F — 100 551. 510. 535. 05(52) (047.3) IONOSPHERIC DATA IN JAPAN FOR  APRIL  1957 Vol. 9 No. 4 Issued in June 1957 Prepared by THE RADIO RESEARCH LABORATORIES KOKUBUNJI, TOKYO, JAPAN 551. 510. 535. 05(52) (047.3) IONOSPHERIC DATA in JAPAN FOR APRIL 1957 Vol. 9 No. 4 THE RADIO RESEARCH LABORATORIES KOKUBUNJI, TOKYO, JAPAN
CONTENTS

k—100
SYMBOLS AND TERMINOLOGY
In accordance with the First Report of the Special Committee on World-Wide Ionospheric Soundings (URSI/AGI), Brussels, September 2, 1956, there has been some revision of the procedures for production, reduction and presentation of ionograms and ionosphere characteristics. A number of modification in the standard scaling symbols and terminology are being made as given in the following list.
limit of the normal frequency range. Used in a qualifying sense, see blow. Measurement influenced by, or impossible because of, the presence of spread echoes.
Used as a preceeding symbol on monthly tabulation sheets. greater than…… D u less than……
Missing value has been replaced by an interpolated value. Ordinary component characteristic deduced from the extraordinary component. Value determined by a sequence of observations, the actual observation being inconsistent or doubtful. Uncertain or doubtful numerical value. U
SITES OF THE RADIO WAVE OBSERVATORIES
Ionospheric observation is carried out at the following four observatories in Japan.
Yamagawa Site Latitude Longitude Wakkanai shi, Hokkaido 45°23.6′N. 141°41.1'E. Wakkanai Tegata Nishishin-machi, Akita-shi, Akita-ken 39°43.5'N. 140°03.2'E. Koganei-machi, Kitatama-gun, Tokyo-to 35°42.4′N. 139°29.3'E. Kokubunji Yamagawa-machi, Ibusuki-gun, Kagoshima-ken 130°37.7'E. 31°12.5'N. Solar radio emission is observed at Hiraiso Radio Wave Observatory. Site Latitude Longitude 36°22.0'N. 140°37.5'E. Hiraiso-machi, Nakaminato-shi, Ibaragi-ken Hiraiso F ganei-machi, Kitatama-gun, Tokyo, Radio Research Laborator
NOSPHERIC
Vakkana Long. 141°41.1' 4 5° 2 3. 6'
foF2 20m, 30th, at the ground. olar eclipse continued from Lio — Ma to 22:00 Me in [3] A viousli [] Marual Ah 6
09h 20m, 30th, at the ground level. The Radio Research Laboratorie Koganei machi, Kitatama-gun, Tokyo, Japan
IONOSPHERIC DATA
Lat.     45°2 3.6' N Wakkanai W 2 7 Radio Research Labora ei-machi, Kitatama-gun, Tokyo
NOSPHERIC
Mean 35° E
4.5° 2.3.6' ong. 141°41.1' Apr.1957
3000)F2

2011, 30th, at the ground level (3000)F 1.9 .... Mc to
The Radio Research Laboratories Koganei-machi, Kitatama-gun, Tokyo, Japan Radio Research Labora ci-machi, Kitatama-gun,
NOSPHERIC
akkana
Lat. ong. 141°41. 45°2 3, 6' lu
20m, 30th, at the ground . Me in la Sha Ma toエス・ロ□ Marval Lat. Long, 141°41,1'B Wakkanai The Radio Research Laboratories Koganei-machi, Kitatama-gun, Tokyo, Japan
ONOSPHERIC DATA

□ Marvel Bweep   /:こ Mc to types of Es Note: Solar eclipse continued from 07h 16m to 
        09h 20m, 30th at the ground level. W 6 ei-machi, Kitatama-gun,-Tokyo e Radio Research Labora
DAT
NOSPHERIC
Time Mean 35° E foF2 Apr.1957 39° 43.6' tat. 140° 08.2° Long. k i t : A .
ar eclipse continued from O7h foF2 .c Mc to 22.0 ... Mc min ] Marual [ ] A woma 12 is I Koganei-machi, Kitatama-gun, Tokyo, Japan, The Radio Research Laboratories
ONOSPHERIC DATA
A k i t a Tat. 39°43.5' Na
09h 01m, 30th, at the ground level. foEs Ewer 2.85. Me to 22.0. Me in _ 2 __ min □ Marual A 2 13 e Radio Research Labora ti-machi, Kitatama-gun,
IOSPHERIC
Time Mean 135° E Lat. 39° 43.5' long。 140° 03.2 k i t a Apr.1951 (3000)F2
13000F2 at the ground ar eclipse continued from OTh h 01m, 30th, Mc to 22:0_Mc in 0.85 ■ Manal [ ] A u t r m a l V E The Radio Research Laboratories Koganei-machi, Kitatama-gun, Tokyo, Japan
Akit nti-machi, Kitatama-gun, Tokyo,とsy
NOSPHERIC
35° E Mean be Radio Research Laborat
39h Olm, 30th, at the ground level Apr.1957
Mc to 22.0  Mc in口Marval [ ] A wor P S Koganei-machi, Kitatama-gun, Tokyo, Japan The Radio Research Laboratorie A k i t a Izat. Long, 140° 03.2°E 39°43.5' N ONOSPHERIC DATA
types of Es Note: Solar eclipse continued from 07h 09m to
000 09h 01m, 30th, at the ground level. Brows 9:85 - Mc to 22:0 - Mc in - - - - rain [] Manual A
foF2 nci-machi, Kitatama-gun, The Radio Research Laborato
NOSPHERIC
Mean 35° E kubunji Tol 3 5° 4 2, 4' ong. 1 3 9° 29, 3' Apr.195
Koganei-machi, Kitatama-gun, Tokyo, Japan The Radio Research Laboratories Bweep _ foFl Note: Solar eclipse continued from 07h 07m to
a □ Marval 19 Lat. 35°42.4' Long, 139° 29.

