ported 1d polynomial approximation from Java code

PolynomialApproximation.php

+<?php
+//require_once ('test-matrix-invert.php'); // matrix inversion
+class PolynomialApproximation
+{
+//    function __construct() {
+//    }
+    public $debugLevel = 1;
+    public $debugFile = null;
+    
+    public function polynomialApproximation1d($data, $N){
+        //$my_array = array_fill(0, $size_of_the_array, $some_data);
+        if ($this->debugFile === null){
+            $this->debugLevel = 0;
+        }
+        $S=array_fill(0,2*$N +1,0);  // new double [2*N+1];
+        $SF=array_fill(0,$N+1,0); // new double [N+1];
+        for ($i=0; $i < sizeof($data); $i++){
+            $wxn=(sizeof($data[$i]) > 2)? $data[$i][2] : 1.0;
+            if ($wxn > 0.0){ // save time on 0.0 that can be used to mask out some samples
+                $f=$data[$i][1];
+                $x=$data[$i][0];
+                for ($j=0; $j <= $N; $j++){
+                    $S[$j]+=$wxn;
+                    $SF[$j]+=$wxn * $f;
+                    $wxn *= $x;
+                }
+                for ($j = $N+1; $j < 2*$N;$j++){
+                    $S[$j] += $wxn;
+                    $wxn *= $x;
+                }
+                $S[2*$N] += $wxn;
+                if ($this->debugLevel > 1){
+                    if (sizeof($data[$i]) > 2)
+                        fprintf($this->debugFile,
+                            "polynomialApproximation1d() |".$i."|: x=|".$data[$i][0]."| f(x)=|".$data[$i][1]."| (w=\t|".$data[$i][2]."|\t)");
+                        else
+                            fprintf($this->debugFile,
+                            "polynomialApproximation1d() |".$i,"|: x=|".$data[$i][0]."| f(x)=|".$data[$i][1]."|\t)");
+                }
+            }
+        }
+        $M = $this->zeroMatrix($N+1,$N+1);
+        $B = $this->zeroMatrix($N+1,1);
+        for ($i=0; $i <= $N; $i++) {
+            $B[$i][0] = $SF[$i];
+            for ($j = 0; $j <= $N; $j++) $M[$i][$j]= $S[$i + $j];
+        }
+        $N1 = $N;
+        // TODO: use try/catch with solve
+        if ($this->debugLevel > 1){
+            fprintf($this->debugFile,
+                "polynomialApproximation1d(data,".$N.") M:\n");
+            $this->print_matrix($this->debugFile, $M);
+            fprintf($this->debugFile,
+                "polynomialApproximation1d() B:\n");
+            $this->print_matrix($this->debugFile, $B);
+        }
+            // while (!(new LUDecomposition(M)).isNonsingular() && (N1>0)){
+        $df = ($this->debugLevel > 2) ? $this->debugFile : null;
+        while ($N1 >= 0) { // make N=0 legal ?
+            try {
+                $M_inv = $this->matrixInvert($M,$df);
+                $R = $this->mmul($M_inv, $B);
+                if ($this->debugLevel > 1){
+                    fprintf($this->debugFile,
+                        "polynomialApproximation1d() solution=\n");
+                    $this->print_matrix($this->debugFile, $R);
+                }
+                $result=array_fill(0,$N+1,0); // new double [N+1];
+                for ($i = 0; $i <= $N1; $i++){
+                    $result[$i] = $R[$i][0];
+                }
+                return $result;
+                
+            } catch (Exception $e) {
+                echo 'Caught exception: ',  $e->getMessage(), ", reducing polynomial order\n";
+                if ($N1 < 0 ) {
+                    return null;
+                }
+                $N1--;
+                $M1 = $this->zeroMatrix($N+1,$N+1);
+                $B1 = $this->zeroMatrix($N+1,1);
+                for ($i = 0; $i <= $N1; $i++) {
+                    $B1[$i][0] = $B[$i][0];
+                    for ($j = 0; $j <= $N1; $j++){
+                        $M1[$i][$j] = $M[$i][$j];
+                    }
+                }
+                $M = $M1;
+                $B = $B1;
+            }
+        }
+        return null;
+    }
+    
+    
+    public function mmul($A, $B){
+        $M = sizeof($A);
+        $N = sizeof($A[0]);
+        if ($N != sizeof($B)){
+            throw new Exception('DImensions mismatch.');
+        }
+        $K = sizeof($B[0]);
+        $R = $this->zeroMatrix($M,$K);
+        for ($i = 0; $i < $M; $i++){
+            for ($j = 0; $j < $K; $j++){
+                for ($k = 0; $k < $N; $k++){
+                    $R[$i][$j] += $A[$i][$k] * $B[$k][$j];
+                }
+            }
+        }
+        return $R;
+    }
+    
+    public function zeroMatrix($m,$n=1){
+        $M = array_fill(0, $m, null);
+        for ($i = 0; $i < $m; $i++){
+            $M[$i] = array_fill(0, $n, 0.0);
+        }
+        return $M;
