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Emitter Audio

1. Scan Period Scan Period 1 10 100 000 Period of one revolution around the axis of rotation Squint Angle deg Pattern Width 1 0 45 Angle between the axis of rotation and the emitter beam Figure 14 Conical Scan Given the Scan Period t the Squint Angle 8 the current time t and the initial time the model started emitting to the time within the cycle is determined by t t to mod 7 The rate of rotation of the conical movement around the axis of rotation is A 2nt o A T Then the position of the antenna at any given time is 0 6 COS a t SIN a t SimPhonics Incorporated Page 25 of 44 B Emitter Audio a 2 3 6 Spiral A spiral scan is similar to a conical scan except that the squint angle varies between a minimum of zero degrees and a maximum of Max Squint Angle degrees Figure 15 illustrates a spiral scan while Table 8 lists the additional input values that are required to model the scan As with the conical scan the axis of rotation of the spiral scan is defined to coincide with the Emitter Beam Reference Two scan periods are required to define the spiral scan The Spiral Scan Period is the time for the whole scan pattern while the Conical Scan Period is the time for a single revolution about the axis of rotation The Conical Scan Period must be less than the Spiral Scan Period Table 8 Spiral Scan Parameters EAG Object Range Range Description
2. Table 10 Helical Scan Parameters EAG Object Range Range Description Pin Name Min Max Helical Scan Period Scan Period 1 10 100 000 Period of complete helical pattern including retrace Vertical Extent deg Pattern Width 1 0 180 Maximum elevation angle relative to the starting elevation Circular Scan Period ms Scan Period 2 10 100 000 Period of single rotation Retrace Time ms Retrace Time 0 1000 Time after reaching the maximum elevation that the scan requires before starting to scan again at the starting elevation Starting Elevation deg Scan Elevation 90 90 The starting elevation of the scan pattern Figure 17 Helical Scan SimPhonics Incorporated Page 30 of 44 Emitter Audio Given the Circular Scan Period x the Helical Scan Period 12 the Starting Elevation po the current time t and the initial time the model started emitting to the time within the cycle is determined by tia t to mod Ti D t to mod T2 The time to complete the scanning portion of the cycle e not including the retrace is determined by tretrace 727 Retrace Time If the time within the cycle is within the retrace period the emitter is not transmitting if ti 2 gt tretrace then Received Power 0 Otherwise the circular rate of rotation is calculated as follows A 2 T o Aj t And the elevation rate is determined as follows A Vertical Exte
3. Note the L symbols denote an integer truncation of a real number Then the axis of rotation is given by Oaxis Ou Di Paxis dot The conical movement of the antenna is calculated as follows A 27 a Aalt 6 Squint Angle D t to mod T2 Then the position of the antenna at any given time is 0 Daxis 5 COS at 2 daxis 8 sin ati 2 SimPhonics Incorporated Page 36 of 44 B Emitter Audio a 2 3 12 Palmer Helical A Palmer Helical scan consists of an emitter beam that follows a conical scan superimposed on a Helical scan pattern The major motion of the scan is the Helical component of the scan which defines the motion of the axis of rotation of the conical component Figure 20 illustrates the typical pattern that results from a Palmer Helical scan Table 14 lists the additional input values that are required to model the Pa mer Helical scan This scan requires three scan periods to be specified The Helical Scan Period defines the time for the entire helical pattern including the retrace time while the Circular Scan Period defines the time for a single rotation i e in azimuth within the helical pattern The Conical Scan Period defines the time for a single revolution around the axis of rotation Table 14 Palmer Helical Scan Parameters EAG Object Range Range Description Pin Name Min Max Helical Scan Period ms Scan Period 1 10 100 000 Period of complete helical pattern incl
4. Main BW Back Power Back BW Table 16 EAG Object Left Side Pins Units Range Range Description pom o ES Enables and disables audio generation Acts as a latch If the value is 1 locked changes on the input pins are ignored This allows many changes to be made while the pin is locked and then introduced at one time by changing the pin back to 0 unlocked Sets the audio output level for this object A value of 0 0 indicates no volume a value of 1 0 represents maximum volume 1 A value of 1 suspends modeling of the emitter scan and pulse train A value of 1 mutes the audio output while continuing to model the emitter Duration of each pulse See Table 1 Fractional deviation from base PRI Period over which agility pattern repeats Number of pulses per agility step Maximum jitter applied to each pulse 12 See Table 17 Period of complete helical pattern including retrace Period of single rotation in azimuth Period of one revolution around the axis of rotation Width of primary scan motion Width of secondary scan motion The starting elevation of the scan pattern 142 Total number of bars in scan 1000 Time after reaching the maximum elevation that the scan requires before starting to scan again at the starting elevation Azimuth of the receiver relative to the Emitter Beam Reference Elevation angle of the receiver relative to the Emitter Beam Reference Power level at center o
5. AT Therefore the position of the antenna at any given time is 0 MT bo SimPhonics Incorporated Page 21 of 44 S B Emitter Audio 2 3 3 Unidirectional Sector A sector scan is similar to a circular scan but differs in that it only scans a portion of the sky rather than rotating in a full circle A unidirectional sector scan only scans in one direction in the Emitter Frame of Reference it starts at an azimuth of zero and scans to an azimuth equal to Sector Size It then restarts scanning at an azimuth of zero The rotation occurs at an elevation angle above the x y plane of the Emitter Frame of Reference Figure 13 depicts a conceptual view of a sector scan while Table 5 lists the additional input values that are required to model the scan Table 5 Unidirectional Sector Scan Parameters EAG Object Range Range Description Pin Name Min MLELE Scan Period ms Scan Period 1 10 100 000 Period of the sector scan including retrace time Sector Size deg Pattern Width 1 0 360 The width of the sector to be scanned Elevation deg Scan Elevation 90 90 Elevation of the scan Retrace Time ms Retrace Time 0 1000 The time it takes for a new sweep to start after the previous sweep has completed Figure 13 Sector Scan SimPhonics Incorporated Page 22 of 44 Emitter Audio Given the Scan Period t the Elevation o the current time t and the initial time the mod
6. 2438 2324 2553 2362 2400 time microseconds Figure 10 Jitter PRI Pattern SimPhonics Incorporated Page 16 of 44 CS Emitter Audio 2 3 Scan Pattern Modeling This section describes how the EAG object models scan patterns The purpose of scan pattern modeling is to determine the amplitude of the pulses generated by the pulse pattern modeling The amplitude of a pulse is proportional to the power of that pulse as it is perceived by the receiver The power of the pulse is affected by the position of the receiver relative to the lobes of the emitter Scan pattern modeling therefore must determine at any particular time which if any of the lobes of the emitter are illuminating the receiver Furthermore once an illuminating lobe has been identified the position of the receiver relative to the center of the lobe must be determined as power levels drop off away from the center The EAG object for any particular time determines where the center of the main lobe is pointing The positions of the other lobes are calculated relative to the main lobe according to the EAG object inputs as specified in Table 2 The receiver position is compared to the lobe positions to determine the current power level All these calculations take place in the Emitter Frame of Reference which is illustrated in Figure 11 Emitter Beam Reference Azimuth 0 Elevation 0 Receiver Main Beam hy Figure 11 Emitter Frame of Reference The Emitt
