commit d2c5055dc6c65fa290f302461a5e37f9c8fcc081
parent abc3f9e167b4e31a00989802bacc7f01859096d3
Author: Najda Villefranque <najda.villefranque@lmd.ipsl.fr>
Date: Thu, 16 Feb 2023 16:45:29 +0100
htrdr: proofreading the overview page
Diffstat:
2 files changed, 64 insertions(+), 50 deletions(-)
diff --git a/htrdr/htrdr.html.in b/htrdr/htrdr.html.in
@@ -18,13 +18,12 @@
<p><code>htrdr</code> evaluates the intensity at any position (probe) of the
scene, in any direction, in the presence of <b>surfaces</b> and an <b>absorbing
-and diffusing semi-transparent medium</b>, for both <b>longwave</b> radiation
-sources (internal to the medium) and <b>shortwave</b> radiation sources
-(external to the medium). The intensity is calculated using the
-<b>Monte-Carlo</b> method: a number of optical paths are simulated backward,
-from the probe position and into the medium. Various algorithms are used,
-depending on the specificities of the nature and shape of the radiation
-source.</p>
+and diffusing semi-transparent medium</b>, for both <b>internal</b> (longwave)
+or <b>external</b> (shortwave) <b>radiation sources</b>. The intensity is
+calculated using the <b>Monte-Carlo</b> method: a number of optical paths are
+simulated backward, from the probe position and into the medium. Various
+algorithms are used, depending on the specificities of the nature and shape of
+the radiation source.</p>
<div class="news">
<p><b>Related articles</b></p>
@@ -55,11 +54,14 @@ interest, in their most common formats, in each scientific community.
<ol>
<li>
- <p><a href="man/man1/htrdr-atmosphere.1.html">Plane-parallel atmospheric
- radiative transfer</a>: a clear-sky atmosphere is vertically stratified,
- cloud thermodynamic data is provided on a 3D rectangular grid, and surface
- optical properties can be provided for an arbitrary number of materials.
- Internal radiation and solar radiation are taken into account.</p>
+ <p><a href="man/man1/htrdr-atmosphere.1.html">Atmospheric radiative
+ transfer</a>: a clear-sky atmosphere is vertically stratified, neglecting
+ Earth sphericity, and described in terms of absorption coefficients as a
+ function of height and spectral quadrature point as per a correlated-k model.
+ Cloud physical properties are provided on a 3D rectangular grid. Surface
+ geometrical and optical properties can be provided for an arbitrary number of
+ geometries. Internal radiation and solar radiation are taken into
+ account.</p>
</li>
<li>
<p><a href="man/man1/htrdr-combustion.1.html">Combustion processes</a>:
@@ -89,20 +91,20 @@ interest, in their most common formats, in each scientific community.
triangular mesh, with the possibility of using an arbitrary number of
materials. The radiative properties of a gas mixture must be provided on a
tetrahedral mesh, using the k-distribution spectral model. The radiative
- properties of an arbitrary number of aerosol modes can also be provided on
- their individual tetrahedral mesh. Calculations can be made for both internal
- and external radiation sources. In the case of an external source, a sphere
- of arbitrary size and position is used. This sphere can radiate as a Planck
- source at a specified brightness temperature, or using a high-resolution
- radiance spectrum.</p>
+ properties of an arbitrary number of aerosol and hydrometeores can also be
+ provided on their individual tetrahedral mesh. Calculations can be made for
+ both internal and external radiation sources. In the case of an external
+ source, a sphere of arbitrary size and position is used. This sphere can
+ radiate as a Planck source at a specified brightness temperature, or be
+ associated with a high-resolution radiance spectrum.</p>
</li>
</ol>
<p>Since any radiative transfer observable is expressed as an integral of the
-intensity, and since there is a strict equivalence between the integral to be
-solved and the underlying Monte-Carlo algorithm (each integral results in the
