APPLICATIONS OF PHOTOGRAMMETRY TO SURVEYS OF GLACIERS IN CANADA AND ALASKA

1966 ◽  
Vol 3 (6) ◽  
pp. 783-798 ◽  
Author(s):  
Gottfried Konecny

The paper emphasizes that the choice of a proper procedure is essential for efficient glacier surveying. Terrestrial versus aerial photogrammetry and the use of electronic surveying procedures versus triangulation have been tested in surveys on the Athabasca and Saskatchewan glaciers, and on glaciers in northern Ellesmere Island, southeastern Alaska, and the Yukon Territory. The Otto Fiord glacier survey in northern Ellesmere Island demonstrates that no ground control is needed for volumetric glacier studies. Accurate maps needed for other studies depend on the establishment of control. Control can most efficiently be determined by tellurometer and phototheodolite with helicopter support, as shown in Alaskan glacier surveys. For large glaciers phototopography provides a good means of extending control from tellurometer traverse stations, as demonstrated in the Mount Kennedy survey. Simple one-color maps are an economical means of preserving survey results for future glaciological evaluation.

2014 ◽  
Vol 71 (5) ◽  
Author(s):  
Nurul Husna Aziz ◽  
Anuar Ahmad ◽  
Nurul Faratihah Ibrahim

Mapping can be intense and laborious with the current method in term of the work environment, manpower, cost, time, and obviously, the equipment used for the work. Traditional mapping technique uses photogrammetry, total station and GPS. The level for detailing and levelling is not convincing fast enough to catch up with the revolution of the world. However, aerial photogrammetry had been introduced to improve the mapping method in terms of accuracy, work done and speed. Unmanned Aerial System (UAS) is the latest realization of aerial photogrammetry to the mapping world. This technique is capable of mapping large area compared to conventional technique of mapping in short time with less work and effort, while the accuracy is maintained. This paper highlights the capability of UAS to replace the conventional technique of mapping. To test the accuracy of this product, the technique used in determining the ground control point (GCP) is studied. The accuracy of GPS plays big impact in the accuracy of the map produced, due to its role in establishing the GCP for the map. In this study, the conventional technique in determining the GCP is hereby replaced with better technique to produced better accuracy. The technique of GPS observation used is static with network processing which is never been used before in UAS. The concept here is the accuracy of map is improved by improving the accuracy of GCP. Furthermore the technique of GPS observation determined the accuracy of GCP. This paper, presents a new procedure using UAS for precise mapping and this method is expected to replace the conventional technique of producing topographic map.


2020 ◽  
Vol 12 (4) ◽  
pp. 501-509
Author(s):  
Nguyen Long ◽  
◽  
Le Thi Thu Ha ◽  
Tong Si Son ◽  
Kim Thi Thu Huong ◽  
...  

The use of lightweight Unmanned Aerial Vehicle with the aerial photogrammetry approach to construct the Digital Surface Model (DSM) has been effectively applied for various types of topography. However, the ability to carry out this approach for huge active open coal mines is insufficiently investigated, furthermore, the influences of topographical factors on the accuracy of DSM are ambiguous. This experiment attempts to apply the UAV method for the two active coal mines with the total area of 7.99 km2 , exploited at a range from -300 m to 300 m altitude to figure out the effect of topographic factors on the accuracy of DEM constructed from UAV images. A total of 972 UAV images and 17 ground control points have been coupled to construct DSM of the mines. Besides, 16 checking points located at different elevations are used to evaluate the accuracy of DEM and to define the influence. DEMs are generated with the maximum RMSE of 0.086 m, 0.099 m, and 0.170 m corresponding to X, Y, and Z dimensional errors. The results show the unclear correlation between the vertical accuracy of DEM and the relative elevation (R2=0.064), the general slope of the mines, and the number of ground control points using in the coal mines as well.