7. Pin Name Min Max Spiral Scan Period Scan Period 1 10 100 000 Time for a complete spiral scan pattern including the squint angle ranging from its maximum and decreasing to zero and including the retrace time Conical Scan Period ms Scan Period 2 10 100 000 Time for one revolution around the axis of rotation Max Squint Angle deg Pattern Width 1 0 45 Maximum angle between the axis of rotation and the emitter beam Retrace Time ms Retrace Time 0 1000 The time it takes for a new sweep to start after the previous sweep has completed Figure 15 Spiral Scan SimPhonics Incorporated Page 26 of 44 Emitter Audio Given the Conical Scan Period t the Spiral Scan Period x the current time t and the initial time the model started emitting to the time within the cycle is determined by tia t to mod Ti D t to mod T2 The time to complete the scanning portion of the cycle i e not including the retrace is determined by tretrace T2 Retrace Time If the time within the cycle is within the retrace period the emitter is not transmitting if ti 2 gt tretrace then Received Power 0 Otherwise the rate of rotation of the antenna around the axis of rotation is A zs An 0 A TI The squint angle varies between the maximum 42 and zero within the time of the scanning portion of the cycle tretrace The rate the squint angle changes is calculated as foll
8. greater than half the Sector Scan period then the antenna has reversed direction and the time within the sector sweep is adjusted as follows if ti gt 7 2 then tii Tim tit The current axis of rotation is defined by A Sector Size 0 2A T axis mb axis Do The conical movement of the antenna is defined by A 2 T W Aalt Squint Angle Then the position of the antenna at any given time is 0 Oaxis 5 COs ati 2 axis sin ti 2 SimPhonics Incorporated Page 34 of 44 e B Emitter Audio 2 3 11 Palmer Raster A Palmer Raster scan consists of an emitter beam that follows a conical scan superimposed on a Raster scan pattern The major motion of the scan is the Raster component of the scan which defines the motion of the axis of rotation of the conical component Figure 19 illustrates the typical pattern that results from a Palmer Raster scan Table 13 lists the additional input values that are required to model the Palmer Raster scan This scan requires two scan periods to be specified The Sweep Period defines the time for a single sweep i e the time to sweep through one bar of the raster pattern plus the retrace time while the Conical Scan Period defines the time for a single revolution around the axis of rotation Table 13 Palmer Raster Scan Parameters EAG Object Range Range Description Pin Name Min Max Sweep Period ms Scan Period 1 10 100 000 Peri
9. interval in us over which any pulse may be jittered A value of zero specifies no jitter A value greater than zero results in jitter applied to every pulse The EAG object checks the supplied Jitter Range to ensure that it is not possible for pulses to overlap overtake or undertake other pulses due to jitter This is accomplished by limiting the value of Jitter Range as follows Jitter Range lt Minimum Pulse Interval 2 Pulse Width The Minimum Pulse Interval is the smallest pulse interval that is possible disregarding jitter under the current PRI Agility Type and PRI input values An example of the effect of jitter on a single pulse is shown in Figure 9 It assumes a Jitter Range of 256 us The initial pulse on this diagram is shown at its nominal start time that is the start time calculated without considering jitter The pulse repetition interval is assumed to be 2438 us Pulse B represents the nominal start time of the next pulse which is 2438 us after the nominal start time of the initial pulse The actual next pulse is then randomly determined to occur anywhere from the possible pulses at A and C time microseconds Jitter Range Figure 9 Jitter Range SimPhonics Incorporated Page 15 of 44 Emitter Audio Considering the same example over several pulses Figure 10 shows one possible sequence of 6 pulses Whereas the pulse repetition interval is 2438 us the actual inter pulse intervals vary randomly
10. Deviation input value The overall pattern repeats every PRI Agility Period us The PRI Agility Deviation input value is interpreted relative to the PRI O value to calculate the minimum and maximum pulse interval values as follows Minimum Pulse Interval PRIO 1 PRI Agility Deviation 2 Maximum Pulse Interval PRIO 1 PRI Agility Deviation 2 For example a PRI Agility Deviation of 0 5 results in the pulse interval varying from 0 75 times PRI 0 to 1 25 times PRI 0 PRI Agility Period f Pulse Interval PRI Agility Deviation time microseconds Figure 7 Triangle PRI Agility Pattern SimPhonics Incorporated Page 13 of 44 Emitter Audio 2 2 10 Sine The Sine Agility type is based on the value of PRI 0 All other PRI values are ignored The pulse intervals between pulses follow a sine pattern as shown in Figure 8 They increase from a minimum value to a maximum value in a sinusoidal pattern and then gradually decrease from the maximum value back down to the minimum value The process then repeats The value of PRI 0 is half way between the minimum and maximum pulse interval The difference between the minimum and maximum pulse interval is defined by the PRI Agility Deviation input value The overall pattern repeats every PRI Agility Period ps The PRI Agility Deviation input value is interpreted relative to the PRI 0 value to calculate the minimum and maximum pulse interval values as follows Mi
11. Emitter Audio 3 2 EAG Object Output Pin The EAG object detects and reports invalid input values using the Error output pin If nonzero the Error output indicates which input value is invalid as specified in Table 19 Only the first detected error is reported When an error exists no audio is produced Table 19 EAG Object Error Codes Input Value Code Input Value Code Input Value Code Input Value 26 51 76 On Off PRI 19 Pulses Per Step SL Power Right 1 Lock 27 PRI 20 Jitter Range 77 SL Power Right 2 Volume 28 PRI 21 Main Power 78 SL Power Right 3 Pause 29 PRI 22 Main BW 79 SL Power Right 4 Mute 30 PRI 23 SL Offset Left 1 80 SL Power Right 5 Pulse Width 31 PRI 24 SL Offset Left 2 81 SL Power Right 6 PRI O 32 PRI 25 SL Offset Left 3 82 SL Power Right 7 PRI 1 33 PRI 26 SL Offset Left 4 83 Back Power PRI 2 34 PRI 27 SL Offset Left 5 84 Back BW PRI3 35 PRI 28 SL Offset Left 6 85 Scan Type PRI 4 36 PRI 29 SL Offset Left 7 86 Scan Period 1 PRI5 37 PRI 30 SL Power Left 1 87 Scan Period 2 PRI 6 38 PRI 31 SL Power Left 2 88 Scan Period 3 PRI 7 39 PRI 32 SL Power Left 3 89 Pattern Width 1 PRI 8 40 PRI 33 SL Power Left 4 90 Pattern Width 2 PRI 9 41 PRI 34 SL Power Left 5 91 Scan Elevation PRI 10 42 PRI 35 SL Power Left 6 92 No Of Bars PRI 11 43 PRI 36 SL Power Left 7 93 Retrace Time PRI 12 44 PRI 37 SL Offset Right 1 94 Azimuth PRI 13 45 P
