(NASA-TN-t.-7496) AVEEiGE DAILY VARIAilONS H74-17 120 IN THE IYACSETLC FIELD AS CBSEEVED BY AT.5-5 fX'JF,) 1'. p HC 83.25 CSCL 04A Unclas H1/13 30712 . ..-
AS OBSERVED BY ATIS Average Daily Variatims in the Magnetic Field as 6. Pdorring Orpisotion Code Observzd by ATSS 645 I 7. A&(r) 1 8. Pwforming Orynixatien Report No. Thomas L. Skillman i G-7335 9. Porfaminp-. Qlorimir W.m ond Ahsr !IO. WO~LUnit NO. Goddird Space Flight Center ?11. Controct or tront No. Greenbelt, Maryland 2077 1 113. TYw of Rmrt and Period Corerd 2. Spaswing 4mcr badAddmr National Aeronautics and Space Administration 1 Technical Report Washington, D. C. 20546 f 14. Spoasoring Apmcy Code
6. Absh#) Hourly averages of the magnetic field components are determined and analyzed using the measurements of the magnetic field monitor aboard the ATSS. The data covering the time period of September 1969 through September 1971 are sorted and analyzed for various Kp values, gee magnetic latitude of the subsolar point, and local time. Local time variations are harmonically analyzed, and amplitudes and phases are given up to the fourth harmonic.
space sciences, Geophysics, Magnetic fields at synchronous orbit Unclassified-Unlimited at. 13 P. Scurity Clor1if. (of hisreport) 120. kurity Clorrif. (of rhir pow) 21. No. of roes 22. Pric.’
Unclassified 42 $3.00 A CONTENTS
page ABSTRACT ...... 1 IXTRODUCTION ...... 1 MAGNETIC FIELD MEASUREMENTS ...... 2 DATA REDUCTION ...... 3 ANALYSIS ...... 4 DISCUSSION ...... 6 ACKNOWLEDGMENTS ...... 7 REFERENCES ...... 27 SOURCES ...... 27 APPENDIX - MAGNETIC FIELD DATA ...... A-1 AVERAGE DAILY VARlATIONS IN THE MAGNETIC FIELD AS OBSERVED BY ATSS Thomas L. Skillman Goddard Space High t Center
INTRODUCTION Applications Technology Satellite5 (ATS-5). launched on August 12. 1969, was the fifth in a series of satellites conceived and designed by NASA/Goddard Space Flight Center with the program objective of furthering the state-of-the-art in applications technology, placing emphasis on satellif e communications and meteorology. Due to excessive onboard damp ing during an interii7ispinstabilized phase of flight, spin about an unstable axis deteriorated to an anomalously flat spin shortly after the spacecraft was positioned in the synchronous orbit. The spin axis was rotated to the position of the original spacecraft axis by ejecting the apogee motor casing on September 5. but it was spinning in the opposite direction The momentum removal systems were unable to reduce the spacecraft spin. Consequently, all experiments depending on the planned gravity-gradient stabilization became inoperative, and the mission was declared a failure. Two systems capable of operating in the spinning condition were the magnetic field monitor (MFM)and portions of the environmental measurements experiment (EME). The EME was a scientific experiment package consisting of six experiments, four of which have operated continuously since turn-on. Specifics of these experiments are listed in Table i . The MFM was not onboard as a scientific experiment, out was to be used along with three- axis torquing coils as a backup attitude-control system during launch and maneuvering to the on-station position. The magnetometersensor is mounted on the antenna boom approx- imately 1.37 meters (4.5 ft) from the center of the spacecraft. Figure I shows the instru- ment perched midway on the boom at the top of the photograph. It is covered by an alumi- nized Mylar thermal blanket to passively control the temperature range of the sensor. The temperature encountered by the sensor was nominally near 273.15 K (0" C) varying from 268. IS to 278.15 K (25"Cj with the sun's position. However, the temperature dropped when the spacecraft was shadowed by the earth; for instance, during an eclipse of maximum duration (approximately 80 minutes), the temperature dropped to 248.15 K (-25°C) (see Figure 2). Figure 3 is a diagram sljowing the positions of the MFM sensor and electronics. The output of the magnetometer is fed into the EME telemetry systsm (pulse frequency modulation (PFM)) for inclusion on each experimenter's data tapes. The prime output is on the spacecraft telemetry system (pulse code modulation (PCM)) and has been recorded approximately 60 percent of the time since launch. Information about the magnetometer and the telemetry systems may be found in Skillman.'
