NASA TECHNICAL MEMORANDUM

03 ";" x

N.4S.4 TM X-53186

DECEMBER 22, 1964

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._ RADIOSONDE AUTOMATIC DATA PROCESSING SYSTEM

by ROBERT E. TURNER 4ND RICHARD A. JENDREK Aero-Astmdynamics Laboratory

NASA

George C. Mdrshull = L S'uce Flight Center,

Hantsuille, Aldbdmu

TECHNICAL MENORANDUM X-53186

RADIOSONDE AUTOMATIC DATA PROCESSING SYSTEM

Robert E. Turner and Richard A. Jendrek:k

George C. Marsha l l Space F l i g h t Center

H u n t s v i l l e , Alabama

ABSTRACT

This r e p o r t d e s c r i b e s an, o p e r a t i o n a l Automatic Radiosonde Data Pro- c e s s i n g System developed f o r use with the AN/GMD-2 Rawin S e t . of r e l i a b l y i d e n t i f y i n g t h e time-shared tempera ture , humidi ty and r e f e r e n c e f requency in fo rma t ion from a modified AN/AMQ-9 Radiosonde is d e s c r i b e d .

The method

Th i s r e p o r t shows t h a t automatic r e d u c t i o n o f rad iosonde d a t a by t h e d e s c r i b e d method posses ses o p e r a t i o n a l c a p a b i l i t i e s as demonstrated by more than 300 ba l loon-borne me teo ro log ica l soundings from September , 1963 t o November 1964.

*Richard A. J endrek is a s s o c i a t e d wi th t h e Bendix Corpora t ion , working under c o n t r a c t No. NAS8-5246.

NASA - GEORGE C, MARSWLL SPACE FLIGHT CENTER

NASA - GEORGE C. MARSHALL SPACE FLIGHT CENTER

~~ ~

Technical M e m o r a n d u m X-53186 ~~~~ ~

D e c e m b e r 22, 1964

RADIOSONDE AUTOMATIC DATA PROCESSING SYSTEM

BY

R o b e r t E. Turner a n d R i c h a r d A. Jendrek

ATMOSPHERIC MEASURING GROUP AERO-ASTROPHYSICS OFFICE

AERO-ASTRODYNAMICS LABORATORY

TABLE OF CONTENTS

Page

I . I ~ R O D U C T I O N ............................................... 1

I1 . DESCRIPTION OF SYSTEM ...................................... A . Data Processor ......................................... B . Radiosonde Changes ..................................... C . Rawin S e t Modi f ica t ions ................................

111 . THEORY OF OPERATION ........................................ A . Decomuta t ion Method ................................... B . Meteoro log ica l Data Handling ........................... C . Tracking Data Handling .................................

I V . RAWIN SET OPERATION ........................................ A . Controls and I n d i c a t o r s ................................ B . Impor tan t Aspects of Rawin S e t Performance ............. C . Raw Data F a l l b a c k C a p a b i l i t i e s .........................

V. TEST PROGRAM ............................................... 9

V I . CONCLUSIONS ................................................ 10

iii

L I S T OF ILLUSTRATIONS

T i t l e

Radiosonde Automa t i c Data P rocesso r w i t h o u t S l a n t '

Range P r i n t e r ....................................... ADP System I n s t a l l a t i o n ............................. Radiosonde Comuta t o r f o r ADP System ................ Typical Card Showing Output Format .................. Meteorological S i g n a l P a t t e r n ....................... ADP System Block Diagram ............................ MSFC Atmospheric Research F a c i l i t y .................. Sample of Atmospheric Data (Temperature v e r s u s A l t i t u d e ) ........................................... Sample of Wind Data (Wind Speed and D i r e c t i o n v e r s u s A l t i t u d e ) ...........................................

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TECHNICAL MEMORANDUM X-53186

RADIOSONDE AUTOMATIC DATA PROCESSING SYSTEM

SUMMARY

Th.is r e p o r t d e s c r i b e s a n o p e r a t i o n a l Automatic Radiosonde Data Pro- c e s s i n g System developed f o r u se wi th t h e AN/GMD-2 Rawin S e t . of r e l i a b l y i d e n t i f y i n g t h e time-shared tempera ture , humidi ty and r e f e r - ence f requency in fo rma t ion from a modified AN/AMQ-9 Radiosonde is desc r ibed .

The method

The r e p o r t shows t h a t au tomat ic r e d u c t i o n of r ad iosonde d a t a by t h e d e s c r i b e d method posses ses o p e r a t i o n a l c a p a b i l i t i e s a s demonstrated by more than 300 ba l loon-borne me teo ro log ica l soundings from September, 1963 t o November 1964.

I. INTRODUCTION

Rawin S e t AN/GMD-l, developed by t h e U. S. Army S i g n a l Corps, has been i n o p e r a t i o n a l f i e l d use by va r ious m e t e o r o l o g i c a l a c t i v i t i e s s i n c e 1950, This equipment has proved very r e l i a b l e i n t r a c k i n g t h e AN/AMT-4 and o t h e r 1680 mc rad iosondes which use p r e s s u r e t r a n s d u c e r s and provides a n a c c u r a t e means f o r d i r e c t a l t i t u d e computation.

The Control Recorder u n i t s of b o t h the AN/(;MD-l and t h e AN/GMD-2 Rawin S e t s p rov ide manual remote c o n t r o l of t h e t r a c k i n g an tenna and tun ing of t h e 1680 m c r e c e i v e r as we l l a s power d i s t r i b u t i o n . t r o l Recorders w i l l p e r i o d i c a l l y p r i n t t h e numerical v a l u e s of t h e az imuth and e l e v a t i o n a n g l e s and e l apsed time from r e l e a s e . Recorder w i l l p r i n t t h e s l a n t range and computed a l t i t u d e v a l u e s s imul- t aneous ly w i t h the time and t r ack ing a n g l e s . employ t h e AN/TMQ-5 Radiosonde Recorder t o trace t h e t empera tu re , humidi ty , and r e f e r e n c e s i g n a l s w i t h a pen on a cont inuous s t r i p c h a r t .

