in many areas such as geography, oceanography, meteorology, geology, geodesy, photogrammetry and global positioning systems. Understanding different types of map projections is very crucial in these areas. This paper presents a tutorial review of various types of current map projections such as equal-area, conformal and conventional. We present these map projections from a model of the Earth to a flat sheet of paper or map and derive the plotting equations for them in detail. The first fundamental form and the Gaussian fundamental quantities are defined and applied to obtain the plotting equations and distortions in length, shape and size for some of these map projections.

2021 ◽  
Vol 21 (1) ◽  
pp. 1-10
Author(s):  
S. Mantey ◽  
M. S. Aduah

Mining operations involve the extraction of minerals of economic value from the earth. In surface mining operations, overburdens need to be stripped in other to reach the ore. Large volumes of waste as well as ore is stripped in the process. Various technologies have been used to aid in stockpile volume estimation. Notable among them are the Total Stations and Global Positioning Systems (GPS). However, labour, safety and time has challenged the use of these technologies. Unmanned Aerial Vehicle (UAV), commonly known as drone is an emerging technology for stockpile volume computations in the Mine. UAV technology for data collection is less labour intensive, safer and faster. Therefore, this study applied the UAV technology in an open pit to estimate stockpile volumes from a Mine. For the purpose of this study, GPS and UAV data were collected for measuring stockpile volumes of materials mined. The actual volumes of stockpiles A, B, C, D (Case 2), produced differences of 0.05% for A, 0.05% for B, 0.08% for C, 0.07% for D and 0.03% for A, -0.03% for B, 0.03% for C and 0.04% for D, for the GPS-based and the UAV-based techniques, respectively. The GPS-based technique generated moderate accuracies for volume estimation, but was time consuming and labour intensive, compared to the UAV-based technique; which was faster and less labour intensive. The UAV-based technique was the most accurate, safest and is capable of mapping large areas rapidly. It is therefore recommended that UAV survey be incorporated in stockpile volume estimation. Keywords: UAV, GPS, Stockpile, Mine, Total Stations


2012 ◽  
Vol 2 (3 - 4) ◽  
pp. 117
Author(s):  
Jeison Daniel Salazar Pachón ◽  
David Armando Chaparro Obando ◽  
Nicolás Tordi

<p>El presente estudio examinó  la confiabilidad de los registros de dos sistemas de posicionamiento global (<em>global positioning systems  </em>[GPS]), Garmin310XT y FRWDB600,  sobre  las distancias  recorridas a diferentes  velocidades,  tras un protocolo a pie y otro  en bicicleta realizados  en una pista atlética.  Esta información se comparó con el trayecto  real de recorrido, hecho a partir  del cálculo: <em>ritmo de recorrido (r) = distancia recorrida (d) x tiempo  de recorri- do, </em>y se controló con un metrónomo Sport Beeper. Los participantes fueron dos jóvenes de edad  media  22 años  ± 1, activos  físicamente. En los resultados, se observaron diferencias  entre los registros de ambos sistemas GPS; el protocolo a pie Garmin tuvo un porcentaje de concordancia de 101,1%, mientras que FRWD presentó  103%. En el protocolo en bicicleta se obtuvo 103,4% y 101,6%, respectivamente. Se concluyó  que el uso de GPS es más fiable cuando  las velocidades  de desplazamiento humano son bajas  o moderadas  para  el sistema Garmin  (7-14 km/h), ya que al ser más altas la fiabilidad  de la información podría  ser menor, mientras  que el sistema FRWD presentó  mayor confiabilidad en velocidades moderadas (14-22 km/h).</p>


2011 ◽  
Vol 1 (2) ◽  
pp. 117
Author(s):  
Jeison Daniel Salazar Pachón ◽  
David Armando Chaparro Obando ◽  
Nicolás Tordi

