Evaluation of a soft-copy photogrammetry system for tree-plot measurements

1993 ◽  
Vol 23 (9) ◽  
pp. 1781-1785 ◽  
Author(s):  
P.A. Gagnon ◽  
J.P. Agnard ◽  
C. Nolette
Keyword(s):  
Global Positioning System ◽  
Large Scale ◽  
Tree Height ◽  
Aerial Photographs ◽  
Positioning System ◽  
Crown Diameter ◽  
Forest Inventories ◽  
Global Positioning ◽  
Soft Copy

This article describes and evaluates the application of a soft-copy photogrammetry system to large-scale forest inventories. A specially designed software, developed by the authors, has been investigated in terms of accuracy and general operability. Tests based on 1:1100 color aerial photographs, taken with a 10-m cross-boom system and digitized at resolutions of 300, 450, and 600 dots per inch, confirmed the expected tree-height accuracies of 48, 32, and 24 cm, respectively. This indicates that a photographic scale of 1:800 and a scanning resolution of 800 dots per inch could produce a tree-height precision of the order of 10 cm. The tests have shown that model orientation takes about 15 min; for a tree plot of 24 trees, measurements (height and crown diameter) and observations (species and condition) also take about 15 min. As the important problem of positioning a helicopter over a tree plot has now been solved using global positioning system receivers, the results and information presented in this paper indicate that the existing technology can provide a rigorous and operational photogrammetric system for large-scale forest inventories and regeneration monitoring.

scholarly journals UAV ONBOARD GPS IN POSITIONING DETERMINATION

2016 ◽  
Vol XLI-B1 ◽  
pp. 1037-1042
Author(s):  
K. N. Tahar ◽  
S. S. Kamarudin
Keyword(s):  
Coordinate System ◽  
Global Positioning System ◽  
Large Scale ◽  
Control Point ◽  
Critical Issue ◽  
Ground Control ◽  
Positioning System ◽  
Ground Control Points ◽  
Global Positioning ◽  
Point Positioning

The establishment of ground control points is a critical issue in mapping field, especially for large scale mapping. The fast and rapid technique for ground control point’s establishment is very important for small budget projects. UAV onboard GPS has the ability to determine the point positioning. The objective of this research is to assess the accuracy of unmanned aerial vehicle onboard global positioning system in positioning determination. Therefore, this research used UAV onboard GPS as an alternative to determine the point positioning at the selected area. UAV is one of the powerful tools for data acquisition and it is used in many applications all over the world. This research concentrates on the error contributed from the UAV onboard GPS during observation. There are several points that have been used to study the pattern of positioning error. All errors were analyzed in world geodetic system 84- coordinate system, which is the basic coordinate system used by the global positioning system. Based on this research, the result of UAV onboard GPS positioning could be used in ground control point establishment with the specific error. In conclusion, accurate GCP establishment could be achieved using UAV onboard GPS by applying a specific correction based on this research.

An Off-Site Approach to Late Iron Age and Roman Landscapes on the Northern Plateau, Spain

2013 ◽  
Vol 16 (2) ◽  
pp. 289-313 ◽  
Author(s):  
Jesús García-Sánchez ◽  
Miguel Cisneros
Keyword(s):  
Iron Age ◽  
Global Positioning System ◽  
Large Scale ◽  
Survey Methodology ◽  
Field Survey ◽  
Positioning System ◽  
Late Iron Age ◽  
Castilla Y Leon ◽  
Global Positioning ◽  
New Settlements

Since 2009, a large-scale archaeological field survey – the Ager Segisamonensis Survey Project – has been carried out on the Northern Plateau of the Iberian Peninsula, in the Burgos province (Castilla y León), Spain. The aim of this project is to understand the Iron Age/Roman transition in terms of settlement strategies and landscape exploitation. The field survey has been undertaken in the landscape surrounding an Iron Age settlement and the successive Roman city of Segisamo – modern Sasamón. The goal is not the discovery of new settlements, but the recognition of the so-called ‘dwelling landscape’ and its evolution. In this article, we highlight our field survey methodology based on hand-held Global Positioning System (GPS) instruments and the creation of a recording system of ‘aggregation units'.

scholarly journals Shearwaters know the direction and distance home but fail to encode intervening obstacles after free-ranging foraging trips

2019 ◽  
Vol 116 (43) ◽  
pp. 21629-21633 ◽  
Author(s):  
Oliver Padget ◽  
Geoff Stanley ◽  
Jay K. Willis ◽  
Annette L. Fayet ◽  
Sarah Bond ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Large Scale ◽  
Positioning System ◽  
Global Positioning ◽  
Displacement Experiments ◽  
Integration Mechanisms ◽  
Gps Tracks ◽  
Free Ranging ◽  
Manx Shearwater ◽  
Pelagic Seabird

While displacement experiments have been powerful for determining the sensory basis of homing navigation in birds, they have left unresolved important cognitive aspects of navigation such as what birds know about their location relative to home and the anticipated route. Here, we analyze the free-ranging Global Positioning System (GPS) tracks of a large sample (n = 707) of Manx shearwater, Puffinus puffinus, foraging trips to investigate, from a cognitive perspective, what a wild, pelagic seabird knows as it begins to home naturally. By exploiting a kind of natural experimental contrast (journeys with or without intervening obstacles) we first show that, at the start of homing, sometimes hundreds of kilometers from the colony, shearwaters are well oriented in the homeward direction, but often fail to encode intervening barriers over which they will not fly (islands or peninsulas), constrained to flying farther as a result. Second, shearwaters time their homing journeys, leaving earlier in the day when they have farther to go, and this ability to judge distance home also apparently ignores intervening obstacles. Thus, at the start of homing, shearwaters appear to be making navigational decisions using both geographic direction and distance to the goal. Since we find no decrease in orientation accuracy with trip length, duration, or tortuosity, path integration mechanisms cannot account for these findings. Instead, our results imply that a navigational mechanism used to direct natural large-scale movements in wild pelagic seabirds has map-like properties and is probably based on large-scale gradients.

