scholarly journals Mapping underground infrastructure using photogrammetric methods

2021 ◽  
Author(s):  
Mark K. Tulloch

Underground infrastructure mapping in many urban areas lacks the necessary accuracy and detail required to conduct underground construction. This is a result of inadequate surveying methodologies and poor historical as-built records. One solution to this problem is the development of a mobile terrestrial photogrammetric mapping system to expose utilities on construction sites. This thesis outlines the design of the Underground Infrastructure Mapping System (UIMS). The system is comprised of three pieces of hardware including a tablet PC, a Global Positioning System (GPS) receiver, and a digital camera. Results indicte that the UIMS has an absolute spatial accuracy of 28 cm (within the City of Toronto) and a relative accuracy of 13 cm (95% confidence level). The data collection time per exposed utility feature is approximtely ten minutes on site, and an additional five minutes of post-processing. The cost of the system's hardware is under $5000.

2021 ◽  
Author(s):  
Mark K. Tulloch

Underground infrastructure mapping in many urban areas lacks the necessary accuracy and detail required to conduct underground construction. This is a result of inadequate surveying methodologies and poor historical as-built records. One solution to this problem is the development of a mobile terrestrial photogrammetric mapping system to expose utilities on construction sites. This thesis outlines the design of the Underground Infrastructure Mapping System (UIMS). The system is comprised of three pieces of hardware including a tablet PC, a Global Positioning System (GPS) receiver, and a digital camera. Results indicte that the UIMS has an absolute spatial accuracy of 28 cm (within the City of Toronto) and a relative accuracy of 13 cm (95% confidence level). The data collection time per exposed utility feature is approximtely ten minutes on site, and an additional five minutes of post-processing. The cost of the system's hardware is under $5000.


2021 ◽  
Vol 10 (4) ◽  
pp. 230
Author(s):  
Onel Pérez-Fernández ◽  
Juan Carlos García-Palomares

Moped-style scooters are one of the most popular systems of micro-mobility. They are undoubtedly good for the city, as they promote forms of environmentally-friendly mobility, in which flexibility helps prevent traffic build-up in the urban centers where they operate. However, their increasing numbers are also generating conflicts as a result of the bad behavior of users, their unwarranted use in public spaces, and above all their parking. This paper proposes a methodology for finding parking spaces for shared motorcycle services using Geographic information system (GIS) location-allocation models and Global Positioning System (GPS) data. We used the center of Madrid and data from the company Muving (one of the city’s main operators) for our case study. As well as finding the location of parking spaces for motorbikes, our analysis examines how the varying distribution of demand over the course of the day affects the demand allocated to parking spaces. The results demonstrate how reserving a relatively small number of parking spaces for scooters makes it possible to capture over 70% of journeys in the catchment area. The daily variations in the distribution of demand slightly reduce the efficiency of the network of parking spaces in the morning and increase it at night, when demand is strongly focused on the most central areas.


2011 ◽  
Vol 64 (S1) ◽  
pp. S151-S161 ◽  
Author(s):  
Sihao Zhao ◽  
Mingquan Lu ◽  
Zhenming Feng

A number of methods have been developed to enhance the robustness of Global Positioning System (GPS) receivers when there are a limited number of visible satellites. Vector tracking is one of them. It utilizes information from all channels to aid the processing of individual channels to generate receiver positions and velocities. This paper analyzes relationships among code phase, carrier frequency, and receiver position and velocity, and presents a vector loop-tracking algorithm using an Extended Kalman filter implemented in a Matlab-based GPS software receiver. Simulated GPS signals are generated to test the proposed vector tracking method. The results show that when some of the satellites are blocked, the vector tracking loop provides better carrier frequency tracking results for the blocked signals and produces more accurate navigation solutions compared with traditional scalar tracking loops.


2019 ◽  
Vol 21 (2) ◽  
pp. 1363-1373
Author(s):  
Gabriella Saraiva de Albuquerque ◽  
Mirelle Oliveira Silva ◽  
Gabriela De Souza Estevão