+    }
+    
+    /**
+     * Inverts a given matrix(downloaded from https://gist.github.com/unix1/7510208 )
+     *
+     * @param array $A matrix to invert
+     * @param string $debugFile if not null - output file for debug info
+     *
+     * @return array inverted matrix
+     */
+    public function matrixInvert($A, $debugFile = null)
+    {
+        /// @todo check rows = columns
+        
+        $n = count($A);
+        
+        // get and append identity matrix
+        $I = $this->identity_matrix($n);
+        for ($i = 0; $i < $n; ++ $i) {
+            $A[$i] = array_merge($A[$i], $I[$i]);
+        }
+        
+        if ($debugFile !== null) {
+            fprintf($debugFile, "\nStarting matrix:\n");
+            //		echo "\nStarting matrix: ";
+            $this->print_matrix($debugFile, $A);
+        }
+        
+        // forward run
+        for ($j = 0; $j < $n-1; ++ $j) {
+            // for all remaining rows (diagonally)
+            for ($i = $j+1; $i < $n; ++ $i) {
+                // if the value is not already 0
+                if ($A[$i][$j] !== 0) {
+                    // adjust scale to pivot row
+                    // subtract pivot row from current
+                    $scalar = $A[$j][$j] / $A[$i][$j];
+                    for ($jj = $j; $jj < $n*2; ++ $jj) {
+                        $A[$i][$jj] *= $scalar;
+                        $A[$i][$jj] -= $A[$j][$jj];
+                    }
+                }
+            }
+            //		if ($debug) {
+            if ($debugFile !== null) {
+                fprintf($debugFile, "\nForward iteration $j:\n");
+                //			echo "\nForward iteration $j: ";
+                $this->print_matrix($debugFile, $A);
+            }
+        }
+        
+        // reverse run
+        for ($j = $n-1; $j > 0; -- $j) {
+            for ($i = $j-1; $i >= 0; -- $i) {
+                if ($A[$i][$j] !== 0) {
+                    $scalar = $A[$j][$j] / $A[$i][$j];
+                    for ($jj = $i; $jj < $n*2; ++ $jj) {
+                        $A[$i][$jj] *= $scalar;
+                        $A[$i][$jj] -= $A[$j][$jj];
+                    }
+                }
+            }
+            //		if ($debug) {
+            if ($debugFile !== null) {
+                fprintf($debugFile, "\nReverse iteration $j:\n");
+                //			echo "\nReverse iteration $j: ";
+                $this->print_matrix($debugFile, $A);
+            }
+        }
+        
+        // last run to make all diagonal 1s
+        /// @note this can be done in last iteration (i.e. reverse run) too!
+        for ($j = 0; $j < $n; ++ $j) {
+            if ($A[$j][$j] !== 1) {
+                if ($A[$j][$j] == 0.0) {
+                    //		        echo "Denominator is zero, throwing exception: \n";
+                    throw new Exception('Singular matrix.');
+                }
+                $scalar = 1 / $A[$j][$j];
+                for ($jj = $j; $jj < $n*2; ++ $jj) {
+                    $A[$j][$jj] *= $scalar;
+                }
+            }
+            //		if ($debug) {
+            if ($debugFile !== null) {
+                fprintf($debugFile, "\n1-out iteration $j:\n");
+                //			echo "\n1-out iteration $j: ";
+                $this->print_matrix($debugFile, $A);
+            }
+        }
+        
+        // take out the matrix inverse to return
+        $Inv = array();
+        for ($i = 0; $i < $n; ++ $i) {
+            $Inv[$i] = array_slice($A[$i], $n);
+        }
+        
+        return $Inv;
+    }
+    
+    /**
+     * Prints matrix
+     * @param resource $debugFile debug file or null
+     * @param array $A matrix
+     * @param integer $decimals number of decimals
+     */
+    function print_matrix($debugFile, $A, $decimals = 6)
+    {
+        if ($debugFile === null){
+            $debugFile = fopen('php://stdout', 'w');
+        }
+        foreach ($A as $row) {
+            fprintf($debugFile, "[");
+            foreach ($row as $i) {
+                fprintf($debugFile, "\t" . sprintf("%01.{$decimals}f", round($i, $decimals)));
+            }
+            fprintf($debugFile,  "\t]\n");
+        }
+    }
+    
+    /**
+     * Produces an identity matrix of given size
+     *
+     * @param integer $n size of identity matrix
+     *
+     * @return array identity matrix
+     */
+    function identity_matrix($n)
+    {
+        $I = array();
+        for ($i = 0; $i < $n; ++ $i) {
+            for ($j = 0; $j < $n; ++ $j) {
+                $I[$i][$j] = ($i == $j) ? 1 : 0;
+            }
+        }
+        return $I;
+    }
+    
+    
+        
+    
+    
+    
+}
+

