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Survey 06 – How to Define a Geodesic Curve ?

Written By: Jean-Paul Cipria - Oct• 08•17
Geodesics - Osculating Plane - Normales

Geodesics – Osculating Plane – Normales

How to Define a Geodesic Curve ?

Raving Rabbids Earth

Done ! Raving Rabbids Earth

Complicated but Not Difficult - Bachelord Level

Complicated but Not Difficult – Bachelord Level

Created :2017-10-08 12:16:53. – Modified : 2017-10-14 13:01:29.

We are triing to navigate on earth or to « project » distances form a theorical ellipsoïd to a plane. Then how to be sure the distance between two points on ellipsoid is the minimum as possible BEFORE even think to project this distance on a certain map ?

Let’s go ? Do we try to understand some definitions in mathematics books or internet web sites ? Yes we do. And we loss of valuable time. Example ?

??? An osculating plane is a plane in a Euclidean space or affine space which meets a submanifold at a point in such a way as to have a second order of contact at the point. (Internaute site !) ???

Do we understand anything even where you have got a PhD in Physics ? No, we did’nt !

Then ?


Navigation 13 – Spherical Position and Local Plan – Spherical Trajectories ?

Written By: Jean-Paul Cipria - Août• 11•17
Spherical Trajectory - ©Jean-Paul Cipria 2017

Spherical Trajectory – ©Jean-Paul Cipria 2017

How do we set a Position on Earth and how we determine Local Coordinates and Perpendicular Plan ?

And then how do we find trajectories point by point on Earth ? With and … without Latitude and Longitude, only with an Absolute Rotation Angle ?

Done ... Un Café ?

Done … Un Café ?

Complicated but Not Difficult - Bachelord Level

Complicated but Not Difficult – Bachelord Level

Created :2017-08-11 16:09:53. – Modified : 2017-10-01 14:25:09.

We want to « navigate » on earth with direct trajectory from P point to B point but merely (simplement ?) use latitude and longitude ? When we are in local coordinates we use for a small instant an absolute directionnal vector. When all coordinates are aligned on a known axes meridian for exemple we can « trace » trajectory easily but … if we turn our spherical earth or our route as we can see on following pictures then problems begin.

Some web sites and bachelord courses describe local plan as we do on the first paragraph but how do we navigate without use d\varphi and d\theta like changes of tack on sailboat (virements de bord d’un voilier) ?

The same applies for telescopes, radars, robotic arms [CIPRIA-Robotics-2015], or satellites trajectories. We can’t do some thousands small iterations on elevation and azimut motors ! Did you see the NASA trajectories panels at TV when they launched spatial engines ? Here are the beginning of understanding how to … think and, as an arrow indicate direction and sens, how to do …


Jean-Paul Cipria

Written By: Jean-Paul Cipria - Oct• 02•17

Jean-Paul Cipria

Surveyor Topographer
Sciences for Engineers : 25 Years Experiences
cipria[ at ]


Created :2017-10-02 07:39:11. – Modified : 2017-10-20 20:44:27.

Quaternions de l'axe k - Rotations de vues 3d

How to Rotate a Satellite without Gimbal Locking ? Axis k Quaternions – 3D Views Rotations – ©J.P. Cipria

Khi2 - Erreur à 5% sur l'Exponentielle - ©J.P. Cipria

Khi² Measurements/Theory Matching – Example with à 5% Exponential Error – ©J.P. Cipria

2017 in Action

Surveyor and Topographer

  1. « Measurements on Earth. Why is it so Complex AND Difficult ? » – 09/2017.
    1. Leveling and Local Altimetry : How is the height of earth objects ?
    2. Covadis and Autocad Maps and Plans : How do we represent plane projections ?
    3. WGS84 and RFG89 : Global Geodetic Reference Frames.
      1. How do we locate earth on space ?
      2. How do we theorise an earth form for localisation in two dimensions ?
      3. How do we measure altitude in the third dimension and theorise another form on earth ?
      4. How are time and duration on earth ?
  2. Altitudes on Expert Measurements by reference to geoid.
  3. Angles, gisements and Positioning on Earth by reference to Conic Projection and by Ellipsoid.


Survey 05 – How to Project by Hand a Curve on a Plan by 45° Inclination ?

Written By: Jean-Paul Cipria - Oct• 01•17
Cylindric and Plane Intersections

Cylindric and Plane Intersections

Cylindric and Plane Intersections.
How to Project Curve with 45° Inclination Point of View ?

Done ... Un Café ?

Done … Un Café ?

Easy Level.

Created :2017-10-01 14:23:12. – Modified : 2017-10-01 17:37:12.


Survey 04 – What about a Job in Abu-Dhabi in 2017?

Written By: Jean-Paul Cipria - Sep• 30•17

Architecture – Model – Ref. [CIPRIA-Dubaï Creek Buliding-2017]

Have you got difficulties to find job in France ?

Land Surveyor, United Arab Emirates – Abu Dhabi

Job Summary

….. is seeking an experienced Land Surveyor major project located in Abu Dhabi. Plans, organizes, and directs work of one or more survey parties engaged in surveying earth’s surface to determine precise location and measurements of points, elevations, lines, areas, and contours for construction, map-making, land division, titles, mining or other purposes: Researches previous survey evidence, maps, deeds, physical evidence, and other records to obtain data needed for surveys.


Survey 03 – Sketch Plan

Written By: Jean-Paul Cipria - Sep• 27•17

How do we Draw a Sketch Plan ?

Sketch Plan - Croquis de Repérages - RN219 - Draveil

Sketch Plan – Croquis de Repérages – RN219 – Draveil

We use to implant Survey Nails when we Localize Object with a Millimeter Accuracy.