O presente trabalho, está vinculado a um projeto de iniciação científica desenvolvido junto ao Laboratório de Geoprocessamento da Universidade Regional do Cariri que tem como temática a modelagem espacial das ilhas de calor e de frescor na cidade de Juazeiro do Norte, Ceará, Brasil. Os resultados apresentados foram obtidos através do primeiro campo do referido projeto de pesquisa e foi realizado por meio da metodologia de transecto móvel, contemplando os trajetos na direção sul-norte e oeste-leste para a coleta dos dados de temperatura do ar, com o intuito de compreender os contrastes térmicos da cidade de Juazeiro do Norte. O transecto fora realizado ainda no período chuvoso e iniciou-se às 21:00 horas, não ultrapassando 50 minutos, coletando no total a temperatura de 25  pontos distribuídos no perímetro urbano e considerando as características geoeambientais e geourbanas. Os registros foram executados utilizando um termômetro digital com sensor externo com cabo de 2m Icotem e um receptor GPS (Global Positioning System) modelo Garmin Map 76CSX para marcação das coordenadas UTM dos respectivos registros de temperatura. As maiores temperaturas, de 24,8ºC á 25,8ºC foram registradas em espaços densamente construídos, as menores, entre 22,6ºC á 23ºC foram percebidas em áreas com características rurais e menos urbanizadas.Palavras-chave: Ilha de calor. Clima urbano. Transecto Móvel.                                                                   ABSTRACTThe present work is linked to a project of scientific initiation, together with the Laboratory of Geoprocessing of the Regional University of Cariri, whose theme is the spatial modeling of the islands of heat and freshness in the city of Juazeiro do Norte, Ceará, Brazil. The results of the research were submitted through the mapping of the first study plan south-north and east-east to the collection of data of air temperature, with the intention. Of contracting the thermal contrasts of the city of Juazeiro of the North. The transectofor theater was still rainy and began at 21:00 hours, not exceeding 50 minutes, collecting in total the temperature of 25 points distributed in the urban perimeter and considering geo-environmental and georban features. The terminals were run using a digital thermometer with external sensor with 2m Icotem cable and a GPS (Global Positioning System) receiver model Garmin Map 76CSX for marking the UTM coordinates of the children temperature registers. The highest temperatures, from 24.8ºC to 25.8ºC were recorded in densely constructed spaces, the lowest temperatures, between 22.6ºC and 23ºC, were observed in areas with rural and less urbanized characteristics.Keywords: Island of heat. Urban climate. Transect Mobile. RESUMENEste trabajo está vinculado a un proyecto de iniciación científica desarrollado en el Laboratorio de Geoprocesamiento de la Universidad Regional de Cariri, cuyo tema es el modelado espacial de las islas de calor y frescura en la ciudad de Juazeiro do Norte, Ceará, Brasil. Los resultados presentados se obtuvieron del primer campo de este proyecto de investigación y se llevaron a cabo mediante la metodología de transecto móvil, contemplando las rutas sur-norte y oeste-este para la recolección de datos de temperatura del aire, con el fin de para comprender los contrastes térmicos de la ciudad de Juazeiro do Norte. El transecto se realizó durante la estación lluviosa y comenzó a las 21:00 horas, sin exceder los 50 minutos, recogiendo una temperatura total de 25 puntos distribuidos en el perímetro urbano y considerando las características geoambientales y geourban. Las grabaciones se realizaron utilizando un termómetro digital con sensor externo con cable Icotem de 2 m y un receptor del Sistema de Posicionamiento Global (GPS) Garmin Map 76CSX para marcar las coordenadas UTM de los respectivos registros de temperatura. Las temperaturas más altas, de 24.8ºC a 25.8ºC, se registraron en espacios densamente construidos, la más baja, entre 22.6ºC a 23ºC, se observó en áreas con características rurales y menos urbanizadas.Palabras clave: isla de calor. Clima urbano. Transecto móvil.


2013 ◽  
Vol 6 (1) ◽  
pp. 767-793
Author(s):  
A. Barreto ◽  
E. Cuevas ◽  
B. Damiri ◽  
P. M. Romero ◽  
F. Almansa

Abstract. In this paper we present the preliminary results of atmospheric column integrated water vapor (PWV) obtained with a new Lunar Cimel photometer (LC) at the high mountain Izaña Observatory in the period July–August, 2011. We have compared nocturnal PWV from LC with PWV from a Global Positioning System (GPS) receiver and nighttime radiosondes (RS92). LC data have been calibrated using the Lunar Langley Method (LLM). We complemented this comparative study using quasi-simultaneous daytime PWV from Cimel AERONET (CA), GPS and RS92. Comparison of daytime PWV from CA shows differences against GPS and RS92 up to 0.18 cm. Two different filters, with and approximate bandwidth of 10 nm and central wavelengths at 938 nm (Filter#1) and 937 nm (Filter#2), were mounted into the LC. Filter#1 is currently used in operational AERONET sunphotometers. PWV obtained with LC-Filter#1 showed an overestimation above 0.18 and 0.25 cm compared to GPS and RS92, respectively, meanwhile Filter#2, with a reduced out-of-band radiation, showed very low differences compared with the same references (≤0.03 cm). These results demonstrate the ability of the new lunar photometer to obtain accurate and continuous PWV measurements at night in addition to the notably influence of the filter's transmissivity response on PWV determination at nighttime. The use of enhanced bandpass filters in lunar photometry, which is affected by more important inaccuracies than sun-photometry, is necessary to infer PWV with similar precision than AERONET.


Author(s):  
G.A. Akinyemi ◽  
L.B. Kolawole ◽  
O.F. Dairo ◽  
Alexander A. Willoughby ◽  
R.B. Abdulrahim ◽  
...  

An investigation on the diurnal and seasonal variability of ionospheric Total Electron Content (TEC) over Nigeria is carried out in this study using Global Positioning System (GPS) observable. Nigeria coordinates fall within the trough of equatorial ionization anomaly region of African sector. The TEC data used were obtained from the ground-based GPS receiver stations of the Nigerian GNSS network of stations (NIGNET). The stations with their respective geomagnetic latitudes are Abuja (−1.64º), Yola (−1.32º), Zaria (−0.13º) and Kebbi (0.72º). The results of the diurnal analysis of the relative variability index (VD) revealed higher nighttime values than daytime values. The diurnal variation of VD also showed two conspicuous peaks: the post-midnight and the post-sunset. The diurnal-seasonal variation does not reveal any consistent pattern (no particular season leads the others throughout). On the average, considering all the seasons together maximum TEC variability occurred in Zaria (62%) and least in Yola (54%). Seasonally, maximum VD was recorded during March equinox and the least was recorded during December equinox.


2009 ◽  
Vol 20 (7) ◽  
pp. 075105 ◽  
Author(s):  
Ta-Kang Yeh ◽  
Cheinway Hwang ◽  
Guochang Xu ◽  
Chuan-Sheng Wang ◽  
Chien-Chih Lee

Author(s):  
P.J. Zabinski ◽  
B.K. Gilbert ◽  
P.J. Zucarelli ◽  
D.V. Weninger ◽  
T.W. Keller

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