test_01.php

 <?php
+require_once('PolynomialApproximation.php');
 $motosat_ip= "192.168.1.250";
 $motosat_url= "http://".$motosat_ip."/motor.xml";
 $modem_ip = "192.168.0.1";
 //$modem_ip = "http://localhost/motosat/attic";
 //$modem_strengt_url = $modem_ip."/sqf/sqfdisp/index.html";
+//$modem_strengt_url_good = "http://localhost/motosat/attic/sqf/sqfdisp/index.html";
+//$modem_strengt_url_bad = "http://localhost/motosat/attic/sqf/sqfdisp/index.html1";
+//$modem_strengt_url = "http://192.168.0.1/sqf/sqfdisp/index.html";
 $modem_strengt_url = "http://".$modem_ip."/sqf/sqfdisp/index.html";
 $AZ_CPD = 12.74445;
 $EL_CPD = 75.78567;
@@ -17,6 +21,14 @@ $SK_CMAX =   931;
 $MODEM_THRESHOLD = 17.0; // consider something if modem strength is above
 $OVERSHOOT = 1; // final steps absolute error
 $LATE_STOP_AZ = 30; // steps
+
+// Rescan azimuth after noticed a satellite during area scan
+$AZ_PLAY = 1.0;         // Hysteresis caused by mechanical play (degrees)
+$AZ_RESCAN = 8;         // (degrees) around expected center
+$AZ_RESCAN_STEP = 0.25; // (degrees)
+$USABLE_FRACT =   0.6;  // use ony samples not less than this fraction of maximal
+$USABLE_POW =     1.0;  // transform (maxstrengh - strengh) by applying pow - 1.2 ...1.3 may have marginal improvements
+$ARGMAX_OURSIDE = 0.2;  // Allow  argmax outside of the measured range by this fraction 
 /*
 http://192.168.1.250/motor.xml?Action=ElUp&Distance=0.5&Units=1 0.5 degree up
 