scholarly journals Prospects of GIS-Passportization of Natural Plague Foci in the Territory of the Russian Federation

2012 ◽  
pp. 48-53
Author(s):  
A. A. Kuznetsov ◽  
A. M. Porshakov ◽  
A. N. Matrosov ◽  
E. V. Kuklev ◽  
V. B. Korotkov ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Large Scale ◽  
Spatial Differentiation ◽  
Topographic Maps ◽  
Positioning System ◽  
Gis Technologies ◽  
Global Positioning ◽  
The Russian Federation ◽  
Methodological Approaches ◽  
High Degree

Characterized in brief are the results of natural plague foci passportization carried out in the late XX century. Evaluation of the principle of formalized spatial differentiation between enzootic territories is made. The principle can guarantee high degree of data ordering, obtained in the process of epizootiological surveillance. Therefore, prospects of a new stage of plague foci passportization based on GIS-technologies are viewed, the strategy is determined, and methodological approaches for its realization are put forward. Large-scale implementation of digital topographic maps and global positioning system into the work of plague control organizations is accentuated.

scholarly journals Estimating experienced racial segregation in US cities using large-scale GPS data

2021 ◽  
Vol 118 (46) ◽  
pp. e2026160118
Author(s):  
Susan Athey ◽  
Billy Ferguson ◽  
Matthew Gentzkow ◽  
Tobias Schmidt
Keyword(s):  
Global Positioning System ◽  
Large Scale ◽  
Racial Segregation ◽  
Gps Data ◽  
Income Mobility ◽  
Positioning System ◽  
Global Positioning ◽  
Highly Correlated ◽  
Transit Use ◽  
Us Cities

We estimate a measure of segregation, experienced isolation, that captures individuals’ exposure to diverse others in the places they visit over the course of their days. Using Global Positioning System (GPS) data collected from smartphones, we measure experienced isolation by race. We find that the isolation individuals experience is substantially lower than standard residential isolation measures would suggest but that experienced isolation and residential isolation are highly correlated across cities. Experienced isolation is lower relative to residential isolation in denser, wealthier, more educated cities with high levels of public transit use and is also negatively correlated with income mobility.

scholarly journals Self-Helpingly Exchanging and Charging Batteries for EN-V

2011 ◽  
Vol 2-3 ◽  
pp. 1093-1098
Author(s):  
Shu Ping Chen ◽  
Qing Chun Zhang ◽  
Xiang Fei Meng ◽  
Feng Hou Pan ◽  
Hong Lei Liu ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Large Scale ◽  
System Simulation ◽  
Simulation System ◽  
Intelligent Vehicle ◽  
Positioning System ◽  
Equipment Cost ◽  
Charging Time ◽  
Vehicle System ◽  
Global Positioning

An idea of self-helpingly exchanging and charging batteries is proposed to solve some Battery Exchanging and Charging (BEC, for short) problems of Electric-Networked Vehicles (short for, EN-V). Large scale BEC stations occupy large working area and need high equipment cost; common charge piles have disadvantages of long charging time. As a result, a physical demonstration system, which encompasses intelligent vehicle system, BEC stake system and GPS (Global Positioning System) simulation system, is established to validate the feasibility of the idea.

scholarly journals Glacier changes in southern Spitsbergen, Svalbard,1901–2000

2003 ◽  
Vol 37 ◽  
pp. 219-225 ◽  
Author(s):  
Anja Pälli ◽  
John C. Moore ◽  
Jacek Jania ◽  
Piotr Glowacki
Keyword(s):  
Global Positioning System ◽  
Ground Penetrating Radar ◽  
East Coast ◽  
Aerial Photographs ◽  
Positioning System ◽  
Digital Elevation ◽  
Glacier Changes ◽  
Global Positioning ◽  
Glaciated Valley ◽  
Ground Penetrating

AbstractHigh-resolution ground-penetrating radar surveys at 50 MHz on the polythermal glaciers Hornbreen, Hambergbreen and several surrounding glaciers in southern Spitsbergen, Svalbard, are presented and interpreted. Accurate positioning was obtained using differential global positioning system (DGPS). Digital elevation models (DEMs) of the bedrock and surface were constructed. Comparison of DGPS data and surface DEMs with data from the topographic mappings from 1936 oblique stereoscopic aerial photographs and from Mission Russe in 1899–1901 shows that the Hornbreen and Hambergbreen surfaces are about 60–100 m thinner today in the upper part than at the beginning of the 20th century. Hornbreen has retreated by 13.5 km from the central part of the front, and Hambergbreen by 16 km. All the fronts of the nearby east-coast glaciers in this area have retreated. The bedrock DEM shows that the Hornbreen and Hambergbreen beds lie at –25 to 25 m a.s.l. The combination of sub-sea-level fronts and increasing steepness of the glaciers suggests that the low-lying glaciated valley filled by Hornbreen and Hambergbreen may become a partially inundated ice-free isthmus within perhaps 100 years.

Sign in / Sign up

Export Citation Format

Share Document