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      <h1>Adjust adp Object to Account for Spherical Spreading</h1>
      <small class="dont-index">Source: <a href="https://github.com/dankelley/oce/blob/HEAD/R/adp.R" class="external-link"><code>R/adp.R</code></a></small>
      <div class="d-none name"><code>beamUnspreadAdp.Rd</code></div>
    </div>

    <div class="ref-description section level2">
    <p>Compensate ADP signal strength for spherical spreading.</p>
    </div>

    <div class="section level2">
    <h2 id="ref-usage">Usage<a class="anchor" aria-label="anchor" href="#ref-usage"></a></h2>
    <div class="sourceCode"><pre class="sourceCode r"><code><span><span class="fu">beamUnspreadAdp</span><span class="op">(</span></span>
<span>  <span class="va">x</span>,</span>
<span>  count2db <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="fl">0.45</span>, <span class="fl">0.45</span>, <span class="fl">0.45</span>, <span class="fl">0.45</span><span class="op">)</span>,</span>
<span>  asMatrix <span class="op">=</span> <span class="cn">FALSE</span>,</span>
<span>  debug <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/options.html" class="external-link">getOption</a></span><span class="op">(</span><span class="st">"oceDebug"</span><span class="op">)</span></span>
<span><span class="op">)</span></span></code></pre></div>
    </div>

    <div class="section level2">
    <h2 id="arguments">Arguments<a class="anchor" aria-label="anchor" href="#arguments"></a></h2>


<dl><dt id="arg-x">x<a class="anchor" aria-label="anchor" href="#arg-x"></a></dt>
<dd><p>an <a href="adp-class.html">adp</a> object.</p></dd>


<dt id="arg-count-db">count2db<a class="anchor" aria-label="anchor" href="#arg-count-db"></a></dt>
<dd><p>a set of coefficients, one per beam, to convert from beam
echo intensity to decibels.</p></dd>


<dt id="arg-asmatrix">asMatrix<a class="anchor" aria-label="anchor" href="#arg-asmatrix"></a></dt>
<dd><p>a boolean that indicates whether to return a numeric matrix,
as opposed to returning an updated object (in which the matrix is cast to a
raw value).</p></dd>


<dt id="arg-debug">debug<a class="anchor" aria-label="anchor" href="#arg-debug"></a></dt>
<dd><p>an integer specifying whether debugging information is
to be printed during the processing. This is a general parameter that
is used by many <code>oce</code> functions. Generally, setting <code>debug=0</code>
turns off the printing, while higher values suggest that more information
be printed. If one function calls another, it usually reduces the value of
<code>debug</code> first, so that a user can often obtain deeper debugging
by specifying higher <code>debug</code> values.</p></dd>