Both Con-

The AN/GMD-2 Cont ro l

Both Rawin S e t s normal ly

The s e p a r a t e t r a c k i n g and me teo ro log ica l d a t a t h u s r eco rded must b e manual ly t r a n s f e r r e d from t h e c h a r t s po in t -by -po in t and c o r r e l a t e d w i t h e l a p s e d time f o r computing and developing t h e d e s i r e d upper a i r p r o f i l e s . I n a n e f f o r t t o e l i m i n a t e t h e requi rement f o r a n o p e r a t o r t o perform t h i s t a s k , a number of schemes f o r au tomat ic and semi-automat ic p rocess ing of r ad iosonde d a t a have been dev i sed w i t h va ry ing degrees of s u c c e s s .

The system d e s c r i b e d h e r e i n was s u p p l i e d by t h e Bendix F r i e z I n s t r u - ment D iv i s ion f o r t h e N a t i o n a l Aeronaut ics and Space A d m i n i s t r a t i o n ' s Atmospheric Research F a c i l i t y a t Marsha l l Space F l i g h t Center , H u n t s v i l l e , Alabama. The complete sys tem was des igned and c o n s t r u c t e d w i t h i n s i x months and was d e l i v e r e d t o MSFC f o r i n s t a l l a t i o n i n September 1963.

11. DESCRIPTION O F SYSTEM

A. Data Processor

The Bendix F r i e z Model 1146450 Radiosonde Automatic Data Processor is shown i n F igure 1. A l l ADP component c h a s s i s a re con- s t r u c t e d f o r i n s t a l l a t i o n i n s t a n d a r d 19- inch r e l a y r a c k s . The t o t a l mounting h e i g h t r e q u i r e d is 95 inches . To minimize eng inee r ing d e s i g n e f f o r t a number of f u n c t i o n a l u n i t s used i n t h e sys tem were procured a s "o f f - the - she l f " i tems w i t h only minor m o d i f i c a t i o n s r e q u i r e d i n some cases t o provide sys tem i n t e r f a c e . The remaining u n i t s which i n c l u d e t h e t r ack ing d a t a D i g i t i z e r , t h e Conver te r -Detec tor , and t h e Cont ro l - Decommutator were wholly des igned and f a b r i c a t e d a t Bendix F r i e z . The l a t t e r two u n i t s c o n t a i n t h e l o g i c and c o n t r o l c i r c u i t s e s s e n t i a l f o r automation of t h e me teo ro log ica l d a t a t r a n s m i t t e d by t h e rad iosonde . The Data Processor a u t o m a t i c a l l y commands an I B M 526 p r i n t i n g summary punch t o punch ca rds a t 5- o r 10-second i n t e r v a l s a s d e s i r e d . A t y p i c a l card is shown i n F igure 4 .

B. Radiosonde Changes

A s p e c i a l commutator was des igned f o r i n s t a l l a t i o n i n t h e t ransponder sondes (AN/AMQ-9) used w i t h t h i s system. The new commutator, shown i n F igure 3 , d i f f e r s from t h e one i t r e p l a c e s p r i n c i p a l l y by t h e nominal 1 1 2 second r e f e r e n c e segments preceding each tempera ture and humidi ty segment. These s h o r t r e f e r e n c e segments a r e used t o i d e n t i f y a change from one senso r t o the nex t i n the rad iosonde measuring c i r c u i t . A s a consequence of adding t h e 112 second i d e n t i f i e r s , i t was necessa ry t o reduce the nominal d u r a t i o n of t h e remaining tempera ture , humidi ty , and r e f e r e n c e segments from 4.5 seconds t o 3.9 seconds.

The s l a n t range is measured and punched o u t i n me te r s , r e q u i r - i ng a change i n t h e r ang ing modulat ion f requency from 81,940 c y c l e s pe r second t o 74,950 c y c l e s pe r second. The tuned a m p l i f i e r i n t h e AN/AMQ-9 rad iosonde w a s r e t u r n e d t o t h e lower f requency a f t e r t h e s p e c i a l comnu- t a tor . was i n s t a l l e d .

2

C. Rawin S e t Modi f i ca t ions

The d a t a p rocesso r was designed t o o p e r a t e w i t h e i t h e r of two AN/GMD-lB Rawin s e t s upgraded t o c o n t a i n the ranging measurement c a p a b i l - i t y of t h e AN/GMD-2. two p a i r s of t r a n s m i t t e r and comparator t o measure i n meters and i n s t a l l - i ng them on the two p e d e s t a l s . A h i g h p a s s f i l t e r and the t r a n s m i t t i n g an tenna were i n s t a l l e d on the sp inne r pylon, and t h e p e d e s t a l swing l i n k s were turned t o t h e 0 - 2 p o s i t i o n . The GMD-1 Control Recorders were modified t o be compatible wi th the conver ted p e d e s t a l s . This r e q u i r e d a p l u s and minus 27 v o l t s d i r e c t c u r r e n t supp ly f o r r e c e i v i n g t u n i n g , a new Receiver Tune switch, and some rewi r ing . The p r i n t o u t , t h e v i s u a l i n d i c a t i o n , and the monitoring of s l a n t range d a t a a r e handled by t h e d a t a p rocesso r .

The ranging m o d i f i c a t i o n c o n s i s t e d of reworking

111. THEORY OF OPERATION

A. Decormutation Method

1. Commutator T rack ing

The approach t o a u t o m a t i c a l l y r ecogn iz ing and keeping i n s t e p w i t h t h e a l t e r n a t i o n s between t empera tu re , humidi ty and r e f e r e n c e f requency from a n AN/AMQ-9 rad iosonde w a s chosen a s a r e s u l t of assuming t h a t s i g n a l f a d i n g c o n d i t i o n s would e x i s t du r ing a t l e a s t p a r t of t h e rad iosonde f l i g h t . The s t a n d a r d AN/AMQ-9 Radiosonde S e t t r a n s m i t s a r e p e a t i n g pa t t e r n of :

r e f e r e n c e 4.5 seconds

space .5 seconds

temp e r a t u r e 4.5 seconds

space .5 seconds

humidity 4.5 seconds

space .5 seconds

temp e r a t u r e 4 .5 seconds

space .5 seconds .

