Workshop on GPS GCP for UAV

A two-day workshop on GPS Ground Control Point for UAV Mapping were held at Seminar Room, FGRE on August 29 & 30. The event was organized by G&G Research Group led by Dr Tajul. About thirty participants attended the workshop.

Some of the G&G group members as listener

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Proceedings DMW Boston (1986)

The Proceedings of Deformation Measurements Workshop (held in Boston in winter 1986) is a very valuable reading. The engineering surveying group from UNB contributed a number of papers and all were included in the proceedings.

DMW Boston

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Deformation Measurement Workshop (1986)

I was given the opportunity to attend the Deformation Measurement Workshop (DMW) held in Boston in 1986. It was one of the early and major workshops on deformation measurement for geodetic application. The workshop was initiated by Mr Fritz Petersohn, President of Boston Survey Consultant, together with Prof Krakiwsky of Calgary University. The workshop is the second in the series after the successful of the first one (i.e.,  PEDS1 held at Calgary in 1985).

Photo with Prof Chen Yongqi at MIT Boston during DMW (1986)

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Sjoberg (1986) - Stokes modification and Hotine's formula

Sjoberg early papers was published in many publications which were not easy to access due to the unavailability of digital library at that time. One of Sjoberg's early paper was "The modification of Stokes and Hotine's formula: A comparison". It was presented at the International Symposium on Figure and Dynamics of the Earth, Moon and Planet held in Prague in 1986.

Sjoberg (1986)

[folder 15 Mei 2017]

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Physical Geodesy (Rummel 1992)

Lecture Notes from TU Delft. Covers contents prior to Champ era.

Lecture Notes (TU Delft)

Contents:

Phsical Geodesy I

1) Introduction; 2) gravitation; 3) series expansion of gravitational field; 4) moving measurement frame; 5) gravity; 6) gravimeter; 7) normal gravity field; 8) linear model of the Earth's gravity field; 9) potential differences and heights; 10) gravity reduction to sea level - a question of model precision; 11) solution of the Stokes problem; 12) geoid computation; 13) applications; Appendix Legendre functions and spherical harmonics.

Phsical Geodesy II

14) Representation of gravity anomalies; 15) Covariance modelling; 16) Introduction to collocation; 17) Spectral relationships of gravity quantities; 18) Pocket guides to Physical Geodesy

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Reference Reading on DS

Its about time to prepare and updating lecture materials on DS for the upcoming academic session. A set of new publications were gathered by glancing through online resources. Its about enough to help students to have some insight on the topic.

1. Detecting the unstable points in deformation monitoring geodetic networks in analysis method of subnetworks - Peyman Jevadi 2017 (source)
2. Structural deformation monitoring and analysis of highway bridge using accurate geodetic techniques - Beshr 2015. (source)
3. Structural data analysis for monitoring the deformation of oil storage tanks using geodetic techniques - Beshr 2014 J of SE. (source)
4. Ground-based Deformation Monitoring - Axel Ebeling 2014 PhD Diss (source)
5. Structural monitoring with geodetic survey of Quadrifoglio Condominium (Lecce) - Constantino & Angelini 2013. (source)
6. Deformation monitoring of flood prevention dams using geodetic and fibre optic measurement techniques - Lienhart et al 2013 - (source)
7. ETH Presentation - Networks & Deformation Analysis 2010 (source)
8. KTH Lecture (source)

International Workshop in Russia (2014)
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TU Munich - Rexter (2017)

Moritz Rexter has presented his PhD thesis entitled "Spectral soluutions to the topographic potential in the context of high-resolution global gravity field modelling". The thesis was submitted to TU Munich, March 2017. The examining committee consists of Dr-Ing C Hirt, Prof Roland Pail and Prof P Novak.

The title page (Rexter, 2017)

The contents

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Taklimat TNCAA

Satu majlis taklimat diadakan petang ini membincangkan perancangan penstrukturan fakulti di Utm.

Banner progam taklimat TNC

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Chalmers Uni - Geodetic VLBI & Space Geodesy

PhD Opportunity at Chalmers University, Sweden. Application is open for a candidate to pursue towards a phd in geodesy program at Chalmers. The area of study is Geodetic VLBI and Space Geodesy. the prospective candidate will work with the research group for Space Geodesy and Geodynamics which belongs to the Onsala Space Observatory Division at the Department of Space, Earth and Environment (DSEE).  [Chalmers U is slightly more than four hours drive from KTH].
Among the criteria specified candidates must have undertaken courses in space geodesy, orbit determination, adjustment theory, signal processing and statistics. Those courses are highly relevant and a merit for the position but not a strict requirement. The successful candidate shall have good knowledge in programming and should be able to deal with object-oriented code. Knowledge in Linux, C/C++, Python and shell scripting would be an asset. Basic knowledge in electronics, signal processing and statistical data analysis is desirable, too.

DSEE Chalmers is led by Professor Rudiger Haas (link)

Source - chalmers.

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WEF'98 "Do we need a gravimetric geoid ..."

It's now a long break period. Students are on their vacation until the new academic session in September. So its time to catch-up with some readings.

Found an old paper by WEF (1998) "Do we need a gravimetric geoid or a model of the AHD to transform GPS heights in Australia". Its in WF7 paper #9. The paper elaborated on why geoid and LVD is not coincide by giving a scenario example of Australia.

In answering the question mentioned in the title (WEF 1998) suggested that it is preferable to use a technique that accounts for the discrepancies between the vertical datum and gravimetric geoid model. This suggested approach yields a model of the separation between AHD and the WGS84 ellipsoid. WEF pointed out this serves as interim solution until readjustment of AHD/or re-definition of AHD.

Similar approach has been adopted for instance by Jiang & Duquenne (1996) - J of G; and in USA by Milbert 1995 - Geoid Bulletin 4.

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Operasi Mengemas Blok T06

Pagi ini dijalankan operasi untuk mengemas dan memindah barangan pejabat dan peralatan di Blok T06. Operasi tersebut dilaksana untuk menyusun kemas bilik Post-Graduate Office (yang telah di tempat semula balik ke C02). Bilik ini akan dijadikan bilik kuliah program IDP. Selain menyusun bilik PGO operasi yang diatur turut memindah peralatan ukur yang tersimpan di stor T06 untuk dipindah semula ke Blok B08.

Operasi memindah turun meja kaunter PGO

Memindah peralatan ukur antik dari T06
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Amos & WEF 2003 "Preparation of a new geoid model"

Source: Amos & WEF (2003) “Preparation of a new ....” NZ Surveyor

1. The paper described that free-air gravity anomalies were computed;

• from IGSN71-corrected gravity observations
• by subtracting the value of normal gravity at the geocentric observation latitude,
• then adding the second-order free air correction and atmospheric correction for the for the observation elevation (above local MSL)

2. A second-order free air correction is a more accurate representation of the vertical gradient of gravity for an ellipsoidal Earth because it takes into account the variation of normal gravity with latitude as well as higher order terms in height.

3. Why do atmospheric correction?

i) AC accounts for the mass-inconsistency between the GRS80 normal ellipsoid and gravity observed        on the Earth surface, as well as
ii) the gravitational attraction of the atmosphere above the gravity observation point,
iii)  AC also needed to make the terrestrial gravity anomalies consistent with those derived from the GGM

4. How to apply AC? Relevant formulas are given in

i) WEF (1995)
ii) WEF et al (1997)
iii)  Further work on AC is described by Sjoberg (2000)

Torge, 1989 – Gravimetry, Gruyter .... mentioned that the Potsdam gravity datum contains an error (... therefore IGSN71 global gravity datum should be used instead)

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