1 ATS-5 was spinstabilized at 77 rpm about the spacecraft z-axis, which is approximateiy parallel to the earth's rotational axis, and has been on-station at 105"k 1" W longitude since September 1 1, 1969. The inclination of the spacecraft changed with time from its initial value of 2.5" to a value of 0.5" in September 197 1. Changes in the orbit inclination and right ascension of the ascending node alp shown in Figu-s 4 and 5. Figure 6 illustrates tile ATS-5 orbit and spin geometry. it shows the satellite in Ihe synchronous orbit (w = 1 rev124 hoursj at the fixed earth longitude of 105" W. The spacecraft is spinning about the -z body axis and the spin vector is pointing north. The angle 6,defmed as the angle be- tween the -x axis and the plane containing the spin axis and the spacecraft sun vector, is xsed in the description related to the despinning of the PCM data. The coordinate system is that used by G:neral Electric, the subcontractor responsible for attitude determination of the spacecraft. MAGNETIC FIELD MEASUREMENTS
The MFM is a triaxial fluxgate magnetometer with a range of approximately +SO0 y and a sensitivity of 1 y. !'he field is measured along each axis by combining a fine reading within a range of +25 y with a coarse reading indicating the necessary number of steps to be fed into a compensating coil to keep the instrument within the range of the fine scale. There are 32 steps of approximately 33 y for each axis, thereby providing a nominal range of -495 to 525 y. Along each axis of the fluxgats coordinate system the magnetic field component is thus determined from the following formula:
where B = magnetic field along the sensor axis in gammas A = constant gamma field increment for each digital compensating field fN) = digital number telemetered back giving the status of current steps applied to the sensor compensating coils D = constant number of gammas per voit for fluxgate axis over the linear portion of its response curve if= output voltage from the fluxgate (nominally 0.75 to 4.25V) C= voltage (a constant) for zero magnetic field along sensor axis Constants A, D,and C vary for different sensor :xes. A calibration field of 10 y per axis is internally generated once every 12.02 hours for a duration of 5.63 minutes as a means of checking the Tagnetometer sensitivity. The constants used for the ATS-5 magnetometer in Equation 1 are as follows: Ax = 32.804 y Dx 13.49 ylV Cx= 2.49V AY = 32.942 y Dy 13.85 -y/V cy= 2.52v At = 32.775 y Dz = 13.63 -ylV c* = 2.55v
2 For the fine output the frequency responses of the magnetometer (sensor and electronics combined) are: PCM: approximately 100 Hz at 3 dB PFM: approximately 0.1 1 S Hz at 3 dB The data sampling intervals for each axis are: PCM : Fine 2.97 slsample Coarse 95 slsample PFM: fine and coarse 5.12 s/sample
DATA REDUCTION ,'Some general comments should be made about the accuracy of the measurements used in this report. First, the magnetometer was onboard the spacecraft as a monitor, not as an experiment. Sxond, the spacecraft was not magnetically clean; and, as a result, it en- countered I;irge disturbances from both ac and dc fields. The dc fields as measured at the GSFC Magnetic Test Facility were compensated by six auxiliary magnets with the following field modifications at the magnetometer:
Magnetometer coordinate ' Initial perm field Compensated
X 119.7 7 2s 7 Y - 80.8 7 31 r z -164.0 7 109 7
The large field remaining in z was purposely set at f -39 7 to ensure maximum range when onstation in synchronous orbit. Prior to flight. dc offsets resulting from various spacecraft functions being turned on and off were recorded. These corrections, some of which changed after launch, have been used to correct the data. This was accomplished by observing sudden field shifts of the spin axis (2) output on the plotted data and correcting the field value accordingly. Where sudden jumps ir. the dc level were obscived, the command log from the ATS-5 control center was checked to see whether a command had been rent to the spacecraft. If a command had been sent, the resulting shift was compared to the preflight test to see if the observed shift was consist- ent with the test. Typically these corrections vaned from 1 to 20 7. Corrections observed during ground testing for ac fields and later verified in flight were also applied to the data to eliminate the effects of the solar array modulation due to the space- craft spin. These corrections were always less than 10 r.