@@ -30,155 +42,21 @@ http://192.168.1.250/motor.xml?Action=SkUp&Distance=1&Units=0 1 step sk +
 http://192.168.1.250/motor.xml?Action=SkDn&Distance=1&Units=0 1 step sk -
 http://192.168.1.250/motor.xml?Action=Stop&Distance=100&Units=1 - stop 
 
-
-$xml_state = simplexml_load_file("http://192.168.1.250/motor.xml");
-
-LEDState -> 1344
-SignalQuality -> 15.00, 0.00, 99.00
-SignalStrength -> 31.18
-SysStatus -> System initialized
-SkMotor -> 1
-SatSys -> 1
-MotorState -> 0
-DishAngle -> 9.97, 0.00, 0.00
-DishCount -> 127, 0, 465
-
-php > var_dump ($xml_state);
-object(SimpleXMLElement)#1 (10) {
-  ["State"]=>           string(1) "1"
-  ["LEDState"]=>        string(4) "1344"
-  ["SignalQuality"]=>   string(18) "15.00, 0.00, 99.00"
-  ["SignalStrength"]=>  string(5) "31.18"
-  ["SysStatus"]=>       string(18) "System initialized"
-  ["SkMotor"]=>         string(1) "1"
-  ["SatSys"]=>          string(1) "1"
-  ["MotorState"]=>      string(1) "0"
-  ["DishAngle"]=>       string(16) "9.97, 0.00, 0.00"
-  ["DishCount"]=>       string(11) "127, 0, 465"
-}
-  ["DishAngle"]=> string(22) "196.48, 114.98, -12.95"
-  ["DishCount"]=> string(15) "2504, 8714, 357" round to the 
-
-
-*/
-// Read Motosat state:
-/*
-$xml_state = simplexml_load_file($motosat_url);
-$SignalQuality = (explode(",",$xml_state->SignalQuality)[0]+0.0);
-$State =          $xml_state->State+0; // 1 - Ready, 2 - Busy
-$DishAngle =     explode(",",$xml_state->DishAngle);
-foreach ($DishAngle as $key => $value){
-    $DishAngle[$key] = $value + 0.0;
-}
-$DishCount =     explode(",",$xml_state->DishCount);
-foreach ($DishCount as $key => $value){
-    $DishCount[$key] = $value + 0;
-}
-
-localhost/motosat/test_01.php?el=114.98&az=196.48&nodbg
-8714: 114.98
-<!--array(3) {
-  [0]=>
-  float(196.48)
-  [1]=>
-  float(114)
-  [2]=>
-  float(-12.95)
-}
-array(3) {
-  [0]=>
-  float(2504.029536)
-  [1]=>
-  float(8639.56638)
-  [2]=>
-  float(356.997036)
-}
-array(3) {
-  [0]=>
-  int(2504)
-  [1]=>
-  int(8640)
-  [2]=>
-  int(357)
-}
---><!--array(3) {
-  [0]=>
-  int(2504)
-  [1]=>
-  int(8640)
-  [2]=>
-  int(357)
-}
-array(3) {
-  [0]=>
-  int(2504)
-  [1]=>
-  int(8714)
-  [2]=>
-  int(357)
-}
-string(62) "http://192.168.1.250/motor.xml?Action=ElDn&Distance=74&Units=0"
---><?xml version="1.0"?>
-<motosat><cycles>1</cycles></motosat>
-
-8639: 113.99
-view-source:http://localhost/motosat/test_01.php?el=114.98
-<!--array(3) {
-  [0]=>
-  float(196.48)
-  [1]=>
-  float(114.98)
-  [2]=>
-  float(-12.95)
-}
-array(3) {
-  [0]=>
-  float(2504.029536)
-  [1]=>
-  float(8713.8363366)
-  [2]=>
-  float(356.997036)
-}
-array(3) {
-  [0]=>
-  int(2504)
-  [1]=>
-  int(8714)
-  [2]=>
-  int(357)
-}
---><!--array(3) {
-  [0]=>
-  int(2504)
-  [1]=>
-  int(8714)
-  [2]=>
-  int(357)
-}
-array(3) {
-  [0]=>
-  int(2504)
-  [1]=>
-  int(8639)
-  [2]=>
-  int(357)
-}
-string(62) "http://192.168.1.250/motor.xml?Action=ElUp&Distance=75&Units=0"
---><?xml version="1.0"?>
-<motosat><cycles>1</cycles></motosat>
-string(61) "http://192.168.1.250/motor.xml?Action=ElDn&Distance=1&Units=0"
---><?xml version="1.0"?>
-<motosat><cycles>1</cycles></motosat>
-
-
-
 */
 
