Open and free education in geomatics, land surveying, and geodesy

The quality of immersion in virtual reality (VR) is largely defined by the display device. A regular monitor can simulate a virtual environment, but the experience remains non-immersive. Mobile phones, when paired with simple headsets like Google Cardboard or VR Box, can offer a semi-immersive experience, since they use motion sensors to adjust orientation and viewing angles.

For a fully immersive VR experience, advanced head-mounted displays (HMDs) are required. These devices integrate sensors, cameras, controllers, and sometimes even their own computing hardware to deliver seamless interaction and presence.

Semi-immersive VR devices

• Google Cardboard & VR Box: Affordable solutions that use smartphones as displays.
• Provide basic stereoscopic viewing by splitting the screen.
• Rely on elastic bands or handheld mounting, which is ergonomically limiting.
• Some devices support Bluetooth controllers for added interactivity.
• Pros: Cheap and accessible.
• Cons: Limited interaction and comfort; not truly immersive.

Fully immersive VR devices

VR headsets deliver immersive experiences with features:

Virtual and augmented reality (AR/VR) systems rely on a range of sensors to create immersive and interactive experiences. These sensors capture motion, direction, visuals, sound, and environmental factors to bridge between the real and virtual worlds.

Conventional AR/VR devices often use accelerometers, gyroscopes, magnetometers, and GPS for motion and location tracking. However, modern systems are adopting advanced technologies such as time-of-flight sensors, structured light, depth sensing, and thermal imaging to improve accuracy and realism.

Feedback sensors for touch, smell, and heat-based interactions are also being introduced, expanding the sensory dimension of VR/AR.

Together, these technologies help systems understand user movement, environment context, and interactions, delivering seamless immersion.

Below is a list of common sensors used in AR/VR systems and their typical usage.

Common sensors in AR/VR Systems

Source

• Siddiqui, M. S., Syed, T. A., Nadeem, A., Nawaz, W., & Alkhodre, A. (2022). Virtual tourism and digital heritage: an analysis of VR/AR technologies and applications. International Journal of Advanced Computer Science and Applications, 13(7).

GSD is one of the most important parameters when formalising the specifications for a photogrammetric project. Many decisions depend on the chosen GSD, such as:

• What altitude to fly for safety and coverage.
• What will be the data resolution of the flight.
• How to set up the camera for the expected resolution and accuracy.
• What level of detail can be achieved.
• How to plan flight paths to ensure sufficient image overlap and coverage.
• How to comply with project specifications or regulatory requirements for mapping accuracy.
• How to balance flight time, battery usage, and data quality.

Understanding of GSD helps optimize flight planning and data quality of the collected data.

Introduction

Ground Sampling Distance determines the amount of ground or surface area covered by a drone image.

Online virtual tour builders

Offline Virtual Tour Builders

• Stockpile Sample Report

• www.refseek.com - Academic Resource Search. More than a billion sources: encyclopedia, monographies, magazines.
• www.worldcat.org - a search for the contents of 20 thousand worldwide libraries. Find out where lies the nearest rare book you need.
• https://link.springer.com - access to more than 10 million scientific documents: books, articles, research protocols.
• www.bioline.org.br is a library of scientific bioscience journals published in developing countries.
• http://repec.org - volunteers from 102 countries have collected almost 4 million publications on economics and related science.
• www.science.gov is an American state search engine on 2200+ scientific sites. More than 200 million articles are indexed.
• www.pdfdrive.com is the largest website for free download of books in PDF format. Claiming over 225 million names.
• www.base-search.net is one of the most powerful researches on academic studies texts. More than 100 million scientific documents, 70% of them are free

Materials

Books

• MDPI books

Google Scholar

• photogrammetry
• LiDAR

Google Search

• Google Search Photogrammetry File type:pdf
• [Materials in the .pdf format from Agisoft]. Typein google search console: “agisoft.com fileytype:pdf”
• google search book photogrammetry
• “site:amazon.com “GNSS” book –”" search tools → Sort by: Publication Date"
• UAV+Lidar

Scientific bases

• Libary OAOPEN.org

RTCM3

RTCM (Radio Technical Commission For Maritime Services) standard 10403.3 or RTCM3 is the most widely used differential corrections standard among GNSS manufacturers and users today.

The introduction of MSM (Multiple Signal Message) within RTCM3 enabled significant advancements in multi-system and multi-signal GNSS data representation.

• RTCM3 corrections are BINARY.
  If a file with logged RTCM3 correction data is opened in a text editor like Notepad, it will appear as unreadable binary “garbage”.

Binary files, especially large ones, are better viewed using a file manager with HEX view (e.g., FAR).

Here are some tried-and-tested free (or low-cost) options how one can share orthophoto with users.

Export to Google Earth (KML/KMZ)

• QGIS or WebODM can export orthophoto into a .kml or .kmz.
• Clients open it directly in Google Earth.
• Pros: Easy to use, familiar interface.
• Cons: Requires basic setup and software install.

OpenAerialMap

• OpenAerialMap is a public platform to host and share aerial imagery.
• Best for open data or when one wants to make orthophotos available broadly.

DroneDB

• DroneDB offers an open-source way to organize, host, and share drone imagery.
• Includes a Hub for sharing orthomosaics.

Project Kiwi

• projectkiwi.io lets one upload and share orthophotos online.
• More polished than self-hosting, less technical than QGIS.