3

The r e f e r e n c e frequency is 190 Ir. 20 p u l s e s p e r second and t h e temperature and humidity f r e q u e n c i e s a r e always below the a c t u a l r e f e r e n c e frequency by a t l e a s t 15 p u l s e s p e r second. No t i ce t h a t 1 1 frequency" and "pu l se per second" a r e i n t e r c h a n g e a b l e . Recogn i t ion of t h e r e f e r e n c e frequency is s imply f i n d i n g t h e h i g h e s t f requency of t h e t h r e e . Upon d e t e c t i n g t h e r e f e r e n c e frequency, a d e l a y of 5 , 10, and 15 seconds w i l l l o c a t e the t empera tu re , humid i ty , and the tempera- t u r e frequency t r ansmiss ion p e r i o d s , r e s p e c t i v e l y . However, i f a s i g n a l dropout occurs du r ing the r e f e r e n c e frequency t r a n s m i s s i o n , a 20-second b lock of da t a is l o s t . A method of de t e rmin ing when a change i s being made from one frequency t o t h e n e x t was t h e r e f o r e adopted.

F i r s t , t h i s i d e n t i f i c a t i o n could n o t be t h e normal 0.5 second space (of z e r o f r equency) between d a t a f r e q u e n c i e s s i n c e a s i g n a l dropout would produce z e r o frequency. Second, a c i r c u i t t o d e t e c t a change i n frequency could n o t be used s i n c e t h e temperature and humidi ty f r e q u e n c i e s a r e o f t e n equa l a t some time d u r i n g t h e f l i g h t . This method i s f u r t h e r plagued by atmospheric n o i s e and s i g n a l d ropou t s which would look l i k e a change i n f requency. The commutator i n t h e r ad iosonde was t h e r e f o r e r ep laced w i t h a new commutator having 0.65-second r e f e r e n c e i d e n t i f i e r s between t h e v a r i o u s d a t a f r e q u e n c i e s . I n c a s e a s i g n a l drop- o u t occurs during a r e f e r e n c e i d e n t i f i e r , a n " a u x i l i a r y advance" c i r c u i t i n t he d a t a p rocesso r w i l l advance t h e decommutator one s t e p . It w i l l no t command a measurement of d a t a s i n c e the p rev ious d a t a a r e probably c l o s e r t o the p rope r v a l u e than a d a t a t r a n s m i s s i o n d i s t u r b e d by a p a r t i a l s i g n a l dropout .

The new commutator p a t t e r n is l i s t e d i n Table 1 below.

TABLE 1. COMMUTATOR PATTERN

Transmitted Data Transmission Dura t i o n

Reference (190 pps) 3.9 s e c

Tempera t u r e 3.9 s e c

Reference I d e n t i f i e r 0.65 s e c

Humid i t y 3.9 s e c

Reference I d e n t i f i e r 0.65 s e c

Tempera t u r e 3.9 s e c

Reference I d e n t i f i e r 0.65 s e c

Humid i t y 3.9 s e c

Reference I d e n t i f i e r 0.65 s e c

Temp e ra t u r e 3.9 s e c

NOTE: Each d a t a t r a n s m i s s i o n l i s t e d i n Table 1 i s s e p a r a t e d by approximately

4 a 0.4-second space .

2. Recogni t ion of Reference Frequency

The pr imary d i f f i c u l t y i n r ecogn iz ing t h e r e f e r e n c e f r e - quency is t h e sp read of 40 pu l ses p e r second al lowed by t h e s p e c i f i c a - t i o n and t h e f a c t t h a t z e r o humidity can produce a p u l s e r a t e j u s t 15 p u l s e s pe r second below t h e a c t u a l r e f e r e n c e frequency. To a t t e m p t t o r ecogn ize r e f e r e n c e a s any frequency above 170 p u l s e s p e r second would e r roneous ly d e t e c t a z e r o pe rcen t humidi ty f requency (175 pps) of a rad iosonde having a r e f e r e n c e frequency of 190 p u l s e s p e r second. To e l i m i n a t e t h i s d i f f i c u l t y , t h e automa t i c d a t a p rocesso r s t o r e s and updates t h e r e f e r e n c e f requency cont inuous ly du r ing t h e f l i g h t . The r e f e r e n c e f requency can then be a u t o m a t i c a l l y d e t e c t e d as t h a t f r e - quency w i t h i n 10 cyc le s pe r second o f t he s t o r e d r e f e r e n c e . This scheme w i l l be workable f o r a l l normal s h i f t s i n the rad iosonde b lock ing o s c i l - l a t o r .

B. N e t e o r o l o g i c a l Data Handling

1. Method of Measurement

The measurement of the tempera ture and humidi ty d a t a is made i n t h e v o l t a g e rea lm w i t h 0.905 v o l t s cor responding t o 190 c y c l e s p e r second. A t y p i c a l me teo ro log ica l s i g n a l p l o t t e d w i t h t ime a s the h o r i z o n t a l a x i s is shown i n Figure 4. The l i n e a r convers ion t o v o l t a g e is accomplished i n the Converter-Detector u n i t . R e f e r r i n g t o the b lock d iagram i n F igu re 5, t h e ou tpu t of t h e f requency t o D C v o l t a g e c o n v e r t e r is connected t o t h e " s i g n a l loss d e t e c t o r , " t h e " r e f e r e n c e d e t e c t o r , " and t h e A t o D Converter . The A t o D Converter is a d i g i t a l vo l tme te r - r a t i o m e t e r w i t h f r o n t pane l decimal d i s p l a y . This u n i t measures t h e r e f e r e n c e f requency ( v o l t a g e ) , the tempera ture r a t i o , and t h e humidi ty r a t i o . The " s i g n a l l o s s de t ec to r " w i l l a c t u a t e i f t he f requency f a l l s below 10 cps (0.047 VDC) f o r more than one h a l f second. The ' ' r e f e r e n c e d e t e c t o r " w i l l a c t u a t e i f t h e incoming f requency is w i t h i n 10 cps of t h e s t o r e d r e f e r e n c e frequency. The measurement and s t o r a g e of meteoro- l o g i c a l d a t a a r e l i nked w i t h t h e decommutation method a s desc r ibed below.