</dl></div>
    <div class="section level2">
    <h2 id="value">Value<a class="anchor" aria-label="anchor" href="#value"></a></h2>
    <p>An <a href="adp-class.html">adp</a> object.</p>
    </div>
    <div class="section level2">
    <h2 id="details">Details<a class="anchor" aria-label="anchor" href="#details"></a></h2>
    <p>First, beam echo intensity is converted from counts to decibels, by
multiplying by <code>count2db</code>.  Then, the signal decrease owing to
spherical spreading is compensated for by adding the term
\(20\log10(r)\), where \(r\) is the distance from the
sensor head to the water from which scattering is occurring.  \(r\) is
given by <code>x[["distance"]]</code>.</p>
    </div>
    <div class="section level2">
    <h2 id="references">References<a class="anchor" aria-label="anchor" href="#references"></a></h2>
    <p>The coefficient to convert to decibels is a personal
communication.  The logarithmic term is explained in textbooks on acoustics,
optics, etc.</p>
    </div>
    <div class="section level2">
    <h2 id="see-also">See also<a class="anchor" aria-label="anchor" href="#see-also"></a></h2>
    <div class="dont-index"><p>Other things related to adp data:
<code><a href="sub-sub-adp-method.html">[[,adp-method</a></code>,
<code>[[&lt;-,adp-method</code>,
<code><a href="ad2cpCodeToName.html">ad2cpCodeToName</a>()</code>,
<code><a href="ad2cpHeaderValue.html">ad2cpHeaderValue</a>()</code>,
<code><a href="adp.html">adp</a></code>,
<code><a href="adp-class.html">adp-class</a></code>,
<code><a href="adpAd2cpFileTrim.html">adpAd2cpFileTrim</a>()</code>,
<code><a href="adpConvertRawToNumeric.html">adpConvertRawToNumeric</a>()</code>,
<code><a href="adpEnsembleAverage.html">adpEnsembleAverage</a>()</code>,
<code><a href="adpFlagPastBoundary.html">adpFlagPastBoundary</a>()</code>,
<code><a href="adpRdiFileTrim.html">adpRdiFileTrim</a>()</code>,
<code><a href="adp_rdi.000.html">adp_rdi.000</a></code>,
<code><a href="applyMagneticDeclination-adp-method.html">applyMagneticDeclination,adp-method</a></code>,
<code><a href="as.adp.html">as.adp</a>()</code>,
<code><a href="beamName.html">beamName</a>()</code>,
<code><a href="beamToXyz.html">beamToXyz</a>()</code>,
<code><a href="beamToXyzAdp.html">beamToXyzAdp</a>()</code>,
<code><a href="beamToXyzAdpAD2CP.html">beamToXyzAdpAD2CP</a>()</code>,
<code><a href="beamToXyzAdv.html">beamToXyzAdv</a>()</code>,
<code><a href="binmapAdp.html">binmapAdp</a>()</code>,
<code><a href="enuToOther.html">enuToOther</a>()</code>,
<code><a href="enuToOtherAdp.html">enuToOtherAdp</a>()</code>,
<code><a href="handleFlags-adp-method.html">handleFlags,adp-method</a></code>,
<code><a href="is.ad2cp.html">is.ad2cp</a>()</code>,
<code><a href="plot-adp-method.html">plot,adp-method</a></code>,
<code><a href="read.adp.html">read.adp</a>()</code>,
<code><a href="read.adp.ad2cp.html">read.adp.ad2cp</a>()</code>,
<code><a href="read.adp.nortek.html">read.adp.nortek</a>()</code>,
<code><a href="read.adp.rdi.html">read.adp.rdi</a>()</code>,
<code><a href="read.adp.sontek.html">read.adp.sontek</a>()</code>,
<code><a href="read.adp.sontek.serial.html">read.adp.sontek.serial</a>()</code>,
<code><a href="read.aquadopp.html">read.aquadopp</a>()</code>,
<code><a href="read.aquadoppHR.html">read.aquadoppHR</a>()</code>,
<code><a href="read.aquadoppProfiler.html">read.aquadoppProfiler</a>()</code>,
<code><a href="rotateAboutZ.html">rotateAboutZ</a>()</code>,
<code><a href="setFlags-adp-method.html">setFlags,adp-method</a></code>,
<code><a href="subset-adp-method.html">subset,adp-method</a></code>,
<code><a href="subtractBottomVelocity.html">subtractBottomVelocity</a>()</code>,
<code><a href="summary-adp-method.html">summary,adp-method</a></code>,
<code><a href="toEnu.html">toEnu</a>()</code>,
<code><a href="toEnuAdp.html">toEnuAdp</a>()</code>,
<code><a href="velocityStatistics.html">velocityStatistics</a>()</code>,
<code><a href="xyzToEnu.html">xyzToEnu</a>()</code>,
<code><a href="xyzToEnuAdp.html">xyzToEnuAdp</a>()</code>,
<code><a href="xyzToEnuAdpAD2CP.html">xyzToEnuAdpAD2CP</a>()</code></p></div>
    </div>
    <div class="section level2">
    <h2 id="author">Author<a class="anchor" aria-label="anchor" href="#author"></a></h2>
    <p>Dan Kelley</p>
    </div>