The data used in the hourly value data set for the spin axis (2) component were supplemented with data from the PFM telemetry system when not available on the PCM telemetry output.
3 The PCM teicmetry output in the spin plane (x, y plane) was despun by a program developed 3y General Electric Valley Forge Space Center. This investigation was performed under :ontract by GE, the spacecraft attitude control subcontractor. who was completely familiar with the spacecraft, specifically with the various sensors onboard. For a report of this study sontract and the details of the despinning technique, see Mueller and Coync2 The despun data were transformed to the DHV components of the magnetic field using the iun sensor mtput and the following assumptions: (a) The AT'S-5 spacecraft is located at synchronous altitude at 105" W longitude and 0" latitude and is stationary in a geocentric reference frame corotating with the earth. (b) The vehicle is spinning about its -z (GE body frame) axis, which is aligned with the earth's spin axis, with no nutation. This DHV system is the same as that used by Coleinan and Cummings3 for the analysis of the ATS-1 magnetic field data and is illustrated in Figure 7. The north (H) Component is obtained directly from the +z magnetometer mt .\urements. The east and outward components (D and V, respectively), are obtained from the x and y components by the despinning technique previously mentioned. It should be noted here that the east component, D, is a force unit and not an angular measure such as declination in the conventional usage of the notation D. Also note that H is the north component and not the total horizontal intensity.
ANALYSIS After the geomagnetic latitude of the subsolar point earn was computed for each hourly value observed, the data were sorted into three categories: e;,,, > 10",-10" < 0' For each magnetic field component and for each (Kp, dim) group, hourly averages (each centered at the half-hour) and standard deviations were computed for each loa1 time hour (see Appendix). To indicate the statistical significance of these averages, the maximum and minimum numbers of houriy data points (used in avera@ng) and the maximum and mini- mum standard deviations are given in Tables 2 through 4 for each (Kp, e;,,, ) group. It should be noted that the number of data points for very disturbed conditions of Kp 2 4 is unavoidably small for some local hours. Fieure 8 presents the daily variations in the magnitude, F, and H,D, and Y components of thc magnetic field at the ATS-5 position. To facilitate comparison of the daily variations for different etrn groups, classification is made first with respect to Kp, and for each Kp group, three curves are drawn for the three 6imgroups. 