2. Decommuta t ion Logic

The t r a c k i n g o f t h e rad iosonde commutator is accomplished Each t ime t h e " r e f e r e n c e d e t e c t o r " is a c t u a t e d , by a s t e p p i n g swi tch .

t h e s t e p p i n g swi t ch is advanced. The s t e p p i n g s w i t c h "home" p o s i t i o n corresponds t o the r e f e r e n c e segment of t he commutator w i t h the remain- ing f i v e p o s i t i o n s correspond ing t o t h e tempera ture and humidi ty segments. The s t e p p i n g s w i t c h t h e r e f o r e keeps i n synchronism w i t h t h e rad iosonde commutator. When t h e " r e f e r e n c e d e t e c t o r " is a c t u a t e d longer than 1.5 second (as i t is du r ing t h e 3 . 9 second r e f e r e n c e frequency t r a n s - mis s ion ) t h e s t e p p i n g s w i t c h w i l l "home" u n l e s s i t is a l r e a d y i n t h e

5

home'' p o s i t i o n . A word d e s c r i p t i o n of t he sequence of e v e n t s , s t a r t i n g I t

w i t h the r e f e r e n c e f requency , w i l l show t h e s i g n a l f low through t h e s i m p l i f i e d block diagram of F igure 5. The r e f e r e n c e d e t e c t o r a c t u a t e s f o r 3 . 9 seconds and immediately advances t h e s t e p p i n g s w i t c h t o "home" from the l a s t t empera ture p o s i t i o n . A f t e r 1.5 seconds , t h e "home d e t e c t o r " gene ra t e s a home command which w i l l r e e s t a b l i s h synchronism i f t h e s t epp ing swi t ch had f a l l e n o u t of s t e p . A f t e r 2.2 seconds t o t a l d e l a y , a measure command is s e n t t o the A t o D Converter . The mode command of the A t o D Converter is connected through the s t e p p i n g s w i t c h t o the VOLTS mode. The DC i n p u t ( r e f e r e n c e f requency) is measured; the decimal ou tpu t is conver ted t o b i n a r y coded decimal ( B O ) , and appea r s a t t h e BO-to-Analog Converter i n p u t . Within 0.33 second a f t e r t h e A t o D Converter r e c e i v e s i ts measure command, i t g e n e r a t e s a n end-of-measure command which goes through t h e " s i g n a l l o s s d e t e c t o r , " t h e s t e p p i n g swi t ch , t h e " r e fe rence q u a l i t y " c i r c u i t , and the " r e f e r - ence de t ec to r . " The command then causes t h e BO-to-Analog Converter t o s t o r e t h e da t a appear ing a t i t s i n p u t . The " r e f e r e n c e q u a l i t y " c i r c u i t w i l l i n h i b i t s t o r a g e of t h e r e f e r e n c e frequency i f i t is more than 5 cps below t h e p r e v i o u s l y s t o r e d r e f e r e n c e . This guards a g a i n s t s t o r i n g t h e r e f e r e n c e frequency du r ing even a s l i g h t s i g n a l dropout .

F i g u r e 5 shows t h a t t h e r e is no r e f e r e n c e i d e n t i f i e r preceding o r fo l lowing the r e f e r e n c e da ta t r ansmiss ion . The s t e p p i n g swi t ch advances t o t h e f i r s t t empera ture p o s i t i o n a f t e r 3.2 seconds t o t a l de l ay (by means of a c i r c u i t n o t shown on t h e s i m p l i f i e d b lock diagram). A t 2.2 seconds l a t e r than t h e advance of t h e s t e p p i n g s w i t c h , a measure command is s e n t t o t h e A t o D Converter t o measure t h e incoming tempera- t u r e frequency ( v o l t a g e ) . Now t h e A t o D Converter mode command i s swi tched t o " r a t i o " t o measure t h e D C i n p u t a s a r a t i o of t h e r e f e r e n c e v o l t a g e from t h e B O t o ana log conve r t e r . Wi th in 0.33 second a f t e r t he A t o D Converter r e c e i v e s i t s measure command i t g e n e r a t e s a n end of measure command which goes through the " s i g n a l l o s s d e t e c t o r , " and t h e s t e p p i n g swi tch t o t h e Temperature and Humidity T r a n s l a t o r S torage . The command causes the o u t p u t of t he A t o D Converter t o be s t o r e d i n t h e temperature s e c t i o n of t h e Temperature and Humidity T r a n s l a t o r S torage .

The s t epp ing s w i t c h is advanced t o the n e x t , o r humidi ty , p o s i t i o n when the f i r s t r e f e r e n c e i d e n t i f i e r shown i n F igu re 5 a c t u a t e s t h e

r e f e r e n c e de tec tor . ' ' A t 2.2 seconds a f t e r t h e s t e p p i n g s w i t c h is advanced a measure command is s e n t t o t h e A t o D Converter . This time the s t o r e command appears on the ' ' s t o r e H" l i n e of t h e Temperature and Humidity T r a n s l a t o r S to rage u n i t . The s t e p p i n g s w i t c h is advanced each t i m e a r e fe rence i d e n t i f i e r is r ece ived u n t i l t h e long r e f e r e n c e frequency is r ece ived when the e n t i r e sequence desc r ibed above is r epea ted .

II

6

I n case one r e fe rence i d e n t i f i e r i s n o t r ece ived due t o a s i g n a l d ropcu t t h e Control-Decommutator con ta ins an “ a u x i l i a r y advance“ c i r c u i t which w i l l advance t h e s t epp ing swi t ch . N o measure command w i l l be gene ra t ed s i n c e t h e “ re fe rence d e t e c t o r ” w i l l n o t have a c t u a t e d . Synchron iza t ion of the s t e p p i n g swi t ch w i t h t h e rad iosonde commutator is main ta ined , and t h e temperature o r humidi ty informat ion punched o u t on the IBM ca rd is the previous ly s t o r e d d a t a .

C. Tracking Data Handl ing

The azimuth, e l e v a t i o n , and s l a n t range da ta from t h e p e d e s t a l a r e i n t h e form of synchro-s igna ls . By means of a s e l e c t o r swi t ch on t h e Cont ro l Decommutator f r o n t panel , t h e opera t o r swi t ches t o t h e d e s i r e d p e d e s t a l and c o n t r o l r eco rde r . Reed r e l a y s w i t h i n t h e GMD J u n c t i o n box connect t h e Data Processor t o t h e synchro - s igna l s . I n t h e D i g i t i z e r , t h e synchro s i g n a l s p o s i t i o n d i g i t a l encoders and f r o n t pane l i n d i c a t o r s by means of servo-motor d r ives . The d i g i t a l ou tpu t s a r e s t o r e d i n t h e i r r e s p e c t i v e T r a n s l a t o r S to rage u n i t s on command from t h e Timer. Azimuth, e l e v a t i o n , and s l a n t range da ta a r e s t o r e d s imul t aneous ly t o be punched o u t on the card i d e n t i f i e d w i t h t h e proper e l apsed t i m e .

I V . R A W I N SET OPERATION

A. Cont ro ls and I n d i c a t o r s

The C-577 Control Recorder c o n t a i n s a l l the c o n t r o l and moni- t o r i n g f u n c t i o n s r e q u i r e d f o r the Rawin S e t except f o r t h e i n d i c a t i o n of ranging s i g n a l s t r e n g t h and a s l a n t range p r i n t o u t . The range moni tor ing m e t e r s w e r e t h e r e f o r e mounted on t h e Control-Decommutator f r o n t pane l and the s l a n t range p r i n t o u t is provided by a d i g i t a l p r i n t e r ( u n i t 14 i n F igure 6 ) .

B. Impor tan t Aspects of Rawin S e t Performance

The pr imary d i f f e r e n c e between o p e r a t i n g a Rawin S e t a s a GMD-1 and a GMD-2 is t h a t , f o r good r e s u l t s i n t h e GMD-2 mode, a l l p a r t s of t h e Rawin S e t must b e o p e r a t i n g a t o r v e r y nea r peak performance. GMD-1 made w i t h an AN/AMT-4 radiosonde r e q u i r e s o n l y t h e t r a c k i n g and r e c e p t i o n of a 1680 megacycle s i g n a l w i t h a n ampl i tude modulated meteoro- l o g i c a l pu l se . The GMD-2 mode with a n AN/AMQ-9 rad iosonde is more com- p l ex . The r ece ived s i g n a l is frequency-modulated w i t h t h e me teo ro log ica l p u l s e and a 75 kc s i n e wave ranging s i g n a l . I n a d d i t i o n , i n t h e GMD-2 mode, a 403 m c s i g n a l w i t h 75 kc r ang ing modulat ion is t r a n s m i t t e d t o t h e rad iosonde .

The

7

, 1. Receiver Ad jus tments

The frequency modulated s i g n a l from t h e r ad iosonde has a f requency d e v i a t i o n which is n e a r l y equa l t o t h e 600 kc minimum d i s c r i m i - na to r bandwidth. It is t h e r e f o r e impor tan t t o m a i n t a i n a c c u r a t e au tomat i c fr'equency con t ro l - more s o than w i t h t h e AM s i g n a l from a n AN/AMT-4. The I F s t r i p s were a l i g n e d a t Bendix F r i e z w i t h a sweep g e n e r a t o r and an o s c i l l o s c o p e t o ensu re proper d i s c r i m i n a t o r a l ignment . A f t e r t h e r e c e i v e r is a l igned w i t h a p r o p e r l y tuned I F s t r i p , a p a r t i a l l o s s of the incoming 1680 mc s i g n a l w i l l n o t cause t h e r e c e i v e r t un ing t o d r i f t . The ranging and me teo ro log ica l s i g n a l s a r e then smooth and und i s tu rbed dur ing p a r t i a l s i g n a l l o s s .

2. Antenna Control Performance

Tracking accu racy and freedom from antenna hun t ing a l s o improve t h e a b i l i t y t o o b t a i n c l e a n me teo ro log ica l and r ang ing d a t a . When t h e rece ived s i g n a l s t r e n g t h v a r i e s because of t h e swinging of t h e rad iosonde , the antenna should n o t change p o s i t i o n o r t h e me teo ro log ica l and r ang ing data w i l l be d i s t u r b e d . ' Carefu l phasing and Antenna Cont ro l trimming ensure p o s i t i v e and smooth t r a c k i n g of t h e AN/AMQ-9 rad iosonde .

The t h y r a t r o n s i n t h e Antenna Cont ro l u n i t s were r ep laced w i t h s o l i d s t a t e SCR Switching U n i t s , F r i e z P a r t No. 1142256. These u n i t s e l i m i n a t e t h e need t o be r e p l a c i n g t h y r a t r o n s and then r e a d j u s t i n g the Antenna Control a f t e r i n s t a l l i n g new t h y r a t r o n s . The g r e a t l y lengthened MTBF (mean time between f a i l u r e s ) of t h e Antenna Control Uni t i n c r e a s e s the r e l i a b i l i t y of t h e sounding o p e r a t i o n .

C. Raw Data F a l l b a c k C a p a b i l i t i e s

Complete backup d a t a a r e a v a i l a b l e f o r :

1. Checking t h e accu racy of t h e Automatic Data Processor punched card o u t p u t e i t h e r du r ing a sounding o r a t any d e s i r e d t ime.

2 . Manual d a t a handl ing i n case of a ma l func t ion a t a c r i t i c a l t ime.

The ADP system is designed LO g i v e t h e o p e r a t o r t h e a b i l i t y t o observe t h e output i n p r i n t e d form Jn t h e IBM c a r d s , t o observe the meteoro logica l d a t a on the A t o D ( ,onver te r , and t o observe t h e azimuth, e l e v a t i o n and s l a n t range d a t a . Tile p r i n t e d card can be compared w i t h AN/TMQ-5 record t o ensure t h a t th<J me teo ro log ica l d a t a a r e be ing pro- cessed proper ly . In t h e even t t h a t t h e I B M 526 p r i n t i n g summary punch would hang up due t o a damaged card o r some o t h e r r e a s o n , t he raw da ta

8

w i l l be a v a i l a b l e from t h r e e paper r e c o r d s . The azimuth and e l e v a t i o n a n g l e s a r e p r i n t e d (wi th t i m e ) by the C-577 Cont ro l Recorder. The s l a n t r ange and e l apsed t ime a r e p r i n t e d by t h e A u x i l i a r y S l a n t Range P r i n t e r , and t h e me teo ro log ica l d a t a a r e recorded by t h e AN/TMQ-5 Me teo ro log ica l Recorder.

V. TEST PROGRAM

The ADP sys tem was sh ipped from Bendix F r i e z t o MSFC e a r l y i n Septemb.er 1963, f o r i n s t a l l a t i o n a t t h e MSFC Atmospheric Research F a c i l i t y . A c r i t e r i o n f o r acceptance of t h e sys tem by NASA was t h e completion of t e n p e r f e c t radiosonde f l i g h t s . A f u r t h e r requi rement was t h e launching of b o t h t h e AN/AMQ-9 rad iosonde and t h e AN/AMT-4 r ad iosonde on t h e same b a l l o o n t o c o r r e l a t e t h e atmosphere d a t a r ece ived s imul t aneous ly from b o t h systems. The AN/AMT-4 was t r acked w i t h t h e 0 - 1 B Rawin S e t i n t h e normal manual mode and t h e AN/AMQ-9 was t r acked w i t h t h e modi f ied AN/GMD-lB Rawin Se t i n t h e au tomat i c mode.

The i n s t a l l a t i o n and p re l imina ry f l i g h t t e s t s w e r e completed by September 24, and t h e f i r s t o f f i c i a l accep tance f l i g h t t e s t s w e r e s t a r t e d . During October the ten acceptance f l i g h t s were completed, and t h e sys tem was p laced i n f u l l o p e r a t i o n .

During t h e s e t e s t s , the raw atmospheric parameters w e r e p l o t t e d from t h e AN/AMT-4 and AN/AMQ-9 Radiosondes. N o manual o r computer r e d u c t i o n was accepted f o r q u a l i f i c a t i o n .

The AN/AMT-4 raw d a t a c o n s i s t i n g of tempera ture and humidi ty o r d i n a t e s and e l e v a t i o n and azimuth a n g l e s were p l o t t e d every 30 seconds.

The AN/AMQ-9 raw d a t a c o n s i s t i n g of tempera ture and humidi ty r a t i o

These d a t a were compared w i t h those p l o t t e d from da ta punched e l e v a t i o n , azimuth a n g l e s , and s l a n t range w e r e p l o t t e d eve ry f i v e seconds . on summary punch c a r d s .

A f t e r comparing t h e AN/AMT-4 and AN/AMQ-9 Radiosonde raw d a t a w i t h t h a t of the ADP System, a l l d a t a e r r o r s were found w i t h i n t h e accu racy of t h e s e r ad iosonde ' s s e n s o r s .

S ince two modi f ied AN/GMD-lB S e t s were used on each f l i g h t , t h e ADP System was swi tched from one s e t t o t h e o t h e r du r ing each f l i g h t . The on ly change i n t h e da t a w a s i n s l a n t r ange , w i t h a n e r r o r of l e s s than 10 me te r s per swi t ch ing .

9

One important a s p e c t of GMD-2 performance was d i scove red from com- pu t ing a f i n a l d i f f e r e n c e of t h e d a t a on a n IBM computer. During the p re l imina ry tests, t h e s l a n t range da ta would be changing a t t h e r a t e o f , s a y , 30 me te r s p e r f i v e seconds e x c e p t f o r occas ions where t h e f i r s t d i f f e r e n c e would read 170, then -110. This s l a n t range runou t was found to be due p a r t i a l l y t o s i g n a l fad ing . The comparator is des igned t o f u n c t i o n w i t h a 75 k c r ang ing s i g n a l i n p u t of 0.015 t o 0.150 v o l t s RMS. Below 0.015 v o l t s RMS i n p u t , t h e comparator g e a r t r a i n can cont inue running . A t r a n s i s t o r i z e d c i r c u i t was t h e r e f o r e added which w i l l s t o p t h e servo-motor when t h e i n p u t t o t h e comparator f a l l s below a c e r t a i n l e v e l . The ad jus tment w a s made once and has n o t r e q u i r e d readjus tment du r ing t h e succeeding y e a r ' s o p e r a t i o n .

During t h e p r e l i m i n a r y t es t s , t h e p r e p a r a t i o n of t h e modi f ied ANfAMQ-9 radiosonde was determined t o be a n impor tan t p a r t o f a good ADP sounding. The commutator must be c leaned w i t h a "pink p e a r l " o r s o f t p ink e r a s e r immediately b e f o r e use . The s l i g h t t a r n i s h i n g of t h e gold commutator which occurs over a pe r iod of a few days causes e r r a t i c me teo ro log ica l da t a t o be t r a n s m i t t e d from t h e rad iosonde .

V I . CONCLUS IONS

This r e p o r t has shown t h a t t h e F r i e z Model 1146450 Radiosonde Automatic Data P rocesso r , when used w i t h t h e modif ied ANfAMQ-9 r a d i o - sonde, w i l l r e l i a b l y process t h e t r a c k i n g and m e t e o r o l o g i c a l d a t a f o r t r a n s f e r t o a computer. The approach u s i n g r e f e r e n c e i d e n t i f i e r s eg - ments on the rad iosonde commutator provides a means of decommutation i n t h e presence of s i g n a l f ad ing c o n d i t i o n s .

1 0

FIGURE 1 . RADIOSONDE AUTOMATIC DATA PROCESSOR WITHIN SLANT RANGE PRINTER

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12

FIGURE 3 . RADIOSONDE C O M M U T A T O R FOR A D P S Y S T E M

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B IBLIOGEUPHY

Other NASA Technical Memoranda on Na tu ra l Environment S t u d i e s publ ished by t h e Aero-As t rophys ics Off i c e , Acro-As trodynamics Laboratory, George C. Marshal l Space F l i g h t Center , H u n t s v i l l e , Alabama.

1.

2.

3.

4.

5.

6 .

7.

8.

9.

10.

11.

1 2 .

TM X-53003, "Proposed S o l u t i o n t o t h e Geomagnetic Anomalies i n t h e Ionosphere," Will iam T. Roberts , September 1963.

TM X-53009, " D i r e c t i o n a l Wind Component Frequency Envelopes , Cape Kennedy, F l o r i d a , A t l a n t i c M i s s i l e Range," 0. E. Smith and Glenn E. Daniels , February 1964.

TM X-53103, "Temperature Measurements I n s i d e a Rawinsonde Balloon," George T. 'Norwood, February 1964.

TM X-53018, "Space Rad ia t ions : A Compilation and Discussion," W . T. Roberts , March 1964.

TM X-53021, " D i r e c t i o n a l Wind Component Frequency Envelopes, Santa Monica, C a l i f o r n i a , P a c i f i c M i s s i l e Range," 0. E. Smith and Glenn E. Daniels , March 1964.

TM X-53023, " T e r r e s t r i a l Environment (C l ima t i c ) C r i t e r i a Gu ide l ines f o r Use i n Space Vehicle Development, 1964 Revis ion," Glenn E. Daniels , March 1964.

TM X-53027, "Cape Kennedy Low Level Wind Study f o r September 23-25, 1963," C a r r o l l H a s s e l t i n e , A p r i l 1964.

TM X-53037, " In t e rpa rame te r S t a t i s t i c a l Ana lys i s of Su r face Wind Speed, T o t a l Opaque Cloud Cover, and Maximum Wind Speed A l o f t a t Cape Kennedy, F lo r ida , ' ' 0. E. Smith, Lawrence E . Truppi and Harold L. Crutcher, A p ' r i l 1964.

TM X-53040, "Atmospheric Environment f o r S a t u r n (SA-5) F l i g h t Test ," J. W. Smith, A p r i l 1964.

TM X-53062, "An Automated Model f o r P r e d i c t i n g Aerospace Dens i ty Between 200 and 60,000 km Above t h e S u r f a c e of t h e E a r t h , " Robert E. Smith, June 1964.

TM X-53064, " L a t e s t Wind Es t ima tes from 80 km t o 200 km A l t i t u d e Region a t Mid-Latitudes ,I' W. T. Rober t s , June 1964.

TM X-53089, "Study of Sphere Motion and Bal loon Wind Sensors ," Paul B. MacCready, Jr . and Henry R. J e x , Ju ly 1964.

20

BIBLIOGRAPHY (Concluded)

13. TM X-53104, "An Automated Model f o r P r e d i c t i n g the K i n e t i c Tempera- t u r e of t he Aerospace Environment from 100 t o 60,000 Ian Above t h e Surface of t he Ear th ," Robert E. Smith, August 1964.

14. TM X-53115, "Deta i l s of Wind S t r u c t u r e from High Resolu t ion Bal loon Soundings," Robert S t in son , A. J. Weinstein and R. E. Reiter, August 1964.

15. TM X-53116, "An Empir ical Analysis of Dai ly Peak Surface Wind a t Cape Kennedy, F l o r i d a , f o r P r o j e c t Apollo," J. David L i f s e y , August 1964.

16. TM X-53118, " D i s t r i b u t i o n of Surface Meteoro logica l Data f o r Cape Kennedy, F lo r ida , " J. W. Smith, August 1964.

1 7 . TM X-53119, "Pre l iminary Cape Kennedy Atmospheric Data f o r Nuclear o r Toxic P a r t i c l e s Dispers ive S t u d i e s (August 1962 - Ju ly 1963)," C. K. H i l l , August 1964.

18. TM X-53124, "Lunar Environment: An I n t e r p r e t a t i o n of t h e Sur face of t h e Moon and Its Atmosphere," John R. Rogers and Otha H. Vaughan, September 1964.

19. TM X-53125, "Far-Field Sound Propagat ion a s Related t o Space Vehicle S t a t i c Tes t ing ," 0. E. Smith and D. G. M c B r i d e , September 1964, (pending r e l e a s e f o r d i s t r i b u t i o n ) .

20. TM X-53139, "A Reference Atmosphere f o r P a t r i c k AFB, F l o r i d a , Annual (1963 Revis ion) , " 0. E. S m i t h and Don K. Weidner, September 1964.

21. TM X-53142, "Space Environment C r i t e r i a Guide l ines f o r U s e i n Space Vehicle Development," Robert E. Smith, September 1964.

22. '1M X-53147 , "An U 1 tra-Low Frequency Elec t romagnet ic Wave Force Mechanism f o r t he Ionosphere," W. T. Roberts and J. M. Boyer, October 1964.

23. TM X-53167, "The Mar t ian Environment," Robert B. Owen, November 1964.

21

December 22 , 1964 APPROVAL NASA TM X-53186

RADIOSONDE AUTOMATIC DATA PROCESSING SYSTEM

By Robert E. Turner and Richard A. Jendrek

The informat ion i n t h i s r e p o r t has been reviewed f o r s e c u r i t y c l a s s i f i c a t i o n . Review of any in fo rma t ion concern ing Department of Defense o r Atomic Energy Commission programs has been made by the MSFC S e c u r i t y C l a s s i f i c a t i o n O f f i c e r . This r e p o r t , i n i t s e n t i r e t y , has been determined t o be u n c l a s s i f i e d .

This document has a l s o been reviewed and approved f o r t e c h n i c a l accu racy .

Chief , Aero-As t r o p h j s i c s Off i c e

E. D. G e i s s l e r D i r e c t o r , Aero-As trodynamics Labora tory

22

D I S T R I B U T I O N

R - D I R M r . We idner

R- S A - D r . K u e t t n e r

R-ASTR D r . Haeussermann

R- P & v E M r . C l i n e

R- COMP M r , Harness (I)

R-TEST M r . H e i m b u r g (2) D r . S ieber M r . Thornton M r . Tedrick D r . R e i s i g

R-QUAL M r . G r a u

MS-T - Roy B l a n d

I -MT M r . L. N y b o (2)

M S - I P L (8)

HME-P

MS - I P

P A T

I - V - D I R

I - E - D I R

AST-S D r . Lange

DEP-T D r . R e e s

R-AERO D r . G e i s s l e r M r . Jean M r . D a h M r . H o r n M r . Stone D r . Spee r M r . Lindberg M r . W. V a u g h a n (2) M r . 0. E. S m i t h (2) M r . J. W. S m i t h M r . Scoggins M r . Kaufman D r . H e y b e y M r . M c N a i r M r . H o l d e r e r M r . D a n i e l s M r . R. Tu rne r (25) M r . R. E. S m i t h M r . R. S c h o w M r . M c B r y d e M r . L i f s e y M r . deFr i e s

MS -H

cc-P

I - D I R

I-I/ I B - D I R

23

EXTERNAL DISTRIBUTION

NASA, F l i g h t Research Center Box 273 Edwards , C a l i f A t tn : M r . M. A . Covington

NASA, Ames Research Center M o f f e t t F i e l d Moun ta i n View, Ca 1 i f . A t t n : D i rec to r

M r . W. P. N e l m s

P a c i f i c M i s s i l e Range P o i n t Mugu, C a l i f . 93041 Geophysics Div. A t tn : M r . T . R. Ca r r , Code 3251, Box 2 2

M r . E . Masterson, Code 3150, Box 7

Naval Ordnance Tes t S t a t i o n China Lake, C a l i f . , 93557 At tn : M r . Royal C. Gould, Code 3069

M r . A r l i n J. Krueger, Code 50

O f f i c e of Naval Weather S t a . Washington Naval S t a . Washington D. C . , 20390 At tn : C d r . W . S . Houston, Jr .