    <div class="section level2">
    <h2 id="ref-examples">Examples<a class="anchor" aria-label="anchor" href="#ref-examples"></a></h2>
    <div class="sourceCode"><pre class="sourceCode r"><code><span class="r-in"><span><span class="kw"><a href="https://rdrr.io/r/base/library.html" class="external-link">library</a></span><span class="op">(</span><span class="va"><a href="https://dankelley.github.io/oce/">oce</a></span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/utils/data.html" class="external-link">data</a></span><span class="op">(</span><span class="va">adp</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/plot.default.html" class="external-link">plot</a></span><span class="op">(</span><span class="va">adp</span>, which <span class="op">=</span> <span class="fl">5</span><span class="op">)</span> <span class="co"># beam 1 echo intensity</span></span></span>
<span class="r-plt img"><img src="beamUnspreadAdp-1.png" alt="" width="700" height="700"></span>
<span class="r-in"><span><span class="va">adp.att</span> <span class="op">&lt;-</span> <span class="fu">beamUnspreadAdp</span><span class="op">(</span><span class="va">adp</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/plot.default.html" class="external-link">plot</a></span><span class="op">(</span><span class="va">adp.att</span>, which <span class="op">=</span> <span class="fl">5</span><span class="op">)</span> <span class="co"># beam 1 echo intensity</span></span></span>
<span class="r-plt img"><img src="beamUnspreadAdp-2.png" alt="" width="700" height="700"></span>
<span class="r-in"><span><span class="co"># Profiles</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/par.html" class="external-link">par</a></span><span class="op">(</span>mar <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="fl">4</span>, <span class="fl">4</span>, <span class="fl">1</span>, <span class="fl">1</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="va">a</span> <span class="op">&lt;-</span> <span class="va">adp</span><span class="op">[[</span><span class="st">"a"</span>, <span class="st">"numeric"</span><span class="op">]</span><span class="op">]</span> <span class="co"># second arg yields matrix return value</span></span></span>
<span class="r-in"><span><span class="va">distance</span> <span class="op">&lt;-</span> <span class="va">adp</span><span class="op">[[</span><span class="st">"distance"</span><span class="op">]</span><span class="op">]</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/plot.default.html" class="external-link">plot</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/apply.html" class="external-link">apply</a></span><span class="op">(</span><span class="va">a</span>, <span class="fl">2</span>, <span class="va">mean</span><span class="op">)</span>, <span class="va">distance</span>, type <span class="op">=</span> <span class="st">"l"</span>, xlim <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="fl">0</span>, <span class="fl">256</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/lines.html" class="external-link">lines</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/apply.html" class="external-link">apply</a></span><span class="op">(</span><span class="va">a</span>, <span class="fl">2</span>, <span class="va">median</span><span class="op">)</span>, <span class="va">distance</span>, type <span class="op">=</span> <span class="st">"l"</span>, col <span class="op">=</span> <span class="st">"red"</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/legend.html" class="external-link">legend</a></span><span class="op">(</span><span class="st">"topright"</span>, lwd <span class="op">=</span> <span class="fl">1</span>, col <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"black"</span>, <span class="st">"red"</span><span class="op">)</span>, legend <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"original"</span>, <span class="st">"attenuated"</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-plt img"><img src="beamUnspreadAdp-3.png" alt="" width="700" height="700"></span>
<span class="r-in"><span><span class="co"># Image</span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/plot.default.html" class="external-link">plot</a></span><span class="op">(</span><span class="va">adp.att</span>, which <span class="op">=</span> <span class="st">"amplitude"</span>, col <span class="op">=</span> <span class="fu"><a href="oceColorsViridis.html">oce.colorsViridis</a></span><span class="op">(</span><span class="fl">100</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-plt img"><img src="beamUnspreadAdp-4.png" alt="" width="700" height="700"></span>
<span class="r-in"><span></span></span>
</code></pre></div>
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