12. RI 38 SL Offset Right 2 95 Elevation PRI 14 46 PRI 39 SL Offset Right 3 PRI 15 47 PRI 40 SL Offset Right 4 PRI 16 48 PRI Agility Type SL Offset Right 5 PRI 17 49 PRI Agility SL Offset Right 6 PRI 18 50 PRI Agility Period SL Offset Right 7 3 3 EAG Object Static Data There are two static data elements associated with the EAG object The first is the Channel which specifies of the audio output device channel number This number is assigned by the Platform Configure dialog box in the V Run Time System and indicates which audio output device is used for playing the audio stream The second static data element is called Algorithm and is used to specify which algorithm ID to use in processing Only one such algorithm currently exists and its ID is 1 SimPhonics Incorporated Page 43 of 44 be Emitter Audio 4 Definition of Terms Table 20 provides a list of terms used in this document and describes their meaning Table 20 Definition of Terms Term AC Alternating Current CW Continuous Wave dB Decibel DC Direct Current deg Degrees EAG Emitter Audio Generator KHz KiloHertz ms Milliseconds PRI Pulse Repetition Interval us Microseconds SimPhonics Incorporated Page 44 of 44
13. User s Manual SimPhonics Copyright 2006 SimPhonics Incorporated CR Emitter Audio TABLE OF CONTENTS 1 LE E s ER 5 1 1 Trademarks and Copyrights aaaa2aaanaxnaannn nnunnnnnnnnnnnnnnnunnnnnunnnnnnnnnnnnnnnnnnnnnna 5 1 2 Revision HIStory cccecceeeseeeeeeeeeeeeeeeeeeeeseeesesneee Error Bookmark not defined 5 1 3 Before Reading This Document aaaaaaaaavnannvunnuununnnnnnnnnnnnnnnnnnnnnnnnnnnnnunnnnua 5 1 4 RES ii 5 2 Emitter Audio Generator Object Functionality 6 2 1 Audio Generation Algorithm aaaaaaaaavaannvaanunnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnunnnnna 6 2 2 Pulse Pattern Modeling wa AAA AAA AUA AAA AUNA ENER ENER ENER En 8 2 2 1 Pulse Repetition Intervals and Stagger ERKENNEN ENER ENER EN ERR ENE REENEN EN 9 2 2 2 Pulse GrOUP IAA 9 2 2 3 Discrete PRI ui 10 2 2 4 SWITCH ON SCAN Aaa 10 2 2 5 PRI Slaa 10 2 2 6 CONTINUOUS Wave aaa 11 2 2 7 Up Ramp c a l N ANA RRR RRR RRR 11 2 2 8 DOWN RAMP maai 12 2 2 9 Triangle ii ges eE SE NENNEN SE REESEN RENE EEN RENE SEN ER EN EE e Ne EE Ce 13 2 2 10 ET 14 2 2 11 Pulses Per Step AAA 14 2 2 12 DCO a a E 15 2 3 Scan Pattern MOM Ga 17 2 3 1 dE TTC dE VEER 20 SA WR e Te TUTE 21 2 3 3 Unidirectional Sector wA 22 2 3 4 Bidirectional Sector AA 24 2 3 5 aaa 25 2 3 6 SPI Als eek iege eeereegekegeeeg eer caves cnddadaWseessesseavercedsossevesccuuseswoscscussensewes 26 2 3 7 ED AA 28 2 3 8 Helical sirsie ENEE ENER 30 2 3 9 Palmer Unisector
14. a certain period The algorithm ensures that the audio buffer does not run out of audio samples before it can be refilled It checks the remaining audio data in the buffer against a low water mark If there is less data in the buffer than the low water mark then additional SimPhonics Incorporated Page 6 of 44 CS Emitter Audio data is placed into the buffer up to the high water mark Additionally previously generated but not yet played audio data may be overwritten by new data if a significant change to the object s inputs has occurred A significant change is one which would perceptibly alter the audio already in the buffer Upon each execution of an EAG object the algorithm first checks whether the inputs of the EAG object have changed If the change is a major change like a change in scan pattern then the algorithm resets its state to restart modeling of the emitter If the change is minor like a receiver position update the new data is simply incorporated into the current modeling of the emitter A minor change is then further characterized as significant or not significant as described in the previous paragraph After dealing with any input changes if audio data needs to be generated the algorithm proceeds to determine the audio samples for the period in question Many of the input parameters of the EAG object are taken into account to generate the audio samples The algorithm models these parameters to determine th
15. aa 32 2 3 10 Palmer Bisector ii 34 2 3 11 Palmer Rain ii aa 35 2 3 12 Palmer Helical ccccccccccssesseeseeceeeeeeeeeeeceeseeneeeeeeeeaaeaseaaeasenseaeenseasensensens 37 2 3 13 Vertical Unidirectional Sector aaaa2aaaanxnaannnnnnunnunnnununnnunnunnunnnnnnnnnunnnnnnn 39 3 Emitter Audio Generator Object Interface 40 3 1 EAG Object Input PIO S A AAA AAA AAA AAA AAA AAA KAKAA AKAA AKAWA 41 3 2 EAG Object Output Pin iii Aa 43 3 3 EAG Object Static Data aaaaaaaaavaanvunnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 43 4 Definition OF TMS Ia 44 SimPhonics Incorporated Page 2 of 44 CS Emitter Audio LIST OF FIGURES Figure 1 Single PRI Value R RR EK KREE RE RE RE RE RE KE ENER kinakana kandaraan anakaa skian KEEN E en 9 Figure 2 Multiple PRI Values Stagger aaaaaaaazavaanaanununnnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnnnnnnnunnnnnnn anna 9 Figure 3 Discrete PRI Agility Pattern aaaaaaaaaaaaaaaaaaanunnnnnnnnnunnnunnnnnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnn 10 Figure 4 PRI Staircase Agility Pattern aaaaaaaazaaaanaannnannnnnnnnunnnnnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnunnun 10 Figure 5 Up Ramp PRI Agility Pattern aaaaaaaaaaaaaaaananannnnnannunnnnnnnnnnnnnnnnnnnnnnnunnunnnnnnnnunnnunnun 11 Figure 6 Down Ramp PRI Agility Pattern aa2aaaaaaaaanvannnnnunnnnnnnnnnnnnnunnnnnnnnunnnnnnnnnnnnnnnnnnnn 12 Figure 7 Triangle PRI Agility Pattern aaaaaaaaaznaanannunnnnnnnnnunnnunnnnnnnnnnnnnnnnnn
16. as follows Ay 2 T mm Aj t And the helical elevation rate is determined as follows A Vertical Extent O2 Ao tretrace Then the axis of rotation is given by Oaxis oti Maxis Po ob The conical movement of the antenna is calculated as follows A3 At O3 A3 T3 Squint Angle Then the position of the antenna at any given time is 0 Baxis 5 COS ast 3 daxis 8 SIN 3t 3 SimPhonics Incorporated Page 38 of 44 B Emitter Audio 2 3 13 Vertical Unidirectional Sector A vertical unidirectional sector scan is similar to a unidirectional sector scan but differs in that it scans vertically instead of horizontally Table 15 lists the additional input values that are required to model the scan Figure 21 depicts a conceptual view of a vertical unidirectional scan Table 15 Vertical Unidirectional Sector Scan Parameters Type EAG Object Range Range Description Name minimum maximum ms Scan Period 1 10 100 000 Period of the sector scan including retrace time Scan Period Sector Size deg Pattern Width 1 0 180 The height of the sector to be scanned Starting Elevation deg Scan Elevation 90 90 The starting elevation of the scan Retrace Time ms Retrace Time 0 1000 The time it takes for a new sweep to start after the previous sweep has completed Figure 21 Vertical Unidirectional Sector Scan SimPhonics Incorporated Page 39 of 44 e E
17. beam width of a side lobe All side lobes share the same beam width Table 3 Receiver Position Parameters EAG Object Range Range Description Pin Name Min Max Receiver Azimuth Azimuth 0 360 Azimuth of the receiver relative to the Emitter Beam Reference Receiver Elevation deg Elevation 90 90 Elevation of the receiver relative to the Emitter Beam Reference The audio amplitude of a pulse is calculated once the scan pattern modeling has determined the power level of the pulse according to the current receiver position and lobe positions The calculated power level of the pulse is a percentage of the power level that would result in maximum pulse amplitude in the audio signal no absolute power levels are used The main lobe power level P specified as a percentage is adjusted by the loss in power due to the receiver being in a side or back lobe L1 dB and by the loss in power due to the receiver not being centered in the lobe L2 dB as follows Calculated Power Level INVERSE_LOG L1 L2 20 P This calculated power level is linearly proportional to the amplitude of the pulse in the audio signal The following subsections define how each type of scan is modeled The input values particular to each scan type are identified and the equations for determining theta and phi are given For simplicity the equations are presented assuming that all input values are converted where
