diff --git a/topics/02_passive/index.md b/topics/02_passive/index.md
index fe3d8114ffed29369532df2031b953116d598c50..c989b3a000ce29470a31d7ab97599392eb3aa600 100644
--- a/topics/02_passive/index.md
+++ b/topics/02_passive/index.md
@@ -23,15 +23,13 @@ Photogrammetry was first documented by the Prussian architect [Albrecht Meydenba
 <img src="images/data_model_photogrammetry.png" alt="Data Model of Photogrammetry">
 
 
-## Accessibility
-Photogrammetry offers remarkable accessibility and affordability. Unlike other scanning methods that require precise orbital plans or specialized equipment, photogrammetry can be achieved simply by flying a drone in a circular pattern and capturing multiple photos. Utilizing the location data from the drone, one can construct detailed models like the example shown here. This accessibility makes photogrammetry an attractive option for various applications, with results that can be sufficiently accurate depending on the specific requirements.
+### Accessibility
+Unlike other scanning methods that require precise orbital plans or specialized equipment, photogrammetry can be achieved simply by flying a drone in a circular pattern and capturing multiple photos. Utilizing the location data from the drone, one can construct detailed models like the example shown here: A typical medium resolution aerial photogrammetry scan of a barn.
+With 50-100 images a reasonably accurate model can be produced. Such models are often used in surveying and restoration projects from the scale of hand helf objects to cities. This accessibility makes photogrammetry an attractive option for various applications, with results that can be sufficiently accurate depending on the specific requirements.
 
 <img src="images/house_scanning.jpg" alt="House">
-A typical medium resolution aerial photogrammetry scan of a barn.
-With 50-100 images a reasonably accurate model can be produced. Such models are often used in surveying and restoration projects from the scale of hand helf objects to cities.
 
-
-## Markers
+### Markers
 However, it's essential to note that photogrammetry lacks inherent scale. Without a reference point or prior knowledge of the camera locations, the resulting model lacks a definitive scale, as cameras inherently lack absolute scale information. Therefore, incorporating at least one reference point is crucial. For example, marking a facade with visual markers or known distances, such as pieces of tape, allows for scaling within a 3D modeling program based on these references.
 
 # Stereo Matching
@@ -41,10 +39,11 @@ However, it's essential to note that photogrammetry lacks inherent scale. Withou
 <p>Early uses in stereophotogrammetry, the estimation of 3d coordinates from measurements taken from two or more images through the identification of common points. This technology was used throughout the early 20th century for generating topographic maps.</p>
 
 <p><img src="images/stereo_plotter.jpg" alt="StereoPlotter"></p>
-<p>stereophotogrammetry is now being used for capturing dynamic characteristics of previously difficult to measure systems like running <a href="https://www.spiedigitallibrary.org/conference-proceedings-of-spie/8348/1/Dynamic-characteristics-of-a-wind-turbine-blade-using-3D-digital/10.1117/12.915377.short?SSO=1">wind turbines</a>.</p>
 
-<p>Photogrammetry is useful for outdoors settings, where all you need is a handheld camera and some patience. In this example, note the loss of quality towards the top, as pixel resolution becomes problematic:</p>
+While the analog versions of these techniques have waned in popularity, stereophotogrammetry still has applications for capturing dynamic characteristics of previously difficult to measure systems like running <a href="https://www.spiedigitallibrary.org/conference-proceedings-of-spie/8348/1/Dynamic-characteristics-of-a-wind-turbine-blade-using-3D-digital/10.1117/12.915377.short?SSO=1">wind turbines</a>.</p>
 
+### When is it useful?
+Photogrammetry is useful for outdoors settings, where all you need is a handheld camera and some patience. In this example, note the loss of quality towards the top, as pixel resolution becomes problematic:
 
 <div class="sketchfab-embed-wrapper"> <iframe title="Arc de Triomphe - photogrammetry" frameborder="0" allowfullscreen="" mozallowfullscreen="true" webkitallowfullscreen="true" allow="fullscreen; autoplay; vr" xr-spatial-tracking="" execution-while-out-of-viewport="" execution-while-not-rendered="" web-share="" src="https://sketchfab.com/models/65937fd27de647c0a8ac99ce8275c03e/embed"> </iframe> <p style="font-size: 13px; font-weight: normal; margin: 5px; color: #4A4A4A;"> <a href="https://sketchfab.com/3d-models/arc-de-triomphe-photogrammetry-65937fd27de647c0a8ac99ce8275c03e?utm_medium=embed&amp;utm_campaign=share-popup&amp;utm_content=65937fd27de647c0a8ac99ce8275c03e" target="_blank" style="font-weight: bold; color: #1CAAD9;"> Arc de Triomphe - photogrammetry </a> by <a href="https://sketchfab.com/nicolasdiolez?utm_medium=embed&amp;utm_campaign=share-popup&amp;utm_content=65937fd27de647c0a8ac99ce8275c03e" target="_blank" style="font-weight: bold; color: #1CAAD9;"> Nicolas Diolez </a> on <a href="https://sketchfab.com?utm_medium=embed&amp;utm_campaign=share-popup&amp;utm_content=65937fd27de647c0a8ac99ce8275c03e" target="_blank" style="font-weight: bold; color: #1CAAD9;">Sketchfab</a></p></div>