 //php > var_dump($DishAngle);
 //array(3) {[0]=> float(9.97), [1]=> float(0), [2]=> float(0)}
-$dbg_file = fopen("/home/eyesis/git/motosat/attic/logs/modem.log","w");
+$dbg_file = fopen("/home/eyesis/git/motosat/attic/logs/test03.log","w");
 fprintf($dbg_file,"test log\n");
 
+if (false) {
+    $data = Array(5,6,7,9,9,10,11,11,12,12,11,11,10,10,10,36,40,45,47,51,51,51,49,48,43,38,30,30,30,10,10,10,10);
+    $rslt = findMax1d($data, $USABLE_FRACT, $USABLE_POW, $ARGMAX_OURSIDE);
+    print_r($rslt);
+    print("\n");
+    exit (0);
+}
+
 if (false) {
     print("<p>".date('l jS \of F Y h:i:s A')."</p>");
     $modem_strength= getModemStrength();
@@ -192,15 +70,9 @@ if (false) {
 }
 
 
-$xml_state = simplexml_load_file($motosat_url);
-$DishCount =     explode(",",$xml_state->DishCount);
-foreach ($DishCount as $key => $value){
-    $DishCount[$key] = $value + 0;
-}
-$DishAngle =     explode(",",$xml_state->DishAngle);
-foreach ($DishAngle as $key => $value){
-    $DishAngle[$key] = floatval($value);
-}
+$xml_state = simplexml_load_file($motosat_url); // use current as default gor HTTP GET
+//$DishCount = getDishCounts (xml_state);
+$DishAngle = getDishAngles ($xml_state);
 
 $dbg =    false; // true;
 $multi=   true; // false;
@@ -223,18 +95,22 @@ $scan_mode = ($wnd_az > 0) || ($wnd_el > 0);
 
 if ($scan_mode){
     $xml_state = scan_window($min_strength, $DishAngle, $wnd_az, $wnd_el, $scan_step);
+    $Success =       $xml_state->Success;
+    
+    if (intval ($Success)){
+        peakAzimuth($xml_state, $AZ_PLAY,$AZ_RESCAN, $AZ_RESCAN_STEP, $USABLE_FRACT, $USABLE_POW, $ARGMAX_OURSIDE);
+        $xml_state = simplexml_load_file($motosat_url);
+    }
+    
     $xml = new SimpleXMLElement("<?xml version='1.0'?><motosat/>");
     $State =          $xml_state->State+0; // 1 - Ready, 2 - Busy
     $busy = ($State & 2) != 0;
     $SignalQuality = myfval(explode(",",$xml_state->SignalQuality)[0]);
-    $DishCount =     $xml_state->DishCount;
-    $DishAngle =     $xml_state->DishAngle;
-    $Success =       $xml_state->Success;
     
     $xml->addChild ('Success',(string) $Success );
     $xml->addChild ('SignalQuality',(string) $SignalQuality );
-    $xml->addChild ('DishAngle',(string) $DishAngle );
-    $xml->addChild ('DishCount',(string) $DishCount );
+    $xml->addChild ('DishAngle',$xml_state->DishAngle );
+    $xml->addChild ('DishCount',$xml_state->DishCountt );
     $xml->addChild ('busy',(string) $busy );
     $xml->addChild ('State',(string) $State );
 