4 In Figure 9 the same data are presented in a different form; namely, division is made first according to OS,,, , and for each e;,,, group, three curves are prepared for the three Kp groups to show the dependence of the daily variations on magnetic activity. A separate diagram, Figure 1 a, is presented to give the daily variations in the dip angle I, where I is computed from the formula tan I = -V/,,!D6. The inaximum and minimum values of I and the local hours at which these maxima and minima occur are listed in Table 5 together with the ranges of I. Figures 1 1 and 12 contain plots of angle variations determined from hourly average values for tilts ir? the HV and HD planes. Each average daily variation f(r) is then expressed in a Fourier series as 9 Ar) = a,,, cos mt + b,,, sin mt Y m=O where Crn =J- m=0,1,2,... , Tables 6 through 8 give the amplitudes Cm and phases a,,, for F,H, V, and D. Table 9 lists the time of the maximum for the diurnal (24-hr) component of each of these elements. In Figur.: 8 the daily variations for difference O;,groups are presented for each Kp group. The seasonal classification therefore is made using the geometric parameter e;,, ; that is, the geomagnetic latitude of the subsolar point. This classification is more precise and convenient for the study of the distortions of the magnetospheric field due to the solar wind than a classification according to the calendar season. However, the seasonal changes in the daily variations by use of the ordinary season classification are of value in certain types of statistical studies. Figdre 13 contains plots of the average daily variations for the four seasons defined as follows: Sertson 1 D;iy of Year 1 Dates -1 Summer 128 to 218 May 8 to August 6 Fall 219 to 309 August 7 to November 5 Winter 310to 35 November 6 to February 4 5 DISCUSSION The plots in Figures 8 and 9 clearly show the effects of increased magnetic activity on the daiiy variations. The largest variations occur near local midnight because of the diamagnetic effects of increased plasma intensity. The sorting of the data by geomagnetic latitude of the subsolar point emphasizes twc points. First, there is an apparent change in phase in the y (D)and -z (V)directions as shown in Figure 9. Second, there is a significant difference in the <- IO" trace in Figure io when compared with the other two Bin traces in the same plots. This difference IS also evident in the I) and Y plots in Figure 13. The position of ATS5 is '7' to 10" north of the geo- magnetic equator. Therefore, during the winter (dim <-lo"), ATSd is closest to the equatorial current sheet. The existence of this current sheet has been established by the Orbiting Geophysical Observatory-3 and -5 (OGO-3 and -5) magnetic field observations! Figure I3 shows appreciable differences between spring and fall. In Figures 8 to 10 these differences are masked because the geomagnetic latitude of the sun was used for the classi- fication of the data, thereby combining two equinoctial seasons. The presence of the anma1 variation seen in Figure 13 was quite unexpected, because such a variation calls for an cxplanation that goes beyond Lhe geometrical configuration of the current sources relative to the sun'sgeomagnetic latitude. This implies that there is either a true annual variation in the solar-wind conditions or a hysteresis effect in the response of the magneto- sphere to the seasonal variations in the solar wind. To study the apparent phase changes in D (yl and V (-21, the data were subdivided