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@@ -41,18 +41,23 @@ However, it's essential to note that photogrammetry lacks inherent scale. Withou
 
 <p><img src="images/may_alexander_analog_photogrammetry.jpg" alt="Analog Photogrammetry"></p>
 
-*Intrinsics and extrinsics parameters*
-Intrinsic parameters describe the properties of a camera's lens and sensor
-Extrinsic parameters describe the camera's position and orientation in 3D space
 
-<p>Groundwork camera properties and standards for USGS photgrammetry surveys.</p>
-<a href="https://www.sciencedirect.com/science/article/abs/pii/0031866373900069">Welch 1973</a>
+Cameras were applied to photogrammetry as early as 1973, such as in
+[Imaging characteristics of photogrammetric camera systems](https://www.sciencedirect.com/science/article/abs/pii/0031866373900069)
+, an early paper describing groundwork camera properties and standards for USGS (United States Geological Survey) photgrammetry surveys.
+
+When describing photogrammetric camera systems, the following terminology are used to characterize systems: <br>
+*Intrinsics and extrinsics parameters*<br>
+Intrinsic parameters describe the properties of a camera's lens and sensor. <br>
+Extrinsic parameters describe the camera's position and orientation in 3D space
 
 
+Today:
 [Levenberg–Marquardt algorithm](https://en.wikipedia.org/wiki/Levenberg%E2%80%93Marquardt_algorithm) or damped least-squares algorithm (dls) are used to minimize the error across 3d coordinates. This procedure is typically called [bundle adjustment](https://en.wikipedia.org/wiki/Bundle_adjustment).
 
 
-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>
+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 [wind turbines](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).
+
 
 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: