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V I I LONGITUDES AND LATITUDES PROGRAM The Markowitz Dual Rate Moon P o s i t i o n Camera
LONGITUDES AND LATITUDES PROGRAM Page A. Organization of Technical Panel on Longitude and Lat i t u d e 317 B. Summary of Panel Actions 317 C. Project Objectives and Results 318 7.1 Longitude and La t i t u d e S t a t i o n , Hawaii 319 Longitude and Lat i t u d e Stations a t Washington and San Diego 320 316
V I I . LONGITUDES AND LATITUDES A. Organization of Technical Panel on Longitude and Lat i t u d e 1. Establishment of the Panel. I n v i t a t i o n s f o r membership on the Panel were sent i n l a t e 1954 to s c i e n t i s t s a c t i v e i n t h i s f i e l d . Dr. Wi l l i a m Markowitz was elected Chairman a t the f i r s t meeting. The Panel make-up was as fol l o w s : 2. Composition o f the Panel. ( A f f i l i a t i o n a t time of appointment.) a. Panel Members C. I . Aslakson G.M. Clemence U.S. Naval Observatory W i l l i a m Markowitz (Chairman) U.S. Naval Observatory D. A. Rice U.S. Coast and Geodetic Survey b. Consultants CO. Al e x i s F.W. Hough O.W. Williams c. S e c r e t a r i a t (IGY S t a f f ) W.M. Smith ( u n t i l June 1956) P.W. Mange ( u n t i l Sept.1959) P.J. Hart ( a f t e r Sept. 1959) O f f i c e of Naval Research Army Map Service Geophysics Research D i r e c t o r a t e , AFCRL 3. Panel Meetings. Only one meeting was held; a l l f u r t h e r matters were taken up by m a i l . F i r s t Meeting A p r i l 29, 1955 Washington, D.C. B. Summary of Panel Actions 1. I n i t i a l CSAGI Program. F i r s t plans f o r the IGY program were b u i l t around the moon camera designed by Dr. W i l l i a m Markowitz, U.S. Naval Observatory, which was to be used at s u i t a b l y equipped observatories around the world, on a cooperative basis to photo- graph the moon and obtain p r e c i s i o n lunar p o s i t i o n s . The program was designed to im- prove geodetic determinations, provide f o r connection of geodetic datums, and to pro- vide i n f o r a a t i o n r e l a t i n g to the v a r i a t i o n i n time stemming from I r r e g u l a r i t i e s i n the earth's r o t a t i o n . The planned program also included conventional observation of ast r o - nomical longitude and l a t i t u d e w i t h astrolabes and photographic zenith tubes. 2. Development of U.S. Program. At the only meeting o f the Panel, the program of the U.S. Naval Observatory was discussed wherein twenty moon cameras would be furnished by the Naval Observatory, seventeen of which would be loaned to observatories i n other countries f o r observations. Special measuring engines f o r reduction of the plates were to be b u i l t , three of which would be loaned to other groups f o r data reduction. I t was also decided t h a t the Danjon Impersonal astrolabe would be used a t three U.S. s t a t i o n s , one i n Hawaii, one i n or near San Diego, and one at the Naval Observa- t o r y , Washington D.C. The CSAGI recommended plan was considered s a t i s f a c t o r y . The Panel decided t h a t i n s t r u c t i o n s would be furnished w i t h each moon camera and measuring engine, and t h a t no general i n s t r u c t i o n manual would be required. 317
LONGITUDES AND LATITUDES C. Proje c t Objectives and Results 1. Siimmarv of Program. The longitude and l a t i t u d e program consisted of two parts: (a) astronomical longitudes and l a t i t u d e s w i t h Danjon impersonal astrolabes; and (b) the moon p o s i t i o n program. Astrolabe measurements and moon p o s i t i o n photographs were made a t San Diego, Washington, and Hawaii. The photographic plates from these s t a t i o n s and other cooperative s t a t i o n s were measured and reduced by the U.S. Naval Observatory. 2. Projects. One numbered p r o j e c t , which provided f o r the establishment and opera- t i o n of the s t a t i o n a t Hawaii, and a contri b u t e d p r o j e c t are described i n the f o l l o w - ing pages. 318
LONGITUDES AND LATITUDES Pr o j e c t 7.1 - Longitude and La t i t u d e S t a t i o n , Hawaii 1. Objectives. This work, undertaken by the U.S. Coast and Geodetic Survey, provided f o r a p r e c i s i o n s t a t i o n i n Hawaii f o r operation of the Markowitz moon camera and Danjon astrolabe. Along w i t h the other s t a t i o n s a t San Diego and Washington, the observations would provide a p r e c i s i o n base-line datum from Washington, through San Diego, t o Hawaii. 2. Operations. L t . Taylor and L t . Garcia were t r a i n e d a t the Naval Observatory i n the use of the moon camera and the Danjon astrolabe. They then proceeded to Hawaii, stopping en route a t San Diego State College, San Diego, C a l i f o r n i a , to a s s i s t i n esta- b l i s h i n g the s t a t i o n there, which was operated by personnel from the College. I n Hawaii, i t was found to be impossible to make the observations a t the o l d l o n g i - tude s t a t i o n , l a s t occupied i n 1926, and a new s t a t i o n was constructed on Navy property near Honolulu. Dr. Markowitz v i s i t e d the i n s t a l l a t i o n I n January 1958 and observations began on January 23, 1958. During the course of the observations, some problems were encountered w i t h wind, and a wind break was constructed to reduce v i b r a t i o n of the telescope. 3. Personnel. D.A. Rice was p r o j e c t supervisor; the s t a t i o n a t Hawaii was under the d i r e c t i o n o f L t . E.A. Taylor, w i t h L t . H.A. Garcia as associate observer u n t i l Decem- ber 1958. Operations were d i r e c t e d by L t . Garcia during 1959. 4. Results. This p r o j e c t was mainly f o r the c o l l e c t i o n o f data, which were reduced a t the Naval Observatory. During the operations i n 1958 and up u n t i l t ermination of observations i n December 1959, 311 sets of moon camera plates were obtained, and many successful consecutive observation sets were obtained w i t h the Danjon astrolabe. 5. Bibliography. E.A. Taylor: " I n t e r i m Project Report, Hawaiian S t a t i o n , Longitude and L a t i t u d e , J u l y 1957 - October 1958," (manuscript, U.S. Coast and Geodetic Survey, 1958). 319
LONGITUDES AND LATITUDES Longitude and Latitude Stations a t Washington and San Diego 1. Obiectives. These stati o n s were operated by the Naval Observatory and San Diego State College, r e s p e c t i v e l y , as c o n t r i b u t i o n s to the IGY program. The moon camera and astrolabe observations permitted analysis f o r information on time changes connected w i t h i r r e g u l a r i t i e s i n the earth's r o t a t i o n , and geodetic values. 2. Operations. I n a d d i t i o n to establishment of the s t a t i o n a t San Diego, and i n s t a l - l a t i o n and operation of equipment a t Washington, the Naval Observatory, through the cooperation o f the O f f i c e o f Naval Research, supplied cameras f o r the f o l l o w i n g obser- v a t o r i e s : Canberra, A u s t r a l i a ; Cape, Republic of South A f r i c a ; Curacao, Netherlands A n t i l l e s ; Greenwich (Herstmonceaux), England; Honolulu, Hawaii; N a i n i T a l , I n d i a ; Ottawa, Canada; Pans, France; Perth, A u s t r a l i a ; San Fernando, Spain; Sao Paulo, B r a z i l , Tokyo, Japan; H e l s i n k i , Finland; and Uppsala, Sweden, although a t these two l a s t l o c a t i o n s , observations were very d i f f i c u l t owing to the high l a t i t u d e . Measuring engines were supplied to the Cape, Greenwich and Paris observatories, as w e l l as t o the Naval Observatory. A t o t a l of about 3000 plates were measured. Reduction a t the U.S. Naval Observatory was under the d i r e c t i o n of R.G. H a l l . The data obtained included the lunar apparent r i g h t ascension and d e c l i n a t i o n r e f e r r e d to the mean equinox of date f o r the Universal Time of observation. These reductions have been d i s t r i b u t e d t o the observatories. I n order to obtain solutions of the data f o r Ephemeris Time and geocentric coor- dinates, corrections have to be made f o r lunar limb i r r e g u l a r i t i e s ; t h i s process i s now underway. Data from the astrolabe, PZT and other instruments are being reduced and analysed at the Bureau I n t e r n a t i o n a l de I'Heure, Pans. 3. Personnel. Observations and reductions a t the Naval Observatory were made under the supervision of Wi l l i a m Markowitz, R.G. H a l l , and R.A. Medford. Observations a t San Diego State College were supervised by C l i f f o r d E. Smith. 4. Results. While corrections to the moon camera data are s t i l l being applied and f i n a l analysis i s not completed, the program has had some r e s u l t s , notably the precise determination of the frequency of the cesium-beam atomic o s c i l l a t o r , i n cooperation w i t h the National Physical l.aboratory, Teddington, England, This important physical constant was found to be 9 192 631770 + 20 cycles per second of Ephemeris Time. One of the early r e s u l t s of the longitude program was the r e v i s i o n by the BIH of the conventional longitudes of the various n a t i o n a l time services, necessitated by the i n t e r n a t i o n a l coordination of time s i g n a l transmissions. 5. Bibliography, W. Markowitz, N, Stoyko, E,P. Federov: "The IGY/IGC Longitude and Lat i t u d e Program," Symposium on the Results of the IGY/IGC ( i n press), MIT press. 320