into the calendar seasons. This breakdown resolves the -10" < 6im< 10" in Figure 8 into spring and fall in Figure 13. The difference in these two seasonal traces is most prominent in the V (-2) plots of Figure 13. Figure 14 is a further subdivision of the data for Kp = 0, 1 for each calendar month. Gradual phase changes are apparent in both D and V. There seems to be a reversal in phase in these components near February to March. Correspocding to this phase reversal, a slight, but noticeable, phase shift is observed in H. The data were next compared with ca1cula;ed field values taken from the ATS-5 ephemeris data. The ephemeris data include component field values for the ATSJ position at 10- minute intervals for a "regular" (geomagnetic reference field) and a "distorted" field model. The model for the regular field is determined from the GSFC/65 epoch 1965.0 of Hendricks and Cain' and represents the internal field of the earth. The distorted field takrs into account the additional effects of the solar wind and geomagnetic tail. These calculations are from the Mead-Williams model6 using a 40-7 tail field. Figure 1 S displays the computed values for four days: day 172, 1970; day 264, 1970; day 355, 1970; and day 80, 1971. These days are the equinoxes and solstices and are compared here with the observed hourly averages compiled monthly which include these dates. The observed H trace follows the shape of the Mead Williams model fairly well, but has a more or less conitant higher field value of 5 to 25 7. 6 The D and V plots in Figure 15 show both amplitude and phase differences when compared with either of the calculated fields. These differences between the measured and calculated field value.; are assumed to be due to the equatorial current sheet. It should be noted that the phase changes in the calculated field.. 'or the various days are probably due to changes in the geomagnetic latitude of the satellite because of the orbit inclination. Figure 16 shows the variation of geomagnetic latitude of ATSd with season and local time. The importance of geomagnetic latitude variations on satellite measurements, even when the satellite is in a nominal synchronous equatorial orbit such as the ATS satellites are, is again stressed. In summary, the present study of the daily variations in the magnetic field as observed by ATS-5 suggests a need for an improved magnetospheric field model that takes into account the recent finding of the equatorial current sheet. The existence of the annual change in the daily variation of the magnetic field at the synchronous orbit, as indicated in the spring-fall asymmetry, should be studied further. Cornparism of the present results with the OGO-3 and -5 observations will be made in a separate report. ACKNOWLEDGMENTS The author wishes to thank Dr. M. Sugiura for his assistance and Dr. B. Ledley for his discussions and suggestions. Goddard Space Flight Center National Aeronautics and Sp 2 Administration Greenbelt, Maryland February 21,1973 188-36-5W-51 7 -40 L i -20"OF=- ~~ L.-,u u L- ULI 0 E 16 24 0 8 16 21 0 8 16 24 0 8 16 24HOURS 1969 1970 1971 1972 Figure 2. ATS-5 magnetometer sensor temperature. 