-sampling of a random variable), the algorithms that calculate the radiance are
-used for computing various quantities:</p>
+radiance, and since there is a strict equivalence between the integral to be
+solved and the underlying Monte-Carlo algorithm (each integral is associated
+with the sampling of a random variable), the algorithms that calculate the
+radiance are used for computing various quantities:</p>
<ul>
<li>
@@ -115,10 +117,9 @@ used for computing various quantities:</p>
</li>
<li>
<p><b>Flux density maps</b>, on a grid of sensors, integrated over an entire
- hemisphere. In the case of combustion chambers, only monochromatic flux maps
- can be calculated, while spectrally integrated flux density maps are also
- possible for atmospheric application, both for solar and thermal
- radiation.</p>
+ hemisphere. In the case of combustion chambers, flux density maps can be
+ calculated, while spectrally integrated flux density maps are also possible
+ for atmospheric application, both for solar and thermal radiation.</p>
</li>
</ul>
@@ -179,10 +180,11 @@ research projects:</p>
<li>In project <a
href="https://www.umr-cnrm.fr/spip.php?article1204">ModRadUrb</a> the
emphasis was put on taking into account the representation of <b>complex
- geometries</b> (detailled city scenes) using <b>spectral properties of a
+ geometries</b> (detailled city scenes) using <b>spectral properties of an
arbitrary number of materials</b>. The solver was extended to solve upward
- and downward <b>atmospheric fluxes</b> at any level in the scene, both in the
- visible and the infrared spectral ranges.</li>
+ and downward <b>hemispherical atmospheric fluxes</b> on a plane positioned
+ anywhere in the scene, both in the visible and the infrared spectral
+ ranges.</li>
<li>In project <a href="https://anr.fr/Projet-ANR-18-CE46-0012">MCG-Rad</a>
the <code>htrdr</code> codebase was used to explore a whole new class of
@@ -210,20 +212,33 @@ research projects:</p>
<b>arbitrary number of solid surfaces</b> (a planet, satellites) represented
by triangular meshes and materials which describe their <b>spectral
reflectivity/emissivity</b> properties. The <b>3D atmopshere</b> is defined
- by a number of participating semi-transparent media (a gas mixture and a
+ by a number of participating semi-transparent media (a gas mixture and an
arbitrary number of aerosol modes) whose radiative properties are provided at
- the nodes of a <b>unstructured tetraedric volumic grid</b>, independant for
- each medium.</li>
+ the nodes of a <b>unstructured tetrahedral volumetric grid</b>, independant
+ for each medium.</li>
</ul>
<h2>A straight interface</h2>
+<div class="img" style="width: 20em">
+ <a href="city.jpg"><img src="city.jpg" alt="city"></a>
+ <div class="caption">
+ Image rendered with <a
+ href="man/man1/htrdr-atmosphere.1.html">htrdr-atmosphere</a>, of a city
+ procedurally generated with spectral materials defined in particular from
+ data from the <a href="https://zenodo.org/record/4263842">Spectral Library
+ of impervious Urban Materials</a>. The entire dataset (geometry, materials
+ and cloud field) is included in the <a
+ href="htrdr-atmosphere-spk.html">atmosphere Starter-Pack</a>.
+ </div>
+</div>
+
<p><code>htrdr</code> is a <b>command-line tool</b> that performs computations
on input data, writes the rendered image and nothing more. No assumption is
-made on how input data are created excepted that they have to follow the
-expected file formats. In the same spirit, the output image is written in plain
-text, as a list of raw pixel estimations, making easier the processing of its
-data.
+made on how input data are created, the only requirement is compliance with
+the expected file formats. In the same spirit, the output image is written in
+plain text, as a list of raw pixel estimations, which makes it easier to
+post-process.