(Navy Yard Annex)

Upper A i r Equipment Branch Bureau of Naval Weapons Washington, D. C. A t tn : M r . A . Lewis M i l l e r ( 2 )

O f f i c e of Naval Research Washington 2 5 , D . C. A t t n : M r . Henry Demboski, Code 421

P h y s i c a l Science Lab. , Army Missile Command Redstone Arsena l , Ala. A t tn : M r . Hubert D. Bagley

AMC Technical L i b r a r y Reds tone Arsena l , Ala.

U. S. Army E l e c t r o n i c s Labs. F o r t Monmouth, N . J. At tn : M r . Kenneth C. Steelman, AMSEL-RD-SM

M r . LaBedda, Me teo ro log ica l Div. , ( 2 )

24

EXTERNAL DISTRIBUTION (Continued)

U. S. Army E l e c t r o n i c s Research & Development A c t i v i t y White Sands M i s s i l e Range, N. W., 88002 At tn : M r . K. R. J enk ins , SELWS-MR

M r . W. L. Webb, SELWS-M

Commander 433L AWSPO (ESSW) 424 Trape lo Rd. Waltham 54, Mass.

A i r Force Cambridge Research Lab. L. G. Hanscom F i e l d , Bedford Mass. At tn : M r . Robert S. S l a v i n (3), Code CRE

A i r Force Cambridge Research Lab. 1065 Main S t . Waltham 54, Mass. At tn : M r . Robert Levi ton (4) , Code CRER

A i r Weather S e r v i c e (MATS) U. S. A i r Force S c o t t A i r Force Base, Ill. At tn : Commander (2)

M r . V. S. Hardin AWSSS (2) L t . Col. McIntyre , AWSMME L t . Col. H. S tevens , AWSOP

S t a f f Me t eoro log is t A i r Force E a s t e r n Tes t Range Det. 11 , 4 t h Weather Group Pa t r i c k AFB, Fla . Attn : L t . Col. Montague (2)

S t a f f Me t e o r o l o g i s t A i r Force Western T e s t Range Vandenberg AFB, C a l i f . At tn : L t . Col. W. L. Dotson, WTW

A i r Proving Ground Center E g l i n AFB, F la . , 3542 At tn : Maj. Ralph R. Ruyle, Code PGGW

A i r Force F l i g h t T e s t Center Edwards A i r Force Base C a l i f . , 93523 At tn : S t a f f Me teo ro log i s t

25

EXTERNAL DISTRIBUTION (Continued)

A i r Force Systems Command Andrews A i r Force Base, Md. At tn: Commander (2)

O p t . James G i r a y t y s , Code SCW

O f f i c e of S t a f f M e t e o r o l o g i s t AFSC (SCWTS) Andrews A i r Force Base Washington, D . C . , 20331

Headquarters NASA Washington 25, D. C. A t tn : Of f i ce of Advanced Research & Technology

D i r e c t o r M r . D. A. G i l s t a d

Of f i ce of Space Sc ience & A p p l i c a t i o n s D i r e c t o r D r . M. Tepper M r . W. Spreen ( 2 ) , Code FM

O f f i c e of Manned Space F l i g h t D i r e c t o r M r . P h i l Bolger , Code MGO

Kennedy Space F l i g h t Center Cape Kennedy, F l a . Attn: M r . Send le r

M r . Wilkins on M r . T a i a n i M r . Deese M r . Poppel L t . Col. Pe t rone D r . H. Gruene M r . L. Keene (2) L t . Col. R. C la rk D r . Knothe M r s . R u s s e l l , Tech. Lib.

S c i e n t i f i c & Techn ica l I n f o . F a c i l i t y (25) P. 0. Box 5700 Bethesda, Md. At tn : NASA R e p r e s e n t a t i v e (S-AK/RKT)

26

EXTERNAL DISTRIBUTION (Continued)

NASA Manned S p a c e c r a f t Center Houston, Texas At tn : D i r e c t o r

NASA Langley Research Center Langley F i e l d , Va. A t t n : D i r e c t o r

L i b r a r i a n M r . H. Tolefson , Mail Stop 240

NASA Lewis Research Center Cleve land , Ohio Attn: D i r e c t o r

M r . A. C. Hahn M r . J. W. Blue

NASA Wallops S t a . Wallops I s l a n d , Va. A t t n : D i r e c t o r

M r . J. Spur l ing

Richard A . Jendrek (25) Bendix F r i e z Div. Bend i x Corpora t i o n Bal t imore , Md.

Sandia Corp. Sandia Base Albuquerque, N . M . , 87115 At tn : M r . C l i f f o r d A . Olson, 7243-1

M r . La r ry Smith

S t a f f M e t e o r o l o g i s t (BSOW) A i r Force B a l l i s t i c Systems D i v . Norton A i r Force Base, C a l i f . At tn : Capt. K. L. P i t c h f o r d

DATAC Div. U. S. Weather Bureau Washington, D. C. A t tn : M r . Vaughan D. Rockney (3)

27

EXTERNAL DISTRIBUTION (Continued)

America Meteorologica 1 S o c i e t y M r . Spengler , Execut ive S e c r e t a r y 45 Beacon S t . Boston, Mass.

D i r e c t o r N a t i o n a l Center f o r Atmospheric Research Boulder , Colorado

U. S. Weather Bureau Washington 25, D. C. A t t n : D r . Robert M. White, Chief

M r . K. Nagler , S p a c e f l i g h t Meteorology Group

Pan American World Airways P a t r i c k AFB, Fla . A t t n : M r . Gerald Finger

M r . 0. H. Daniel

D r . 0. M. Essenwanger AOMC Research Lab.

Reds tone Arsenal , Ala. ORDMX-RRA

D r . Thomas A. Gleeson Dept. of Meteorology F la . S t a t e Univ. T a l l a h a s s e e , F l a .

D r . Hans Panofsky Dept. of Meteorology Pennsylvania S t a t e Univ. S t a t e Col lege, Pa.

Headquarters U. S . A i r Force Washington 2 5 , D. C. A t t n : L t . Col. D . J . Eddleman, AFSSA-ES-3

L t . Col. W. R. G o m e l , AFRDR-AS L t . Col. Leon Stone, AFRDR-AS

28