9 Figure 4. Orbit inclination. Figure 6. ATS.5 orbit and spin geometry. 10 w u II w u)rI- 1u I X>N -> Z I Id 4 f isV N' I f > r "i/--I -_.. ...I ...- .:i I:'\x + I I GIMMAS h - 0.1 -lor--- 7 AIS-5 IKWULY VALUE (bed tirmj GAMMAS Figure 8. Daily variations in the magnitude F and H, 0, and V ;,rponmts of the magnetic field at ATS-5. 12 Figure 9. Daily varktioac in the magnitude F md H,D, md Y unnpcmeats of the -tic fkld 8t ATs-5. 13 40 K, = 2,3 LOCAL TWP Figure 10. Daily variations in the dip angle I of the magnetic field at A FS5. 14 Figure 11, A'S5 tilt angle 5 as 1 ~mctionof time. LOCAL TIME Figure 12. ATS-5 tilt angle a as a function of time. X=H 2-=A 0 X=H I--A X=H 16 w SVIIWVB 0 SVWWVB v-L)YT -10 L DAV 172 J I-" Pigun 15. Comparisons of ATS magnetic tklds and computed theoretical fltidr. 18 8 7O 2 4 6 8 10 12 14 16 18 20 22 0 2 4 LOCAL TIME Figure 16. ATSS geomagneticlatitude. 19 20 Table 2 Numbers of Samples and Standard Deviation for e:,,, 6; -10' Table 3 Numbers of Samples and Standard Deviation for -10" 21 Table 4 Numbers of Samples and Standard Deviation for e;,,, > 10". rr1 1 1 I Component 1 I Number of Samples Standard Deviation 7 I Kp Maximum Minimum Maximum Minimum H , 99 27 8.46 4.87 0, 1 > , 2Y3 119 33 17.95 6.34 >4 29 6 20.18 4.3 1 V 0, 1 88 24 I 8.10 3.98 ~ 2,3 108 26 10.64 5.12 .4 30 2 12.51- 1 .oo D 0, 1 88 24 4.72 1.55 - , 2Y3 108 27 7.50 1.99 24 30 2 9.28 1 SO Table 5 Maximum and Minimum Values of the Angle of Dip (I). Maximum Minimum Total Range KP (deg) I (deg) Local Time I (deg) Local Time (deg) 6u -10 23.3 19.5 4.8 06.5 16.5 -io 22 Table 6 Values of C, and a, for (9;" < -10' Parameter m Component Kp 0 1 2 3 4 F 0, 1 c,,r 129.6 14.5 0.8 0.8 1.0 am9 deg - 17 -1 -36 85 293 cm97 124.8 21.1 2.5 .8 .3 I 7-13 I 9 -66 1 an! deg - 20 -57 - >4 c,,r 118.8 20.8 4.5 ?.I ! .5 - a,9 deg - 22 49 63 50 -L H 0, 1 c,,r 123.0 16.5 .6 0.5 0.9 a, 9 deg - 33 9 -4 6 75 293 c,,r 117.3 25.2 2.1 .5 .5 am9 deg - * 31 -54 -52 8s >4 cmyr 109.5 27.1 4.5 1.7 .9 am9 deg - 35 28 48 -86 D 0, 1 c,97 15.7 4.6 ."< .4 .3 am9 deg - 23 -83 -80 79 293 c,,r 15.7 5.4 1.5 .7 .3 am9 deg - 18 55 68 -16 >4 c,,r 14.9 6.3 3.1 .7 1.8 am9 deg - 28 64 90 83 -V 0, 1 CmY7 35.3 15.8 .9 .7 .8 am9 deg - -75 -12 5 -5 1 293 cm9 Y 36.3 17.1 1.1 .7 .4 am9 deg - -87 -41 -57 -52 >4 C,,Y 39.1 18.5 1 .o 2.0 1.6 - 86 86 -5 1 -29 23 - Parameter m - Com p o nen I KP I- 0 1 2 3 4 0, 1 Cm,Y 132.5 11.0 1.1 0.6 0.6 IFI - am3 del3 - 14 25 I '70 -- 2-3 Cm,Y 129.1 1.0 3.3 I .3 b del? - 17 4.: -12 -67 9 - - 24 -CmYY 128.3 10.5 8.5 3.9 2.6 - amY deg - 14 66 -12 43 0, 1 cm,r 122.6 17.3 1.9 .7 .5 am9 deg - 13 -14 -80 27 293 cm,r 116.8 23.7 1.8 !O -.2 urn, deg - 21 -90 33 11 24 crn,r 113.1 24.0 7.1 A4 2.4 urn9 del3 -- 20 78 -2 1 51 0, 1 C,,Y 18.1 8.7 2.0 .7 .1 um,deg I - -36 -!l 46 5 233 q+T -1 17.1 8.3 1.3 .8 .s amY deg - -36 57 -5 -48 a44 --crn,r 17.2 9.1 2.7 1.8 1 .o - am3 - -34 -67 -2 6 -V 0, 1 Cm,Y 44.1 14.2 4.8 2.1 .4- urn3 deg I 50 13 -50 -45 293 crn,r 48.2 18.9 4.8 2.5 1.2 urn,deg .- 40 -9 -72 77 -. 