18. e Elevation Increment 4 the current time t and the initial time the model started emitting to the time within one sweep i e bar of the raster is determined by t t ty mod 7 The time to complete a single sweep i e not including the retrace is determined by tretrace T Retrace Time If the time within the sweep is within the retrace period the emitter is not transmitting if t gt tretrace then Received Power 0 Otherwise the rate of rotation of the antenna is calculated as follows A Sector Size O1 Aj tretrace and the current bar n within the raster pattern is determined by n Number of Bars tscan t to mod x nl n tsan Tid Note theO LG symbols denote an integer truncation of a real number Then the position of the antenna at any given time is 0 0 ti bon SimPhonics Incorporated Page 29 of 44 B Emitter Audio Ta 2 3 8 Helical A helical scan describes an emitter beam that rotates in a full circle in azimuth while its elevation increases continuously When the scan reaches its maximum elevation it returns to its starting elevation angle Figure 17 illustrates a helical scan while Table 10 lists the additional input values that are required to model the scan A helical scan requires two scan periods to be specified The Helical Scan Period defines the time for the entire scan while the Circular Scan Period defines the time for a single rotation i e in azimuth
19. e is being received at the sample time then the value of the sample is calculated according to the current received power and scaled to produce a physical output level within a range of 0 to 2 5 Volts peak to peak A further optimization is also implemented The current received power is not recalculated within a single pulse i e the first audio sample that is within a pulse determines the current received power for the entire pulse SimPhonics Incorporated Page 7 of 44 Emitter Audio 2 2 Pulse Pattern Modeling This section describes the pulse patterns that are generated by the EAG object The pulse waveform is rectangular with a variable pulse width The pattern of pulses is then defined by the interval between each pulse The calculation of pulse intervals is described in the following subsections The amplitude of each pulse is a consequence of the scan pattern Scan patterns are discussed in section 2 3 The modeling of pulse intervals depends on the value of the PRI Agility Type input The possible values for this input are shown in Table 1 Table 1 Agility Types Agility Type Off Pulse Group Discrete PRI Switch On Scan Staircase CW Up Ramp Down Ramp Triangle Sine WOWIOINIQIUIIR WIN IH O SimPhonics Incorporated Page 8 of 44 Emitter Audio 2 2 1 Pulse Repetition Intervals and Stagger When the Agility Type is set to Off the pulse intervals are determi
20. eir effects on the audio At a sample rate of 44 1 KHz the algorithm calculates a new sample at intervals of 22 7 microseconds us For any particular sample the algorithm determines where the center of the main beam of the emitter is pointing relative to the receiver at the sample time This is a function of the receiver azimuth and elevation relative to the emitter the scan pattern and any associated parameters such as scan period Next the algorithm determines which beam if any is illuminating the receiver and the resultant received power The current received power then becomes the basis of calculating the amplitude of the audio sample The algorithm also models the pulse train of emissions from the emitter This determines the points in time when pulses are received This is affected by the PRI inputs and agility inputs For example if an emitter has several PRI intervals defined then the received pulses occur at times corresponding to those intervals as opposed to one regular interval The final step to determine the current audio sample value combines the previously calculated current received power with the calculated pulse train The algorithm uses the pulse train to determine whether a pulse is being received at the receiver at the current sample time For this purpose the width of a pulse is fixed at 100 us If a pulse is not being received at the current sample time then the value of the sample is calculated as zero If a puls
21. el started emitting to the time within the cycle is determined by ti t ty mod 7 The time to complete the scanning portion of the cycle i e not including the retrace is determined by tretrace T1 Retrace Time If the time within the cycle is within the retrace period the emitter is not transmitting if t gt tretrace then Received Power 0 Otherwise the rate of rotation of the antenna which scans Sector Size degrees between 0 and tretrace seconds is calculated as follows A Sector Size mu A tretrace Then the position of the antenna at any given time is 0 o t bo SimPhonics Incorporated Page 23 of 44 e e Emitter Audio 2 3 4 Bidirectional Sector A bidirectional sector scan is similar to a unidirectional sector scan except that it scans in both directions In the Emitter Frame of Reference it starts at an azimuth of zero and scans to an azimuth equal to Sector Size It then scans in the opposite direction from an azimuth equal to Sector Size back to an azimuth of zero The rotation occurs at an elevation angle above the x y plane of the Emitter Frame of Reference Table 6 lists the additional input values that are required to model the scan Table 6 Bidirectional Sector Scan Parameters EAG Object Range Range Description Pin Name Min Mas Scan Period ms Scan Period 1 10 100 000 Period of the sector scan including both directions Secto
22. er Bisector Scan Parameters aaaaaaaannannnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnu 34 Table 13 Palmer Raster Scan Parameters mins ENK EE EE E KEE RRE NN KENE ENK EE EE ENKE E KREE KEN 35 Table 14 Palmer Helical Scan Parameters sasaaa nanunua nanunua KREE KENE ENK ENK EE ENKE E KIKI 37 Table 15 Vertical Unidirectional Sector Scan Parametere neue NNN ANE ENK EK KE E KK E KEN ENK NN 39 Table 16 EAG Object Left Side PiMS aaaaaaaaaaaanaaannunnnnunnnnnnnnnnnunnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnna 41 Table 17 TOWN TTT 42 Table 18 EAG Object Bottom P NS aaaaaa2aaaaaaaaanaaannnannnnnunnnnnnnnnnnnnnnnnnnnnnnnnunnnunnnnnnnnnnnnnnnnnnnnnnnna 42 Table 19 EAG Object Error Codes aaaaaaaaaaaaaaanaaannnnnnnunnnnnnnnnnnunnnnnnnnnnnnnnnunnnnnnnnnnnnunnunnnnnnnnnnna 43 Table 20 Definition Of TermS wicsisctesteiercnsecesniesenccsessnstscesnrecccacnssacusnedcssnenntnasstnavncecusseneansesane 44 SimPhonics Incorporated Page 4 of 44 Emitter Audio 1 Preface 1 1 Trademarks and Copyrights Any trademarks shown throughout this document are the property of their respective owners V and SMx are trademarks of SimPhonics Incorporated Ensure you have the latest release of this document before relying on this information Version Description Date 0 1 Pre release February 14 2006 1 0 Initial Release February 17 2006 1 1 Updated January 28 2009 This document was authored using Microsoft Word 2003 and is mainta
23. er Frame of Reference is the native coordinate system for the EAG object The emitter is located at the origin of the Emitter Frame of Reference The positive y axis is then defined as the Emitter Beam Reference The motion of the emitter main lobe or beam is modeled relative to the Emitter Beam Reference The location of the receiver in the Emitter Frame of Reference is as specified by the Receiver azimuth az and Receiver elevation el input values which are relative to the Emitter Beam Reference These input values are defined in Table 3 It is important to note that the Emitter Beam Reference does not necessarily coincide with the main beam of the emitter Instead the azimuth and elevation of the main beam at any time are defined as an azimuth and elevation relative to the SimPhonics Incorporated Page 17 of 44 Emitter Audio Emitter Beam Reference The azimuth and elevation of the main beam at time t are represented in the figure and in the following discussions by theta 0 and phi 9 It is the responsibility of the client of the EAG object to correctly locate the receiver in the Emitter Frame of Reference Table 2 Lobe Parameters EAG Object Range Range Description Pin Name Min Max Main Lobe Power dB Main Power 0 60 Power level at center of main lobe specified in dB down from maximum power i e 0 dB maximum power Main Lobe Beam Width de