@@ -271,6 +147,141 @@ header('Access-Control-Allow-Origin: *');
 printf($rslt);
 exit (0);
 
+function peakAzimuth($xml_state, $az_play,$az_range, $az_step, $fract, $pow = 1.0, $argmax_outside=0.2){
+    global $motosat_url,$dbg_file;
+    if ($xml_state === null){
+        $xml_state = simplexml_load_file($motosat_url);
+    }
+    $DishAngle =  getDishAngles ($xml_state);
+    $az_start_center = $DishAngle[0];
+    //move to sart rescan azimuth minus mechanical play
+    $DishAngle[0] = $az_start_center - $az_play - $az_range/2;
+    moveElAzSk_degrees($DishAngle);
+    $scan_strengths = Array();
+    for ($az = $az_start_center - $az_range/2;
+         $az < ($az_start_center + $az_range/2 + $az_step);
+         $az += $az_step){
+             $DishAngle[0] = $az;
+             moveElAzSk_degrees($DishAngle); // to be on the safe side re-read xml
+             $modem_strength= getModemStrength();
+             $scan_strengths[] = $modem_strength;
+     }
+     if ($dbg_file !== null) {
+        fprintf($dbg_file, "==== Azimuth scan strengths: ====\n");
+        fprintf($dbg_file, print_r($scan_strengths, 1));
+     }
+     $rel_argmax = findMax1d($scan_strengths, $fract, $pow, $argmax_outside);
+    if ($rel_argmax !== null) {
+        $az_argmax = $az_start_center - $az_range / 2 + $az_step * $rel_argmax;
+        if ($dbg_file !== null) {
+            fprintf($dbg_file, "reltive argmax = %f\n", $rel_argmax);
+            fprintf($dbg_file, "azimuth argmax = %f (was %f)\n", $az_argmax, $az_start_center);
+        }
+        $DishAngle[0] = $az_argmax - $az_play;
+        moveElAzSk_degrees($DishAngle);
+        $DishAngle[0] = $az_argmax;
+        moveElAzSk_degrees($DishAngle);
+    } else {
+        // for now - move back
+        if ($dbg_file !== null) {
+            fprintf($dbg_file, "****** Failed to find maximum, going to known position.\n");
+        }
+        $DishAngle[0] = $az_start_center;
+        moveElAzSk_degrees($DishAngle);
+    }
+     
+     
+     
+     return;
+}
+
+function findMax1d($data, $fract, $pow, $frac_outside = 0.2){
+    global $dbg_file;
+    $min= $data[0];
+    $max = $data[0];
+    $argmax = 0;
+    foreach ($data as $k => $v){
+        if ($v > $max) {
+            $max = $v;
+            $argmax = $k;
+        } else if ($v < $min) $min = $v;
+    }
+    $threshold = $min + ($max-$min)*$fract;
+    $k_min = $argmax;
+    while (($k_min > 0) && ($data[$k_min - 1] >= $threshold)){
+        $k_min--;
+    }
+    $k_max = $argmax;
+    $last = sizeof($data) - 1;
+    while (($k_max < $last) && ($data[$k_max + 1] >= $threshold)){
+        $k_max++;
+    }
+    $datap =  array_fill(0, sizeof($data),0);
+    for ($k = $k_min; $k <= $k_max; $k++){
+        $datap[$k] = $max - pow($max - $data[$k], $pow);
+    }
+    
+    $poly_data = Array();
+    for ($k = $k_min; $k <= $k_max; $k++){
+       $poly_data[] = Array($k-$argmax, $datap[$k]);
+    }
+    
+    $pa = new PolynomialApproximation();
+    $rslt = $pa->polynomialApproximation1d($poly_data, 2);
+    
+    if ($dbg_file) {
+        fprintf($dbg_file, "argmax= %d , k_min= %d, k_max = %d, max = %f, threshold = %f, rslt:\n",
+            $argmax, $k_min, $k_max, $max, $threshold);
+        fprintf($dbg_file,print_r($rslt,1));
+    }
+    
+    if ($rslt[2] >= 0){
+        if ($dbg_file) {
+            fprintf($dbg_file, "Could not find maximum coeff = \n".printr($rslt,1)."\n");
+        }
+        return null; // no maximum
+    }
+    /*
+    // debugging
+    $rslt[] = $argmax;
+    $rslt[] = $argmax - $rslt[1] / (2 * $rslt[2]);
+    $pre = array_fill(0, sizeof($data),0);
+    $diff= array_fill(0, sizeof($data),0);
+    for ($k = $k_min; $k <= $k_max; $k++){
+        $x = $k-$argmax;
+        $pre[$k]=$rslt[0]+$rslt[1]*$x+$rslt[2]*$x*$x;
+        $diff[$k]=$pre[$k]-$datap[$k];
+    }
+
+    for ($k = $k_min; $k <= $k_max; $k++){
+        printf("[%02d]: %8.3f %8.3f %8.3f %8.3f\n", $k, $data[$k], $datap[$k], $pre[$k], $diff[$k]);
+    }
+
+    print("data\n");
+    print_r($data);
+    print("datap\n");
+    print_r($datap);
+    print("---datap\n");
+//    print_r($pre);
+//    print_r($diff);
+    */
+//    $frac_outside = 0.2;
+    $rel_argmax = $argmax - $rslt[1] / (2 * $rslt[2]);
+    if ($rel_argmax < -($frac_outside * sizeof($data))){
+        if ($dbg_file) {
+            fprintf($dbg_file, "argmax is too low = %f, range=%d\n",$rel_argmax,sizeof($data) );
+        }
+        
+        return null; // too low
+    }
+    if ($rel_argmax > ((1.0 + $frac_outside) * sizeof($data))){
+        if ($dbg_file) {
+            fprintf($dbg_file, "argmax is too high = %f, range=%d\n",$rel_argmax,sizeof($data) );
+        }
+        return null; // too low
+    }
+    return $rel_argmax; // $rslt;
+}
 
