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Remote sensing
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87 changes: 75 additions & 12 deletions Satellites-sensors.html
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Expand Up @@ -90,8 +90,8 @@ <h1 class="text-light"><a href="index.html">Arun</a></h1>
<div class="d-flex justify-content-between align-items-center">
<h2>Portfolio Details</h2>
<ol>
<li><a href="portfolio-details-8.html" class="clickable-box">Go to Project page <i class="fas fa-arrow-right"></i></a></li>
<li><a href="index.html#portfolio" class="clickable-box">Go to portfolio</a></li>
<li><a href="Remote-sensing-content.html" class="clickable-box"><i class="fas fa-arrow-left"></i> Content </a></li>
<li><a href="index.html" class="clickable-box">Home <i class="fas fa-arrow-right"></i></a></li>
</ol>
</div>

Expand Down Expand Up @@ -127,7 +127,7 @@ <h2>Portfolio Details</h2>
<section id="portfolio-details" class="portfolio-details">
<div class="container">
<div class="row gy-4">
<h1>Data protection polices</h1>
<h1>Satellites and Sensors</h1>
<div class="image">
<figure style="text-align: center;">
<img src="assets/img/remote-sensing/remote-dataprocessing.png" alt="" style="max-width: 80%; max-height: 80%;">
Expand All @@ -136,7 +136,7 @@ <h1>Data protection polices</h1>
</div>

<section id="Section-1">
<h2>Analog photograph vs. Digital images in Remote Sensing: </h2>
<h2>Recording of energy by the sensor: </h2>
In remote sensing, it is very important to understand the data provided by sensors in order to interpret them properly. The first thing to do is to understand what a satellite image
is and why it is different from a photograph. The main difference between a photograph and a satellite image is that the photograph has an analogue format and is usually printed
on paper before being interpreted. The satellite image has a digital format and a computer is generally used to analyse and interpret it. The evolution of remote sensing techniques
Expand Down Expand Up @@ -228,15 +228,78 @@ <h4>The pixels</h4>

<img src="assets/img/remote-sensing/pixel-values.gif" alt="" style="max-width: 100%; max-height: 100%;">

<figure style="text-align: center;">
<img src="assets/img/remote-sensing/the-pixels-1.png" alt="" style="max-width: 100%; max-height: 100%;">
<figcaption style="text-align: center;"><strong>Image credit:</strong><a href="https://ieeexplore.ieee.org/document/6658949" target="_blank"> © Lefei Zhang et al.</a></figcaption>
</figure>



Human vision perceives color through detecting the entire visible spectrum, and our brains process this information into distinct colors. In contrast, many sensors work by capturing
information within narrow wavelength ranges, storing it in channels or bands. Digital representation involves combining and displaying these channels using primary colors
(blue, green, and red). Each channel's data is represented by one of these colors, and the relative brightness (digital value) of each pixel in each channel determines the
final color by combining the primary colors in varying proportions. <p></p>

<figure style="text-align: center;">
<img src="assets/img/remote-sensing/the-pixels-1.png" alt="" style="max-width: 100%; max-height: 100%;">
<figcaption style="text-align: center;"><strong>Image credit:</strong><a href="https://ieeexplore.ieee.org/document/6658949" target="_blank"> © Lefei Zhang et al.</a></figcaption>
</figure>
</section>

<section id="Section-2">
<h2>Satellite Characteristics: Orbits and Swaths </h2>
<h4>Orbits:</h4>
Satellites play a crucial role in various applications, including remote sensing, communication, and Earth observation. Two key characteristics defining satellite behavior are their orbits and swaths.
<figure style="text-align: center;">
<img src="assets/img/remote-sensing/orbit.png" alt="" style="max-width: 40%; max-height: 40%;">
<figcaption style="text-align: center;"><strong>Image credit:</strong><a href="https://arunp77.github.io/Arun-Kumar-Pandey/" target="_blank"> © Arun Kumar Pandey.</a></figcaption>
</figure>
<ol>
<li><strong>Low Earth Orbit (LEO):</strong>
<ul>
<li>Satellites in LEO orbit close to Earth, typically at altitudes ranging from about 180 to 2,000 kilometers.</li>
<li>LEO satellites offer advantages for remote sensing, providing high-resolution imagery and frequent revisits due to their shorter orbital periods.</li>
<li>Examples of LEO remote sensing satellites include the Landsat series and the International Space Station (ISS).</li>
</ul>
</li>

<li><strong>Medium Earth Orbit (MEO):</strong>
<ul>
<li>MEO satellites orbit at intermediate altitudes, typically between 2,000 and 35,786 kilometers.</li>
<li>These orbits provide a balance between coverage and resolution, making them suitable for a variety of applications, including navigation systems like GPS.</li>
<li>Examples of MEO satellites include those in the Global Navigation Satellite System (GNSS) constellations.</li>
</ul>
</li>

<li><strong>Geostationary Orbit (GEO):</strong>
<ul>
<li>GEO satellites are positioned at approximately 35,786 kilometers above the equator, allowing them to appear stationary relative to a fixed point on Earth.</li>
<li>These satellites provide continuous coverage of a specific region, making them ideal for applications like weather monitoring and communication.</li>
<li>Examples include weather satellites like GOES (Geostationary Operational Environmental Satellite).</li>
</ul>
</li>

<li><strong>Polar Orbit:</strong>
<ul>
<li>Satellites in polar orbits pass over Earth's poles, providing global coverage with each orbit.</li>
<li>These orbits are well-suited for Earth observation missions, as they cover the entire surface over time.</li>
<li>Examples include satellites from the Copernicus program, such as Sentinel-1 and Sentinel-2.</li>
</ul>
</li>
</ol>
<h4>Swaths:</h4>
The swath width refers to the coverage area on the Earth's surface captured by a satellite during a single pass. It is determined by the satellite's sensor characteristics and the
satellite's altitude. A wider swath allows for broader coverage but may sacrifice image resolution.

Understanding the interplay between orbits and swaths is essential for optimizing satellite mission design. LEO satellites, for instance, may have smaller swaths but offer higher revisit
frequencies, making them suitable for applications requiring frequent observations. GEO satellites, on the other hand, have a fixed view but cover a larger area with each pass, making
them ideal for continuous monitoring.
<figure style="text-align: center;">
<img src="assets/img/remote-sensing/swath.png" alt="" style="max-width: 100%; max-height: 100%;">
<figcaption style="text-align: center;"><strong>Image credit:</strong><a href="https://natural-resources.canada.ca/maps-tools-and-publications/satellite-imagery-and-air-photos/tutorial-fundamentals-remote-sensing/satellites-and-sensors/satellite-characteristics-orbits-and-swaths/9283" target="_blank"> © Remote Sensing Tutorials.</a></figcaption>
</figure>

<h3>Spatial Resolution, Pixel Size, and Scale</h3>

<h3>Spectral Resolution </h3>

</section>






Expand All @@ -246,7 +309,7 @@ <h4>The pixels</h4>



<section>
<section id="reference">
<h2>References</h2>
<ul>
<li><a href="https://www.esa.int/SPECIALS/Eduspace_EN/SEM4HR3Z2OF_0.html" target="_blank">Analogue versus digital images.</a></li>
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