24. er Helical SCan aa22aaaaaannxvnnnunnnunnnnnnnunnnnnnnunnunnnnnunnnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 37 Figure 21 Vertical Unidirectional Sector Scan aiana ENEE ERR esas sees AAA KUAKAA AKAA awa 39 Figure 22 Emitter Audio Generator Object aaaaaaaaaannaavannnnnunnnnnnnnnnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnn 40 SimPhonics Incorporated Page 3 of 44 CS Emitter Audio LIST OF TABLES Table 1 Agility TYPE saizi nwa akian rannus KUKAAA ER ENEE a a ENEE ERR 8 Table 2 LODE Patamu aaa 18 Table 3 Receiver Position ParameterS aaaaaaaaaaannnnnnnnnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnu 19 Table 4 Circular Scan Parameters 2aaaaaaaaaaaaaanannnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnannna 21 Table 5 Unidirectional Sector Scan Parametere ue ee EK E KK E KEN ANE NN KENE EE EE ENKE E ENER EN ENN 22 Table 6 Bidirectional Sector Scan Parametere nee KK KKK E KK E KEN ANE NN KENE EE EE E KEE RRE ENK NN na 24 Table 7 Conical Scan Parameters sssssausmmssenamengassnnennneensensnnenmanannananmeeaunsannmscennt 25 Table 8 Spiral Scan ParameterS aaaaaaaaaaaaaaanannnnnnnnnnnnnnnnunnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnunnnnnnnnnnnn 26 Table 9 Raster Scan Parameters IA 28 Table 10 Helical Scan Parameters see kk KENNEN KENE EE EE E KEE KREE EE ENK ENK ENK EE ENKE E KREE KEN na 30 Table 11 Palmer Unisector Scan Parametere ue NK EK EK E KK E KEN ANE ENK ENK EE EE E KEE RRE ENK NN na 32 Table 12 Palm
25. f main lobe specified in dB down from maximum power i e 0 dB maximum power The 3 dB beam width of the main lobe Power level relative to i e down from main lobe power The 3 dB beam width of the back lobe SimPhonics Incorporated Page 41 of 44 B Emitter Audio a Table 17 provides a list of acceptable values for the Scan Type pin Any other values are ignored and treated as 0 Table 17 Scan Types Input Scan Type Steady Circular Conical Unisector Bisector Raster Helical Palmer Helical Palmer Unisector Palmer Bisector Palmer Raster Spiral Vertical Unisector solo A eo Pro 4 N The pins along the bottom of the object are identified and described in Table 18 Table 18 EAG Object Bottom Pins EAG Object Units Range Range Description Pin Name Side Lobe Power Power level of left side lobes relative to i e down from Left 1 7 main lobe power Side Lobe Power Power level of right side lobes relative to i e down from Right 1 7 main lobe power Side Lobe Offset Position of right side lobes relative to main lobe specified Left 1 7 as an angle counter clockwise from the main lobe direction Position of left side lobes relative to main lobe specified as an angle clockwise from the main lobe direction Side Lobe Offset Right 1 7 SimPhonics Incorporated Page 42 of 44
26. g Main BW 0 30 The 3 dB beam width of the main lobe Back Lobe Power dB Back Power 0 60 Power level relative to i e down from main lobe power Back Lobe Beam Width deg Back BW 0 30 The 3 dB beam width of the back lobe Side Lobe Left 1 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Left 1 lobe specified as an angle counter clockwise from the main lobe direction Side Lobe Left 1 Power dB Side Lobe Power 0 60 Power level relative to i e down from Left 1 main lobe power Side Lobe Left 2 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Left 2 lobe specified as an angle counter clockwise from the main lobe direction Side Lobe Left 2 Power dB Side Lobe Power 0 60 Power level relative to i e down from Left 2 main lobe power Side Lobe Left 3 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Left 3 lobe specified as an angle counter clockwise from the main lobe direction Side Lobe Left 3 Power dB Side Lobe Power 0 60 Power level relative to i e down from Left 3 main lobe power Side Lobe Left 4 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Left 4 lobe specified as an angle counter clockwise from the main lobe direction Side Lobe Left 4 Power dB Side Lobe Power 0 60 Power level relative to i e down from Left 4 main lobe power Side Lobe Left 5 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Left 5 lobe spec
27. h the previous one The pulse interval between the last pulse of the pattern and the first pulse of the next repetition of the pattern is determined by the PRI Agility Period The EAG object ensures that this pulse interval is at least PRI 0 PRI Agility Period PRIO 2xPRI 0 3xPRI 0 4xPRI 0 less than 5xPRI 0 PRIO time microseconds Figure 4 PRI Staircase Agility Pattern SimPhonics Incorporated Page 10 of 44 Emitter Audio 2 2 6 Continuous Wave No audio is produced for this agility type 2 2 7 Up Ramp The Up Ramp Agility type is based on the value of PRI 0 All other PRI values are ignored The pulse intervals between pulses follow an up ramp pattern as shown in Figure 5 They gradually increase from PRI 0 us to a maximum value defined by the PRI Agility Deviation input value The maximum is reached after PRI Agility Period us The next pulse interval then drops back to PRI 0 us and the process repeats The PRI Agility Deviation input value is interpreted relative to the PRI O value to calculate the maximum pulse interval value as follows Maximum Pulse Interval PRIO 1 PRI Agility Deviation For example a PRI Agility Deviation of 0 5 results in the pulse interval varying from PRI 0 to 1 50 times PRI 0 t PRI Agility Period t PRI Agility Deviation Pulse Interval time microseconds Figure 5 Up Ramp PRI Agility Pattern SimPhonics Incorporated Page 11 of 44 Emitter Audio 2 2 8 Down Ra
28. ified as an angle counter clockwise from the main lobe direction Side Lobe Left 5 Power dB Side Lobe Power 0 60 Power level relative to i e down from Left 5 main lobe power Side Lobe Left 6 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Left 6 lobe specified as an angle counter clockwise from the main lobe direction Side Lobe Left 6 Power dB Side Lobe Power 0 60 Power level relative to i e down from Left 6 main lobe power Side Lobe Left 7 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Left 7 lobe specified as an angle counter clockwise from the main lobe direction Side Lobe Left 7 Power dB Side Lobe Power 0 60 Power level relative to i e down from Left 7 main lobe power Side Lobe Right 1 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Right 1 lobe specified as an angle clockwise from the main lobe direction Side Lobe Right 1 Power dB Side Lobe Power 0 60 Power level relative to i e down from Right 1 main lobe power Side Lobe Right 2 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Right 2 lobe specified as an angle clockwise from the main lobe direction Side Lobe Right 2 Power dB Side Lobe Power 0 60 Power level relative to i e down from Right 2 main lobe power Side Lobe Right 3 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Right 3 lobe specified as an angle clockwise from the main lobe directio