 /**
  * Scan rectangular AZ/EL window arownd expected satellite position, alternating 
@@ -333,20 +344,14 @@ function scan_window($threshold, $DishAngleCenter, $wnd_az, $wnd_el, $scan_step)
              if ($scan_rslt < 0) {
                  $xml_state = simplexml_load_file($motosat_url);
                  if ($dbg_file) {
-                     $DishAngle =     explode(",",$xml_state->DishAngle);
-                     foreach ($DishAngle as $key => $value){
-                         $DishAngle[$key] = floatval($value);
-                     }
+                     $DishAngle = getDishAngles ($xml_state);
                      fprintf($dbg_file, "\nDishAngle - after hitting/stopped:\n");
                      fprintf($dbg_file, print_r($DishAngle,1));
                  }
                  
                  //,$LATE_STOP_AZ
                  //move az back to compensate for late stop
-                 $DishCount =     explode(",",$xml_state->DishCount);
-                 foreach ($DishCount as $key => $value){
-                     $DishCount[$key] = $value + 0;
-                 }
+                 $DishCount =  getDishCounts($xml_state);
                  if ($dir > 0){
                      $DishCount[0] += $LATE_STOP_AZ;
                  } else {
@@ -355,17 +360,11 @@ function scan_window($threshold, $DishAngleCenter, $wnd_az, $wnd_el, $scan_step)
                  moveElAzSk_counts($DishCount);
                  if ($dbg_file) {
                      $xml_state = simplexml_load_file($motosat_url);
-                     $DishAngle =     explode(",",$xml_state->DishAngle);
-                     foreach ($DishAngle as $key => $value){
-                         $DishAngle[$key] = floatval($value);
-                     }
+                     $DishAngle = getDishAngles ($xml_state);
                      fprintf($dbg_file, "\nDishAngle - after backing:\n");
                      fprintf($dbg_file, print_r($DishAngle,1));
                  }
-                 
-                 
-                 $xml_state->addChild ('Success',(string) true );
-                 
+                 $xml_state->addChild ('Success',(string) 1 );
                  return $xml_state;
              }
         }
@@ -375,25 +374,26 @@ function scan_window($threshold, $DishAngleCenter, $wnd_az, $wnd_el, $scan_step)
     