El presente estudio examinó  la confiabilidad de los registros de dos sistemas de posicionamiento global (<em>global positioning systems  </em>[GPS]), Garmin310XT y FRWDB600,  sobre  las distancias  recorridas a diferentes  velocidades,  tras un protocolo a pie y otro  en bicicleta realizados  en una pista atlética.  Esta información se comparó con el trayecto  real de recorrido, hecho a partir  del cálculo: <em>ritmo de recorrido (r) = distancia recorrida (d) x tiempo  de recorrido, </em>y se controló con un metrónomo Sport Beeper. Los participantes fueron dos jóvenes de edad  media  22 años  ± 1, activos  físicamente. En los resultados, se observaron diferencias  entre los registros de ambos sistemas GPS; el protocolo a pie Garmin tuvo un porcentaje de concordancia de 101,1%, mientras  que FRWD presentó  103%. En el protocolo en bicicleta se obtuvo 103,4% y 101,6%, respectivamente. Se concluyó  que el uso de GPS es más fiable cuando  las velocidades  de desplazamiento humano son bajas  o mo- deradas  para  el sistema Garmin  (7-14 km/h), ya que al ser más altas la fiabilidad  de la información podría  ser menor, mientras  que el sistema FRWD presentó  mayor confiabilidad en velocidades moderadas (14-22 km/h).


Author(s):  
Jason Scully ◽  
Anne Moudon ◽  
Philip Hurvitz ◽  
Anju Aggarwal ◽  
Adam Drewnowski

Exposure to food environments has mainly been limited to counting food outlets near participants’ homes. This study considers food environment exposures in time and space using global positioning systems (GPS) records and fast food restaurants (FFRs) as the environment of interest. Data came from 412 participants (median participant age of 45) in the Seattle Obesity Study II who completed a survey, wore GPS receivers, and filled out travel logs for seven days. FFR locations were obtained from Public Health Seattle King County and geocoded. Exposure was conceptualized as contact between stressors (FFRs) and receptors (participants’ mobility records from GPS data) using four proximities: 21 m, 100 m, 500 m, and ½ mile. Measures included count of proximal FFRs, time duration in proximity to ≥1 FFR, and time duration in proximity to FFRs weighted by FFR counts. Self-reported exposures (FFR visits) were excluded from these measures. Logistic regressions tested associations between one or more reported FFR visits and the three exposure measures at the four proximities. Time spent in proximity to an FFR was associated with significantly higher odds of FFR visits at all proximities. Weighted duration also showed positive associations with FFR visits at 21-m and 100-m proximities. FFR counts were not associated with FFR visits. Duration of exposure helps measure the relationship between the food environment, mobility patterns, and health behaviors. The stronger associations between exposure and outcome found at closer proximities (<100 m) need further research.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 798
Author(s):  
Hamed Darbandi ◽  
Filipe Serra Bragança ◽  
Berend Jan van der Zwaag ◽  
John Voskamp ◽  
Annik Imogen Gmel ◽  
...  

Speed is an essential parameter in biomechanical analysis and general locomotion research. It is possible to estimate the speed using global positioning systems (GPS) or inertial measurement units (IMUs). However, GPS requires a consistent signal connection to satellites, and errors accumulate during IMU signals integration. In an attempt to overcome these issues, we have investigated the possibility of estimating the horse speed by developing machine learning (ML) models using the signals from seven body-mounted IMUs. Since motion patterns extracted from IMU signals are different between breeds and gaits, we trained the models based on data from 40 Icelandic and Franches-Montagnes horses during walk, trot, tölt, pace, and canter. In addition, we studied the estimation accuracy between IMU locations on the body (sacrum, withers, head, and limbs). The models were evaluated per gait and were compared between ML algorithms and IMU location. The model yielded the highest estimation accuracy of speed (RMSE = 0.25 m/s) within equine and most of human speed estimation literature. In conclusion, highly accurate horse speed estimation models, independent of IMU(s) location on-body and gait, were developed using ML.


2021 ◽  
Vol 9 (4) ◽  
pp. 410
Author(s):  
Fan Zhang ◽  
Xin Peng ◽  
Liang Huang ◽  
Man Zhu ◽  
Yuanqiao Wen ◽  
...  

In this study, a method for dynamically establishing ship domain in inland waters is proposed to help make decisions about ship collision avoidance. The surrounding waters of the target ship are divided to grids and then calculating the grid densities of ships in each moment to determine the shape and size of ship domain of different types of ships. At last, based on the spatiotemporal statistical method, the characteristics of ship domains of different types of ship in different navigational environments were analyzed. The proposed method is applied to establish ship domains of different types of ship in Wuhan section of the Yangtze River in January, February, July, and August in 2014. The results show that the size of ship domain increases as the ship size increases in each month. The domain size is significantly influenced by the water level, and the ship domain size in dry seasons is larger than in the wet seasons of inland waters.


Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 479
Author(s):  
Irina Sokolik

This Special Issue aims at addressing the recent developments towards improving our understanding of the diverse radiative impact of different types of aerosols and clouds [...]


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