29. ined at the SimPhonics web site in DOC format This document may be copied freely for any purpose 1 2 Before Reading This Document The reader should be familiar with the V Visual Programming System in particular the use of objects The V Programming System User Manual is available from the Downloads area of our web site http www simphonics com supp downloads docs V is the language of which the Emitter Audio Generator is a part and is the only means of programming the emitter object s behavior The Emitter Audio Generator object is designed for use in advanced applications requiring basic knowledge radio emitters 1 3 References SimPhonics Home Page _http www simphonics com Amazingly Simple Se nn sites Simply Amazing SimPhonics Incorporated Page 5 of 44 Emitter Audio 2 Emitter Audio Generator Object Functionality The Emitter Audio Generator object is a part of the V library It consists of a large number of inputs which define the characteristics of a single emitter The EAG object generates audio according to these dynamic inputs The inputs are On Off to enable and disable audio generation Lock to indicate when input values are being changed Volume Pause to suspend modeling of the emitter scan and pulse train Mute to silence audio output while continuing to model the emitter Pulse Width PRI 0 through PRI 40 PRI Agility Type PRI Agility Deviation PRI Agility Period Pulses Per Ste
30. mitter Audio 3 Emitter Audio Generator Object Interface The Emitter Audio Generator Object shown in Figure 22 uses input pins output pins and static data to control and configure its operation The sections that follow identify and describe these data in terms of units range and functionality 0123 4 5 6 7 8 910111213 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Error EMMITER AUDIO GENERATOR PRl gilityType PRlgilityDeviation PRl gility Period PulsesPer Sep San Hevation No of Bars Retrace Time Azimuth Ide Lobe power Sde Lobe Offsets Left Right Left Right 1234 5 67 1234567 1234567 423 45 6 Tf Figure 22 Emitter Audio Generator Object SimPhonics Incorporated Page 40 of 44 Emitter Audio 3 1 EAG Object Input Pins Across the top of the object are pins labeled with numbers from 0 to 40 These pins are used to set the Pulse Repetition Intervals PRI Units for these pins are provided in microseconds us See section 2 2 for more details The pins along the left side of the object are identified and described in Table 16 EAG Object Pin Name On Off Lock Volume Pause Mute Pulse Width PRI Agility Type PRI Agility Deviation PRI Agility Period Pulses Per Step Jitter Range Scan Type Scan Period 1 Scan Period 2 Scan Period 3 Pattern Width 1 Pattern Width 2 Scan Elevation No of Bars Retrace Time Azimuth Elevation Main Power
31. mp The Down Ramp Agility type is based on the value of PRI 0 All other PRI values are ignored The pulse intervals between pulses follow a down ramp pattern as shown in Figure 6 They gradually decrease from PRI 0 us to a minimum value defined by the PRI Agility Deviation input value The minimum is reached after PRI Agility Period us The next pulse interval then jumps back to PRI O us and the process repeats The PRI Agility Deviation input value is interpreted relative to the PRI O value to calculate the minimum pulse interval value as follows Minimum Pulse Interval PRIO 1 PRI Agility Deviation For example a PRI Agility Deviation of 0 25 results in the pulse interval varying from PRI 0 to 0 75 times PRI 0 PRI Agility Period f Pulse Interval PRI Agility Deviation time microseconds Figure 6 Down Ramp PRI Agility Pattern SimPhonics Incorporated Page 12 of 44 B Emitter Audio 2 2 9 Triangle The Triangle Agility type is based on the value of PRI 0 All other PRI values are ignored The pulse intervals between pulses follow a triangle pattern as shown in Figure 7 They gradually increase from a minimum value to a maximum value and then gradually decrease from the maximum value back down to the minimum value The process then repeats The value of PRI 0 is half way between the minimum and maximum pulse interval The difference between the minimum and maximum pulse interval is defined by the PRI Agility
32. n Side Lobe Right 3 Power dB Side Lobe Power 0 60 Power level relative to i e down from Right 3 main lobe power Side Lobe Right 4 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Right 4 lobe specified as an angle clockwise from the main lobe direction SimPhonics Incorporated Page 18 of 44 Table 2 Lobe Parameters EAG Object Range Range Description Pin Name Min WERE Side Lobe Right 4 Power dB Side Lobe Power 0 60 Power level relative to i e down from Right 4 main lobe power Side Lobe Right 5 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Right 5 lobe specified as an angle clockwise from the main lobe direction Side Lobe Right 5 Power dB Side Lobe Power 0 60 Power level relative to e down from Right 5 main lobe power Side Lobe Right 6 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Right 6 lobe specified as an angle clockwise from the main lobe direction Side Lobe Right 6 Power dB Side Lobe Power 0 60 Power level relative to i e down from Right 6 main lobe power Side Lobe Right 7 Offset deg Side Lobe Offset 0 180 Position of side lobe relative to main Right 7 lobe specified as an angle clockwise from the main lobe direction Side Lobe Right 7 Power dB Side Lobe Power 0 60 Power level relative to i e down from Right 7 main lobe power Side Lobe Beam Width deg Side BW 0 30 The 3 dB
33. ned by the Pulse Repetition Interval input values PRI 0 PRI 1 PRI 40 The EAG object takes the PRI values into account only until it encounters an input value of zero After the first zero value the remaining PRI inputs are ignored Each non zero PRI value defines the interval in us to the next pulse The effect of different PRI input values is shown in the following figures Figure 1 shows the pulse pattern resulting from a single PRI value of 2438 us i e PRI 0 2438 PRI 1 0 The start of each pulse is 2438 us after the start of the previous pulse The resulting audio has a frequency of 410Hz i e 410 1 0 002438 2438 2438 2438 2438 2438 time microseconds Figure 1 Single PRI Value Figure 2 shows the pulse pattern resulting from a sequence of 4 PRI values e PRI 0 3048 PRI 1 1524 PRI 2 4267 PRI 3 2134 PRI 4 0 This is also known as a 4 level stagger The interval between pulses varies according to the sequence of PRI values 3048 1524 4267 2134 3048 time microseconds Figure 2 Multiple PRI Values Stagger 2 2 2 Pulse Group The Pulse Group Agility type creates a pulse pattern that repeats at an interval of PRI 0 The individual pulse intervals are then defined by the subsequent PRI input values i e PRI 1 PRI 2 etc In the case where the individual pulse intervals define a pattern whose period exceeds that of PRI 0 the pattern is truncated to ensure that the overall period is equal
34. nimum Pulse Interval PRIO 1 PRI Agility Deviation 2 Maximum Pulse Interval PRIO 1 PRI Agility Deviation 2 For example a PRI Agility Deviation of 0 5 results in the pulse interval varying from 0 75 times PRI 0 to 1 25 times PRI 0 PRI Agility Period PRI Agility Deviation Pulse Interval time microseconds Figure 8 Sine PRI Agility Pattern 2 2 11 Pulses Per Step The discussions of the PRI Staircase Up Ramp Down Ramp Triangle and Sine agility types assumed that the Pulses Per Step input value was one If this is not the case then the pulse patterns generated by these agility types are as previously described except that the pulse interval changes only after the number of pulses specified by the Pulses Per Step input value SimPhonics Incorporated Page 14 of 44 CS Emitter Audio 2 2 12 Jitter The EAG object supports jitter in combination with any PRI Agility Type Jitter is random adjustment of pulse intervals over a maximum range defined by the Jitter Range input value The start of each pulse is first determined according to the methods discussed previously A delta time is then added to the start time to determine the actual start time of the pulse The delta time can be negative or positive and is randomly determined for each pulse The absolute value of the delta time is less than or equal to half the Jitter Range input value The Jitter Range input value specifies the maximum time