     while (null !==moveElAzSk_degrees($DishAngleCenter));
     $xml_state = simplexml_load_file($motosat_url);
-    $xml_state->addChild ('Success',(string) false );
+    $xml_state->addChild ('Success',(string) 0 );
     return $xml_state;
 }
-
+//<b>49</b>
+//<b><font color=red>9</font></b>
 function getModemStrength(){ //0.2sec
     global $modem_strengt_url,$dbg_file;
-    $modem_page=file_get_contents("$modem_strengt_url");
+    $modem_page=file_get_contents($modem_strengt_url);
+//    $pstr="@<b>([^<]*)</b>@i";
+    $pstr="@<b>(<font[^>]*>)?([^<]*)</@i";
     $matches=null; // just define
-    preg_match('@<b>([^<]*)</b>@i',$modem_page, $matches);
-    return myfval($matches[1]);
+    preg_match($pstr,$modem_page, $matches);
+//    return myfval($matches[1]);
+    return myfval($matches[2]);
 }
 
 function moveElAzSk_start_counts($new_azelsk_count) {
     global $motosat_url, $AZ_CMAX, $EL_CMAX, $SK_CMAX,$OVERSHOOT,$dbg,$dbg_file;
     $xml_state = simplexml_load_file($motosat_url);
-    $DishCount =     explode(",",$xml_state->DishCount);
-    foreach ($DishCount as $key => $value){
-        $DishCount[$key] = intval($value);
-    }
+    $DishCount =  getDishCounts($xml_state);
     if ($DishCount[0] < 0) $DishCount[0] = 0;
     if ($DishCount[1] < 0) $DishCount[1] = 0;
     if ($DishCount[2] < 0) $DishCount[2] = 0;
@@ -531,10 +531,7 @@ function waitMotorsReady($modem_threshold = 0.0){ //
                     
                 }
                 // Now move back to where good signal strength was detected
-                $DishCountGood =     explode(",",$xml_state->DishCount);
-                foreach ($DishCountGood as $key => $value){
-                    $DishCountGood[$key] = $value + 0;
-                }
+                $DishCountGood =  getDishCounts($xml_state);
                 moveElAzSk_counts($DishCountGood);
                 
                 if ($dbg_file) {
@@ -582,6 +579,34 @@ function myfval ($s) {
     $s=trim($s,"\" ");
     return floatval($s);
 }
+/**
+ * Get 3 dish angles (az/el/sk) in degrees from the XML data received from controller
+ * @param $xml_state : XML data from the controller
+ * @return: array of 3 angles (degrees): azimuth, elevation, skew
+ */
+function getDishAngles($xml_state){
+    $DishAngles =     explode(",",$xml_state->DishAngle);
+    foreach ($DishAngles as $key => $value){
+        $DishAngles[$key] = floatval($value);
+    }
+    return $DishAngles;
+}
+
+/**
+ * Get 3 dish angles (az/el/sk) in counts from the XML data received from controller
+ * @param $xml_state : XML data from the controller
+ * @return: array of 3 angles (counts): azimuth, elevation, skew
+ */
+function getDishCounts($xml_state){
+    $DishCounts =     explode(",",$xml_state->DishCount);
+    foreach ($DishCounts as $key => $value){
+        $DishCounts[$key] = floatval($value);
+    }
+    return $DishCounts;
+}
+
+
+
 
 
 ?>
\ No newline at end of file