24 Cm,Y 52.6 I 25.1 2.5 1.8 !.5 I am9 deg - I 34 -2 78 - 14 24 Table 8 Values of C, and am for Oi,,, > IO". m Compori KP I - 0 1 2 3 4 0, 1 Cm.7 132.1 9.5 1 .o .I .I I - 18 15 78 -59 2.3 Cm.Y 130.4 11.8 3.2 .4 .7 am.deg - 23 25 -8 1 28 cm.7 133.2 10.7 5.4 . 1.3 .5 q---1 I am.deg - 40 33 -18 -3 5 -- 0. 1 Cm.Y 121.2 17.3 0.4 -1 .-3 L 82 -50 48 116.8 22.6 2.3 .6 -4 1); 1); ' -. am. de& 26 72 17 24 Cm,Y 114.5 2S.4 5.3 I .6 .9 am.deg - 27 23 IO 43 I D 0. 1 Cm.Y 18.5 13.2 I .4 .8 .5 a,,, , deg - -54 - 20 -75 -22 2,3 Cm.T 8.2 12.7 3.2 .9 .3 r G~.deg - -53 -36 -75 - 73 24 Cm7Y 18.6 13.7 5.3 2.4 1.1 amt deg - -62 -37 -65 7 0, 1 Cm * 7 45.8 16.6 1.4 .2 .5 a,,,. deg - 17 -27 -29 51 2.3 Cm?Y 50.6 20.9 I .2 .% .7 am7 de&! - 20 -42 59 30 24 Cm9Y 59.5 26.9 , 1.5 1.9 .9 - a,,, , deg - 23 I 63 -58 a2 25 etm deg KP H V D F <-IO 0.1 14.2 7 .O 1.5 13.1 2,3 14.1 6.2 1.2 13.3 x 14.4 5.8 1.8 13.5 - i(Ke;, 26 REFERENCES 1. T. L. Skillman. “ATS-E Magnetic Field Monitor instrumentation.” NASA/GSFC TM X-6385. January 1970. 2. J. J. Mueller and G. W. Coyne. Jr. “Magnetic Data R.e.duction Study Contract.” GE Document 7 1SD4257. September 15, 197 1. 3. Paul J. Coleman. Jr. and W. D. Cummings. “Stormtime Disturbance Fields at ATS-1.” J. Geophys. Res., 76. 1971. pp. 51-62. 4. M. Sugiura. “The Ring Current.” Critical Roblems of Magnetospheric Physics. ed., E. 2. Dyer. National Academy of Sciences, Washington, D. C. :972. pp. 195-210. 5. S. J. Hendricks and J. C. Cain. “Magnetic Field D .a for Trapped-Particle Evaluations.” J. Geophys. Res., 71. 1966. pp. 346.47. 6. D. J. Williams and G. D. Mead. “Nightside Magnetosphere Configuration as Obtained from Trapped Electrons at 1100 Kilometers,” J. Ceophys. Res., 70, 1965. pp. 3017-29. SOURCES W. D. Cummings, P. J. Coleman, Jr., and G. L. Siscoe. “met Day Magnetic Field at ATS-1.” 1. Geophys. Res., 76. 1971. pp. 926-32. W. P. Olson and W. D. Cummings. ‘Y=on1pr?risonof the Predicted and Observed Magnetic Field Lt ATS-1.” J. Geophys. Res., 75, 1970. pp. 7 1 17-2 1. 27 APPENDIX MAGNETIC FIELD DATA A- 1 mINGPAGE BLANK NOT FILMED 2 E a 0 L. n c U C D f 3 U C A-3 C z c c rv-c-on~~eecnoo~~oo~r~~~~~ ...... u c N e n N e F e c - Q 9 m o ii c - I> N v 5 r! v m ...... - - - ...... - - ai Y 2 -L 2 c -Y c n m n E E r n m m m c LT n n E r n c n n n n G n 3o-wn.b...... ec 000-w no+acaoo-~n ------ri%t,hh U -- 0 n C 0 c< b a c i( 3 0 c b .- -I 5: Y u: w 3 A-6 f a 0 Y- c ma...... n c. n nn e. IJ- IP. e n c e n IP e e E a VI u -1 E ~O-NO+DQC~D~-N*.CCCB~O-N~ -*I - L -- - - - I-4 N <* h U a P a a P j! A-7 c - m - c o e Y N n c* c - -r onc CIC E m h Q e ...... w Y, Q o o o c - n (Y e o c N - (. Q tu m N n e 0 Q C J C h c 0 4 0 e l C u c C. PIN h h e Z, PC ,-- J C f v ,o ,o .. 0 #NO a 9CQc 9s- 0 s a E U II Y 5 -I t -canmans, mod srr ...... N c* do-~nen z'di NN4 --N U A QNP~~n-v-oao ...-neoecQne ...... N e e e a r y: e ri ly 475 cmm... NO*N-- -Nr) NmN A-8 a C 3 a 0 N E 9 ~~~I~-cN~QQNNQ~QQN~~~~~~- >e~ooc~ocrtenen~eo-~n~~c4 W...... a e u c m Y, c c c c c o .o c c I. c c Y) ro u, 0 Y) c sc 0 A-9 w I 3 U r 3 a p: z c m -e *(e 0 Qcn 0 Le -Pa- mc JNIQ en00 00 r~+~or~~b40-enncmn~~~~~en U...... GPCC~n< n~ic~~firnv~~cut~m-~ us a f z A-1 1 f c, t F 1, C 3 Y P n n-12 E 2 c c V a A-13 a a c c< v) U 3 0 i ul k k u A-14