35. nt O2 Ao tretrace Then the position of the antenna at any given time is 0 mb bo azti 2 SimPhonics Incorporated Page 31 of 44 B Emitter Audio 2 3 9 Palmer Unisector A Palmer scan consists of an emitter beam that follows a conical scan superimposed on a circular scan pattern The major motion of the scan is the circular component The emitter beam rotates continuously in azimuth while the conical motion is superimposed In effect the circular component of the scan defines the motion of the axis of rotation of the conical component Figure 18 illustrates the typical pattern that results from a Palmer scan A Palmer Unisector scan is a Palmer scan as described above except that only a certain sector in azimuth is scanned during each sweep This corresponds to a conical scan superimposed on a unidirectional sector scan Table 11 lists the additional input values that are required to model the pa mer unisector scan This scan requires two scan periods to be specified The Sector Scan Period defines the time for the entire scan i e the time to sweep through the sector plus the retrace time while the Conical Scan Period defines the time for a single revolution around the axis of rotation Table 11 Palmer Unisector Scan Parameters EAG Object Range Range Description Pin Name Min Max Sector Scan Period Scan Period 1 10 100 000 Period to complete one sweep of the sector including retrace Sec
36. nunnnnnnnnnnnnnnnnnnnn 13 Figure 8 Sine PRI Agility Pattern aaaaaaaaaaaaaaavnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnnnnun 14 Figure 9 Jitter Rang aaaaaaaxaaaaaaaaaannannnnnnnnnnnnnnnnnnnnnnnunnnnnnnnnunnnnnunnnnnnnnnnunnnunnnnnnnnnnnnnnnnnnnnnnnnnum 15 Figure 10 Jitter PRI Pattern waa AAA RENE RE KEEN KAKAA AKAA KA AUNA AAA KAKAA KAKAA ER E en 16 Figure 11 Emitter Frame of ReferenC axzaaaaxaanznuxannannnnnnnnnununnnnnnnnnnnnnunnnnnnnnnunnnnnnnnnunnnnnnnnnn 17 Figure 12 Circular Scan aaaaaaaazaaannannunnnunnnnnnnnnunnnnnnnnnunnnnnnnnnnnunnnunnnnnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnna 21 Figure 13 Sector SCAM aaaaaaaaanaaaaaaavnnunnnnnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 22 Figure 14 Comical SCan aaaaxaaaaaaannuannnnnnnnnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnunnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnna 25 Figure 15 Spiral Scan aazaaaaazananaaannnnnnnnnunnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnunnnnnnnnnnnunnnnn nna 26 Figure 16 Raster Scan EE ERR R KREE EE kannan KAA KAA WANAWANIA KIWA KIKA RERE NEE ER EN en 28 Figure 17 Helical SCAN umaana aaa AAA AAA AAA AAA KEEN ENEE ENEE AAA AAA AAA AAA AAA AKAA Aaaa 30 Figure 18 Palmer Scan aaaaaaaaaaaaaaaaanannnnnnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnunnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnnnnnn 32 Figure 19 Palmer Raster SCan zaaazaaaaaaaanaananannnunnnnnnnunnnnnnnnnnnnnnnunnnnnnnnnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 35 Figure 20 Palm
37. od of one bar of the raster including retrace time Sector Size deg Pattern Width 1 0 360 The width of the sector to be scanned Number of Bars No Of Bars 2 12 Total number of bars in scan Elevation Increment deg Scan Elevation 0 45 Elevation delta between bars Retrace Time ms Retrace Time 0 1000 Time after completing a bar that the scan requires to start the next bar Conical Scan Period ms Scan Period 2 10 100 000 Period of one revolution around the axis of rotation Squint Angle deg Pattern Width 2 0 45 Angle between the axis of rotation and the emitter beam Figure 19 Palmer Raster Scan SimPhonics Incorporated Page 35 of 44 Emitter Audio Given the Sweep Period t the Conical Scan Period t2 the Elevation Increment 4 the current time t and the initial time the model started emitting to the time within one sweep i e bar of the raster is determined by tia t to mod Ti The time to complete a single sweep i e not including the retrace is determined by tretrace T Retrace Time If the time within the sweep is within the retrace period the emitter is not transmitting if tii gt tretrace then Received Power 0 Otherwise the rate of rotation of the raster component is defined by A Sector Size o Aj tretrace and the current bar n within the raster pattern is determined by n Number of Bars tscan t e to mod TI Nb n L tscan t
38. ows A Max Squint Angle O2 Ao tretrace Then the position of the antenna at any given time is D D 0 cos ati 1 d 6 sin ytis SimPhonics Incorporated Page 27 of 44 e S B Emitter Audio 2 3 7 Raster A raster scan covers a segment of the sky in azimuth like a sector scan but its elevation changes from sweep to sweep At each sweep the elevation of the beam is increased The sweeps of the scan are known as bars After the scan completes its designated number of bars it starts all over again at the first bar Figure 16 illustrates a raster scan while Table 9 lists the additional input values that are required to model the scan The lower left hand corner of the raster scan pattern is defined to coincide with the Emitter Beam Reference Table 9 Raster Scan Parameters EAG Object Range Range Description Pin Name Min MELE Sweep Period Scan Period 1 100 000 Period of one bar of the raster including retrace time Sector Size deg Pattern Width 1 0 360 The width of the sector to be scanned Number of Bars No of Bars 2 12 Total number of bars in scan Elevation Increment deg Scan Elevation 0 45 Elevation delta between bars Retrace Time ms Retrace Time 0 1000 Time after completing a bar that the scan requires to start the next bar Figure 16 Raster Scan SimPhonics Incorporated Page 28 of 44 Emitter Audio Given the Sweep Period t th
39. p Jitter Range Main Lobe Power Main Lobe Beam Width Side Lobe Left 1 Offset through Side Lobe Left 7 Offset Side Lobe Left 1 Power through Side Lobe Left 7 Power Side Lobe Right 1 Offset through Side Lobe Right 7 Offset Side Lobe Right 1 Power through Side Lobe Right 7 Power Back Lobe Power Back Lobe Beam Width Scan Type Scan Period 1 Scan Period 2 and Scan Period 3 Pattern Width 1 and Pattern Width 2 Scan Elevation No of Bars Retrace Time Receiver Azimuth and Elevation relative to the Emitter frame of reference The EAG object also takes into account the following static inputs e Algorithm ID e Audio Device Number Static inputs are defined in the V model before runtime The Algorithm ID specifies the audio generation algorithm that is used Only one such algorithm currently exists The Audio Device Number indicates which audio channel is used to produce the audio 2 1 Audio Generation Algorithm This section describes the algorithm that is used by an EAG object to produce an audio stream The audio generation algorithm produces 16 bit digital audio at a 44 1 KHz sampling rate The audio generation algorithm executes within each EAG object at the rate defined by the V Run Time System It takes into account the current inputs of the EAG object and the current state of the emitter represented by that object At each frame the algorithm may generate audio samples starting at some point in the future and continuing for
