<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><!--StartFragment--><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Post Doc title: </span></p><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Assessing the sensibility of intervisibility on the quality of 3D geometry</span></p><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br data-mce-bogus="1"></span></p><p dir="ltr" style="line-height: 1.38; text-align: justify; margin: 0px;" data-mce-style="line-height: 1.38; text-align: justify; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Keywords:</span><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> Intervisibility, 3D reconstruction, computational geometry, digital twin</span></p><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br data-mce-bogus="1"></span></p><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Supervision:</span></p><ul style="margin-top: 0; margin-bottom: 0; padding-inline-start: 48px;" data-mce-style="margin-top: 0; margin-bottom: 0; padding-inline-start: 48px;"><li dir="ltr" style="list-style-type: disc; font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre;" aria-level="1" data-mce-style="list-style-type: disc; font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre;"><p dir="ltr" style="line-height: 1.38; text-align: justify; margin: 0px;" role="presentation" data-mce-style="line-height: 1.38; text-align: justify; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Supervisor: Bruno Vallet (LASTIG, IGN)</span></p></li><li dir="ltr" style="list-style-type: disc; font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre;" aria-level="1" data-mce-style="list-style-type: disc; font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre;"><p dir="ltr" style="line-height: 1.38; text-align: justify; margin: 0px;" role="presentation" data-mce-style="line-height: 1.38; text-align: justify; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Co-supervisor: Teng Wu (LASTIG, IGN)</span></p></li></ul><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br data-mce-bogus="1"></span></p><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Hosting Laboratory:</span></p><p dir="ltr" style="line-height: 1.38; margin: 0px;" data-mce-style="line-height: 1.38; margin: 0px;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">LASTIG Lab, IGN/ENSG, Champs sur Marne, France</span></p><b style="font-weight: normal;" id="docs-internal-guid-94844bb7-7fff-5546-b944-6d96fd586bd7" data-mce-style="font-weight: normal;"><br><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: bold; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Duration and start date: </span><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">1.5 years starting beginning of 2025</span></b></div><div><b style="font-weight: normal;" data-mce-style="font-weight: normal;"><span style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br data-mce-bogus="1"></span></b></div><div><span style="" data-mce-style="font-weight: normal;"><span style="background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; vertical-align: baseline;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><div style=""><strong><font face="Arial, sans-serif"><span style="font-size: 14.6667px; white-space-collapse: preserve;" data-mce-style="font-size: 14.6667px; white-space-collapse: preserve;">Topic:</span></font></strong></div><div style=""><span style="" data-mce-style="font-weight: normal;"><span style="background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; vertical-align: baseline;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><font face="Arial, sans-serif" style=""><span style="" data-mce-style="font-size: 14.6667px; white-space-collapse: preserve;"><div style=""><span style="font-size: 14.6667px; white-space-collapse: preserve;">Intervisibility is one of the application areas of 3D scene modeling, which consists of answering the question “Which points, which objects can be seen from which point?”. It is a useful technique in application fields such as security and defense, real estate, simulation of physical phenomena, antenna placement, etc.</span></div><div style=""><span style="font-size: 14.6667px; white-space-collapse: preserve;"><br></span></div><div style=""><span style="font-size: 14.6667px; white-space-collapse: preserve;">Modeling 3D scenes from various data sources is a subject widely studied by the scientific community. At IGN, the main data sources used are optical imagery and Lidar, acquired from terrestrial, aerial and space platforms. Depending on the data used and the reconstruction techniques, the quality of the modeling varies greatly. In the best case, the reconstruction method provides a more or less reliable indication of the geometric quality. In all cases, we can evaluate the quality externally by comparing the reconstruction to a ground truth known to be of much better quality. However, these evaluations are based on generic measurements not always adapted to the concrete use of 3D models.</span></div><div style="font-size: 14.6667px; font-weight: bold; white-space-collapse: preserve;"><br></div></span></font></span></span></div><div style=""><font face="Arial, sans-serif"><span style="font-size: 14.6667px; white-space-collapse: preserve;">The objective of this post-doc thesis is to develop a methodology to evaluate the sensitivity of intervisibility to the quality of the 3D geometric representation used to calculate it.</span></font></div><div style=""><font face="Arial, sans-serif"><span style="font-size: 14.6667px; white-space-collapse: preserve;">The geometric representations that we can use will be: </span></font><font face="Arial, sans-serif"><span style="font-size: 14.6667px; white-space-collapse: preserve;"></span></font></div><div style=""><font face="Arial, sans-serif"><span style="font-size: 14.6667px; white-space-collapse: preserve;">-Digital surface models, where the geometry is represented by a given height per pixel of a regular grid covering the area of interest</span></font></div><div style=""><font face="Arial, sans-serif"><span style="font-size: 14.6667px; white-space-collapse: preserve;">-3D surface meshes, where the geometry is represented by a set of contiguous triangles, and ideally waterproof.</span></font></div><div style=""><font face="Arial, sans-serif"><span style="font-size: 14.6667px; white-space-collapse: preserve;">-Structured models like LoD1 or 2 of the CityGML standard where each object in the scene has its own representation.</span></font></div><div style="color: rgb(0, 0, 0); font-family: Arial, sans-serif; font-size: 11pt; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; text-decoration-line: none; white-space: pre-wrap;"><br></div><div style="color: rgb(0, 0, 0); font-family: Arial, sans-serif; font-size: 11pt; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; text-decoration-line: none; white-space: pre-wrap;"><span style="" data-mce-style="font-weight: normal;"><span style="background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; vertical-align: baseline;" data-mce-style="font-size: 11pt; font-family: Arial,sans-serif; color: #000000; background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><strong>Full description</strong>:<b data-mce-style="font-weight: normal;" style="color: rgb(0, 0, 0); font-family: arial, helvetica, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; font-weight: normal;"> <a href="https://www.umr-lastig.fr/lastig_data/pdf/2024-PostDoc-Intervisibility.pdf" data-mce-href="https://www.umr-lastig.fr/lastig_data/pdf/2024-PostDoc-Intervisibility.pdf">https://www.umr-lastig.fr/lastig_data/pdf/2024-PostDoc-Intervisibility.pdf</a></b><!--EndFragment--> </span></span></div></span></span></div></div></body></html>