GEOMATICA ◽  
2014 ◽  
Vol 68 (4) ◽  
pp. 309-317 ◽  
Author(s):  
Chris Cryderman ◽  
S. Bill Mah ◽  
Aaron Shufletoski

This study quantifies the accuracies achieved and tests the validity of an in-house developed Unmanned Aerial Vehicle (UAV) system employed in a stockpile volumetric survey. UAV photogrammetric results are compared with conventional GNSS survey results. To test the repeatability of the UAV system, multiple flights were flown over the same stockpile using different GNSS ground control, at different times and weather conditions. Positional accuracies of UAV photogrammetric results were found to be very similar to those from GNSS RTK survey, at the scale of photography flown. UAV stockpile volume results agreed with those from GNSS within 3 755 m3 (0.7%) on a 530 255 m3 pile. Stockpile volume comparisons between subsequent UAV surface models agreed within 877 m3 (0.2%) on the same pile. Geometric analysis of independent UAV photogrammetric models over the same area indicated that they could be considered the same at a 95% confidence level. We conclude that the UAV photogrammetric approach is, at the very least, equivalent in accuracy to GNSS RTK surveys at the scale of photography observed. The accuracy of the UAV photogrammetric surveys were sufficient for 1:200 scale mapping and 0.145 m contours. The UAV photogrammetric approach also provided greater detail, resulting in more representative models of the measured surfaces.


1978 ◽  
Vol 48 ◽  
pp. 389-390 ◽  
Author(s):  
Chr. de Vegt

AbstractReduction techniques as applied to astrometric data material tend to split up traditionally into at least two different classes according to the observational technique used, namely transit circle observations and photographic observations. Although it is not realized fully in practice at present, the application of a blockadjustment technique for all kind of catalogue reductions is suggested. The term blockadjustment shall denote in this context the common adjustment of the principal unknowns which are the positions, proper motions and certain reduction parameters modelling the systematic properties of the observational process. Especially for old epoch catalogue data we frequently meet the situation that no independent detailed information on the telescope properties and other instrumental parameters, describing for example the measuring process, is available from special calibration observations or measurements; therefore the adjustment process should be highly self-calibrating, that means: all necessary information has to be extracted from the catalogue data themselves. Successful applications of this concept have been made already in the field of aerial photogrammetry.


2020 ◽  
Vol 29 (2) ◽  
pp. 290-299
Author(s):  
Julie G. Arenberg ◽  
Ray H. Hull ◽  
Lisa Hunter

Purpose From the Audiology Education Summit held in 2017, several working groups were formed to explore ideas about improving the quality and consistency in graduate education in audiology and externship training. The results are described here from one of the working groups formed to examine postgraduate specialization fellowships. Method Over the course of a year, the committee designed and implemented two surveys: one directed toward faculty and one toward students. The rationale for the survey and the results are presented. Comparisons between faculty and student responses are made for similar questions. Results Overall, the results demonstrate that the majority of both students and faculty believe that postgraduation specialization fellowships are needed for either 1 year or a flexible length. There was a consensus of opinion that the fellowship should be paid, as these would be designed for licensed audiologists. Most believed that the fellowships should be “governed by a professional organization (e.g., American Speech-Language-Hearing Association, American Academy of Audiology, American Doctors of Audiology, etc.),” or less so, a “separate body for this specific purpose.” Potential topics for specialization identified were the following: tinnitus, vestibular, cochlear implants, pediatrics, and intraoperative monitoring. The highest priority attributes for a specialization site were “abundant access to patient populations,” “staff of clinical experts,” and “active research.” The weight put toward these attributes differed between faculty and students with faculty prioritizing “university/academic centers,” and “access to academic coursework in the fellowship area.” The faculty rated “caseload diversity,” “minimum hours,” “research,” and “academic affiliation” as requirements for a fellowship site, with less weight for “coursework” and “other.” Finally, the students valued “improved personal ability to provide exceptional patient care,” “the potential for increased job opportunities,” and the “potential for a higher salary” as benefits most important to them, with lower ratings for “recognition as a subject matter expert” or “potential pathway to Ph.D. program.” Conclusions As a result of the survey, further exploration of a postgraduate specialization fellowship is warranted, especially to determine funding opportunities to offset cost for the sites and to ensure that fellows are paid adequately.


2010 ◽  
Vol 19 (4) ◽  
pp. 100-107 ◽  
Author(s):  
Lindsay Kessel ◽  
Linda Sue Sickman

Abstract This study describes survey results measuring the knowledge undergraduate elementary education major students have about augmentative and alternative communication. Those students with experience and course knowledge surrounding AAC were more knowledgeable. Implications for speech-language pathologists (SLPs) will be addressed, including how SLPs can provide classroom teachers with classroom support for general education teachers.


ASHA Leader ◽  
2011 ◽  
Vol 16 (12) ◽  
pp. 22-23
Author(s):  
Amy Hasselkus
Keyword(s):  

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