40. r Audio 2 3 10 Palmer Bisector A Palmer Bisector scan is similar to a Palmer Unisector except that it scans in both directions This corresponds to a conical scan superimposed on a bidirectional sector scan Table 12 lists the additional input values that are required to model the palmer bisector scan This scan requires two scan periods to be specified The Sector Scan Period defines the time for the entire scan i e the time to sweep through the sector in both directions while the Conical Scan Period defines the time for a single revolution around the axis of rotation Table 12 Palmer Bisector Scan Parameters EAG Object Range Range Description Pin Name Min Sector Scan Period ms Scan Period 1 10 100 000 Period to complete one sweep of the sector in both directions Sector Size deg Pattern Width 1 0 360 The width of the sector to be scanned Conical Scan Period ms Scan Period 2 10 100 000 Period of one revolution around the axis of rotation Squint Angle deg Pattern Width 2 0 45 Angle between the axis of rotation and the emitter beam Elevation deg Scan Elevation 90 90 Elevation of the scan Given the Sector Scan Period t the Conical Scan Period 12 the Elevation bo the current time t and the initial time the model started emitting to the time within the sweep is determined by tia t to mod Ti D t to mod T2 If the time within the sector sweep is
41. r Size deg Pattern Width 1 0 360 The width of the sector to be scanned Elevation deg Scan Elevation 90 90 Elevation of the scan Given the Scan Period t the Elevation o the current time t and the initial time the model started emitting to the time within the cycle is determined by t t to mod Ti If the time within the cycle is greater than half the scan period then the antenna has reversed direction and the time within the cycle is adjusted as follows if t gt t 2 then t Tu t The rate of rotation of the antenna which scans Sector Size degrees between 0 and 171 2 seconds is calculated as follows A Sector Size 0 2 A t Then the position of the antenna at any given time is 0 0 ti EEN SimPhonics Incorporated Page 24 of 44 B Emitter Audio 3 2 3 5 Conical A conical scan describes an emitter which scans towards a fixed direction in space Rather than pointing directly at the required direction a conical scan rotates around that vector keeping the area of interest at the center of the scan The angle between the axis of rotation and the cone is called the squint angle Figure 14 illustrates a conical scan while Table 7 lists the additional input values that are required to model the scan The axis of rotation of the conical scan is defined to coincide with the Emitter Beam Reference Table 7 Conical Scan Parameters EAG Object Range Range Description Pin Name Min Max
42. required to radians and seconds SimPhonics Incorporated Page 19 of 44 Emitter Audio 2 3 1 Fixed Steady A Fixed or Steady scan describes an emitter whose main beam points in a fixed direction No additional input values are required to model this scan type The main beam is defined to coincide with the Emitter Beam Reference as follows 0 0 0 SimPhonics Incorporated Page 20 of 44 B Emitter Audio 3 2 3 2 Circular The Circular scan describes an emitter whose antenna rotates in a full circle The rotation occurs at an elevation angle above the x y plane of the Emitter Frame of Reference The Emitter Beam Reference or positive y axis defines the starting position of the scan at time zero Figure 12 depicts a conceptual view of a circular scan while Table 4 lists the additional input values that are required to model the scan Table 4 Circular Scan Parameters EAG Object Range Range Description Pin Name Min Mas Scan Period ms Scan Period 1 10 100 000 Period of one full rotation of the antenna Elevation deg Scan Elevation 90 90 Elevation of the scan Figure 12 Circular Scan Given the Scan Period t the Elevation o the current time t and the initial time the model started emitting to the time within the cycle is determined by ti t to mod 7 Since the pattern width is a full circle A 27 The rate of rotation of the antenna is calculated as ol
43. to PRI 0 SimPhonics Incorporated Page 9 of 44 Emitter Audio 2 2 3 Discrete PRI The Discrete PRI Agility type generates a pattern of pulses whose pulse interval changes periodically Figure 3 illustrates how the pulse repetition interval varies The interval changes according to the PRI Agility Period input value and follows the sequence of defined PRI values In the example the interval starts at PRI 0 for the length of the PRI Agility Period then changes to PRI 1 for another PRI Agility Period changes to PRI 2 for another PRI Agility Period and then finally returns to PRI 0 at which point the whole cycle repeats The example assumes that the PRI 3 input value is set to zero to indicate the end of the cycle PRI Agility Period t PRI Agility Period t PRI Agility Period f PRIO PRI 2 PRI 1 Pulse Interval gt time microseconds Figure 3 Discrete PRI Agility Pattern 2 2 4 Switch on Scan No audio is produced for this agility type 2 2 5 PRI Staircase The PRI Staircase Agility type is based on the value of PRI 0 All other PRI values are ignored The pattern of pulses generated is shown in Figure 4 The pattern repeats with a period defined by PRI Agility Period The first pulse occurs at the start of the pattern The second pulse occurs at PRI 0 us later The third pulse occurs at 2 times PRI 0 us after the second pulse The pulse interval for each subsequent pulse increases by PRI 0 us compared wit
44. tor Size deg Pattern Width 1 0 360 The width of the sector to be scanned Retrace Time ms Retrace Time 0 1000 The time it takes for a new sweep to start after the previous sweep has completed Conical Scan Period ms Scan Period 2 10 100 000 Period of one revolution around the axis of rotation Squint Angle deg Pattern Width 2 0 45 Angle between the axis of rotation and the emitter beam Elevation deg Scan Elevation 90 90 Elevation of the scan Figure 18 Palmer Scan SimPhonics Incorporated Page 32 of 44 Emitter Audio Given the Sector Scan Period t the Conical Scan Period 12 the Elevation o the current time t and the initial time the model started emitting t0 the time within the sweep is determined by tia t to mod Ti D t to mod T2 The time to complete a single sweep e not including the retrace is determined by tretrace Ti Retrace Time If the time within the sweep is within the retrace period the emitter is not transmitting if ti gt tretrace then Received Power 0 Otherwise the current axis of rotation is defined by A Sector Size o Aj tretrace Baxis oti 1 axis du The conical movement of the antenna is defined by A 2 FE 2 Aalt 6 Squint Angle Then the position of the antenna at any given time is 0 Oasis 6 cos ti 2 daxis 8 sin ati 2 SimPhonics Incorporated Page 33 of 44 e Emitte
45. uding retrace Vertical Extent deg Pattern Width 1 0 180 Maximum elevation angle relative to the starting elevation Circular Scan Period ms Scan Period 2 10 100 000 Period of single rotation in azimuth Retrace Time ms Retrace Time 0 1000 Time after reaching the maximum elevation that the scan requires before starting to scan again at the starting elevation Starting Elevation deg Scan Elevation 90 90 The starting elevation of the scan pattern Conical Scan Period ms Scan Period 3 10 100 000 Period of one revolution around the axis of rotation Squint Angle deg Pattern Width 2 0 45 Angle between the axis of rotation and the emitter beam Figure 20 Palmer Helical Scan SimPhonics Incorporated Page 37 of 44 Emitter Audio Given the Circular Scan Period Ceci the Helical Scan Period t2 the Conical Scan Period 13 the Starting Elevation o the current time t and the initial time the model started emitting to the time within each cycle is determined by tia t to mod Ti ti 2 t to mod T2 D t to mod T3 The time to complete the scanning portion of the helical pattern i e not including the retrace is determined by tretrace T Retrace Time If the time within the cycle is within the retrace period the emitter is not transmitting if ti 2 gt tretrace then Received Power 0 Otherwise the helical circular rate of rotation is calculated

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