Zoomable

• Zoomable.ca supports large zoomable images, including geotiffs.
• Works like an online deep zoom viewer.

Simple viewers

• IrfanView: Lightweight viewer with plugins to handle geotiffs.

One year ago, after 12 years of working in academia and consultancy, I took the biggest career step of my life- starting my own company, in Switzerland, a country where I had lived for only 3.5 years.

This has been the most challenging job I have ever done. For me, nothing that I did until now compares to being a company owner: the main decision-maker and responsible person for everything.

During the year, the development of the company pushed me to the limits of my knowledge, skills, and dedication. It showed me how much I still have to learn about business, people and my profession. I wanted to quit several times, but through sheer willpower, managed to find self-motivation and discipline not to give up and continue.

From now on, I will use ‘we,’ since there are a couple of people helping run the company.

Looking back, we can be happy with the progress the company made. We established the technical operability, enabling us to offer a broad spectrum of geospatial services, including topographical surveying, construction surveying and reality capture.

Forums

• GEO-Forum – German-speaking forum on geodesy and surveying topics.
• GEOWebforum – Swiss forum for discussions about geoinformation.
• Laser Scanning Europe Forum – European community focused on 3D laser scanning.
• Laser Scanning Forum – A global hub for laser scanning professionals.
• Land Surveyors United – A social network for land surveyors worldwide.
• RPLS Forum – A long-standing forum for Registered Professional Land Surveyors.
• Surveying Hub – Focused on professional surveying discussions and knowledge sharing.
• Surveyor Connect – Forum for surveyors to discuss field practices, software, and GNSS tools.

Companies forum’s

• EMLID Forum – Community for Emlid GNSS products, RTK, and PPK workflows.
• Rockrobotic community forum
• Open Drone map

Linkedin

• The Business of Land Surveying

Reddit

• Reddit: Land Surveying – A global community for Land Surveyors to discuss all things surveying, from the office to the field.
• Reddit: LiDAR
• Reddit: UAVmapping
• Reddit: Laser Scanning – A community discussing 3D scanning technologies and workflows.

Facebook

• Facebook Drone Photogrammetry, +60k members
• Facebook Drone Mapping and Processing, +40k members
• Facebook List of photogrammetry groups
• Facebook Commercial Drone Mapping
• Facebook Geodesy and Engineering Surveying, +86k members

Introduction to SAR

Radar: measurement principle

Author: ANU Centre for Water and Landscape Dynamics, Expertise level: 🌟🌟☆☆☆, Our score: 🌟🌟🌟🌟☆

What professional camera and equipment solutions can reliably provide high-accuracy indoor geotagging?

Here are the options!

Indoor Geotagging and Mapping Technologies

Traditional GPS does not work indoors, so mapping systems combine cameras with alternate positioning. Solutions use combinations of LiDAR/SLAM, inertial/RTK fusion, wireless ranging (Wi‑Fi RTT, UWB), or optical tracking to tag images with position. For example, Wi‑Fi RTT (IEEE 802.11mc) on Android can achieve ~1–2 m accuracy indoors. Ultra-wideband (UWB) ranging can reach ~10–30 cm accuracy in line-of-sight setups, far better than Wi‑Fi or BLE. In practice, many high-end systems embed cameras in LiDAR/SLAM scanners or wearable units that self-localize with sub-decimeter precision. Common architectures include:

As 3D imaging technologies like LiDAR and laser scanning become more integral to industries ranging from architecture to autonomous vehicles, the need for standardized data formats has grown exponentially.

One such format is the E57 file format. It was created by the ASTM E57 Committee on 3D Imaging Systems to improve interoperability between different 3D scanning systems and software platforms.

What is the E57 format?

The E57 format (file extension .e57) is a vendor-neutral, open standard specifically developed for storing 3D imaging data. This includes:

If you have been processing GPS/GNSS data, you are probably familiar with some the online post processing services. These services are capable of producing centimeter-level positioning from static or kinematic observations. What you may not realize is there are many viable alternatives. All are free, (generally) easy to use, provide world-wide coverage, and (may) generate comparable results. Since each uses a unique baseline tool and processing strategies they form an excellent reality check against each other.

List of GPS/GNSS online post processing services

1. AUSPOS
2. Trimble CentrePoint RTX Post Processing
3. CSRS – Precise Point Positioning
4. Scripps Orbit and Permanent Array Center (SOPAC) – SCOUT
5. Automatic Precise Positioning Service (APPS) – JPL
6. Online Positioning User Service (OPUS)
7. magicGNSS/PPP
   • Some users have reported difficulties with uploading files or accessing the service.
8. Topaz Kernelsat
9. IBGE-PPP http://www.ppp-wizard.net/}{PPP Wizard}
10. GPS Solutions
11. Net Diff
12. Several services from Trimble Access

Resouces

• A Comparison of Free GPS Online Post-Processing Services

Link

Link

Link

Introduction

This post compares the outputs of seven different LiDAR and photogrammetry sensors when scanning the same tree. The goal is to highlight differences in data quality and density depending on the sensor.

Results

Analysis

Data density and detail vary widely**

• Terrestrial laser scanners (TLS) like the Faro Focus 3D X330 and Riegl VZ400i produce the highest point counts and densities, capturin g the most detailed representations of the tree.