<p>This thin interface is, by nature, particularly well suited to be
<b>extended</b> and <b>integrated</b> into any workflow. For instance, one can
@@ -233,7 +248,7 @@ href="man/man1/htrdr-atmosphere.1.html">htrdr-atmosphere</a> directly in the
<a href=man/man5/htcp.5.html>htcp</a> file format or use the <a
href=man/man1/les2htcp.1.html>les2htcp</a> tool to convert cloud properties
from <a href="https://www.unidata.ucar.edu/software/netcdf/">NetCDF</a> to
-<code>htcp</code>. In the same way, the output image can be post-treated
+<code>htcp</code>. In the same way, the output image can be post-processed
through <a href="http://www.gnuplot.info">gnuplot</a> or converted in a regular
PPM image by the <a href="man/man1/htpp.1.html">htpp</a> program, and then
visualised in an image viewer as for instance <a
@@ -361,16 +376,16 @@ process and available options.</p>
W/m<sup>2</sup> computed by <a
href="man/man1/htrdr-atmosphere.1.html">htrdr-atmosphere</a> at 1 meter
height with the <a href=htrdr-atmosphere-spk.html>DZVAR</a> cloud field. The
- shortwave and longwave spectral integration ranges are [0.38, 4] µm
- and [4, 100] µm, respectively. Their spatially-avaraged flux is
- 879.349 W/m<sup>2</sup> in shortwave and 425.159 W/m<sup>2</sup> in
- longwave. In both cases, the spatial position is the sub-solar point, meaning
- that the sun is located at the zenith. In the shortwave map we observe the
- contrast between the shadows of the clouds and fully illuminated areas. In
- longwave, we can see the effect of clouds (higher values, due to the emission
- by the base of the cloud at higher temperatures than for a clear-sky zone)
- and also a "ripple" effect that is due to the spatial variations of water
- vapor concentration, as provided by the LES simulation.
+ SHORtwave and longwave spectral integration ranges are [0.38, 4] µm and
+ [4, 100] µm, respectively. Their spatially-avaraged flux is
+ 879.349 W/m<sup>2</sup> in shortwave and 425.159 W/m<sup>2</sup>
+ in longwave. In both cases, the sun is located at the zenith. In the
+ shortwave map we observe the contrast between the shadows of the clouds and
+ fully illuminated areas. In longwave, we can see the effect of clouds
+ (higher values, due to the emission by the base of the cloud at higher
+ temperatures than for a clear-sky zone) and also a "ripple" effect that is
+ due to the spatial variations of water vapor concentration, as provided by
+ the LES simulation.
</div>
</div>
diff --git a/htrdr/htrdr_build.sh b/htrdr/htrdr_build.sh
@@ -132,9 +132,8 @@ atmspk()
echo " <a href=\"DZVAR2.jpg\"><img src=\"DZVAR2.jpg\" alt=\"DZVAR2\"></a>"
echo " <a href=\"L12km_BOMEX.jpg\"><img src=\"L12km_BOMEX.jpg\" alt=\"L12_BOMEX\"></a>"
echo " <a href=\"L25_Fire.jpg\"><img src=\"L25_Fire.jpg\" alt=\"L25_Fire\"></a>"
- echo " <a href=\"city.jpg\"><img src=\"city.jpg\" alt=\"city\"></a>"
echo " <div class=\"caption\">"
- echo " Images of the DZVAR, DZVAR2, L12km_BOMEX, L25_Fire and city scenes"
+ echo " Images of the DZVAR, DZVAR2, L12km_BOMEX and L25_Fire scenes"
echo " rendered with <code>htrdr-atmosphere</code>."
echo " </div>"
echo "</div>"
@@ -144,7 +143,7 @@ atmspk()
echo "<div class=\"img\" style=\"margin-top:3em; width: 17em;\">"
echo " <a href=\"city_thin_lens.jpg\"><img src=\"city_thin_lens.jpg\" alt=\"city_thin_lens\"></a>"
echo " <div class=\"caption\">"
- echo " The image of the scene city_thin_lens rendered with"
+ echo " The image of the city scene rendered with"
echo " <code>htrdr-atmosphere</code>. The thin lens camera used in this"
echo " rendering focuses on background elements; the foreground vegetation"
echo " is out of focus."