NOSPHERIC
nei-machi, Kitatama-gun, Tokyo, The Radio Research Laborato Lat.     3 5° 4 2.4° N Long. 1 3 9° 29.3° E okubunji Tokyo
DNOSPHERIC DATA
The Radio Research Laborator Koganei machi, Kitatama-gun, Tokyo, Japan
. . . foEs OBh 45m, 30th, at the ground level. [ ] A s tomatio  気DAT
Long. 1 3 9° 29.3' anci-machi, Kitatama-gun, Tokyo Radio Research Laborat NOSPHERIC fbEs
Koganei-machi, Kitatama-gun, Tokyo, Japan The Radio Research Laboratoria
ONOSPHERIC DATA
Kokubunji Tokyo Long. 139° 29.3' E Lat. 35°42.4' } Apr.1957
t-min OBh 45m, 30th, at the ground level. Prosp _ L _ L __ Mc to _ L _ L __ Mc tin __ L _ ■ Manal K 9 Radio Research Labora i-machi, Kitatama-gun,
35°42.4' Long, 139° 29,3 Lat. 3000F2
NOSPHERIC

Apr.195 The Radio Research Laboratories Koganei-machi, Kitatama-gun, Tokyo, Japan
OBh 45m, 30th, at the ground level. nei-machi, Kitatama-gun, Tokyo, Jap he Radio Research Laboratories
ONOSPHERIC. DATA

Lat. 35°42.4' Koganei-machi, Kitatama-gun, Tokyo, Jap he Radio Research Laborati
ONOSPHERIC DATA
lokubunji Tokyo Lat. 35°42.4' N Long, 1 3 9 ° 29, 3 ' b
h'F Apr.1957 Osh 45m, 30th, at the ground level, h'F □ Marval I:O __ Me to K 3.5° 4.2.4° Long, 139° 23, Lat.
okubunji Toky
nei-machi, Kitatama-gun, Tokyo e Radio Research Labora DAT NOSPHERIC 35° E   Mean
k'Es Apr.1957 45m, 30th, at the ground lev k'Es ro - L L Me to [4] A s tone ] Manual
S II Koganei-machi, Kitatama-gun, Tokyo, Japan The Radio Research Laboratories
ONOSPHERIC DATA

Lat. 35°42.4' N Long. 139° 29.3° E Kokubunji Tokyo Swoop   / types of Es Oeh 45m, 30th, at the ground level A Automatic ■ Marrad K 12 ei-machi, Kitatama-gun, Tokyo, Radio Research Labora
NOSPHERIC

3 5° 4 2. Long. 139° 29. Lat.
hpF2 Apr.1957 Long. 1 3 9° 29.3' E_ Lat. Kokubunji Tokyo Koganei-machi, Kitatama-gun, Tokyo, Jspan The Radio Research Laboratoria
ONOSPHERIC   DATA
yp F2 Apr.1957
ypF2 Solote: Solar eclipse continued from 07h 07m to Osh 45m, 30th, at the ground level. mp L-D-Mc to LZ: A Mc in [] Manal A A Automatic K 14 31 foF2 i-machi, Kilatama-gun, Tokyo, Radio Research Labor
IOSPHERIC

a m a g a w Ong. 130°37. 31° 12. Lat Apr.1951 ar eclipse continued from Oh foF2 ___ □ Marush [4] A mon A I The Radio Research Laboratories Voganei-machi, Kitatama-gun, Tokyo, Japan
ONOSPHERIC , DATA
amagawa Lat. 31°12.5'N Long, 130°37,7'B foEs
Ceh 29m, 30th, at the ground lovol, foEs - _ □ Manual 33 i-machi, Kitatama-gun, Tokyo, Radio Research Labora
IOSPHERIC
Time Moan 35° E 31°12, lat. a maga w ong. 130°37. Apr.1957 13000F2
__ Mc to 20.0__ Mc in , 13000F 29m, 30th, at the ground [4] Automa   A 3 Voganei-machi, Kitatama-gun, Tokyo, Japan The Radio Research Laboratories
IONOSPHERIC DATA

Lat.   31° 12.5° N
e Radio Research Labora ti machi, Kitatama-gun,
NOSPHERIC
s a maga w at. ong. 130°ST. 31°12. leve 06h Solar eclipse continued from Eh 29m, 30th, at the ground 1. S. . . Mc t»ミロロ. . Mc in ] March 🇨🏻 A ethone A S Yoganei-machi, Kitatama-gun, Tokyo, Japan The Radio Research Laboratories ONOSPHERIC ・ DATA Lat. 31° 12, 6' N Long. 130°37.7' B Yamagawa
Oth 29m, 30th, at the ground level. types of Es [] Marval __ min ep -1,0 — Mc to 20,0 — Mc in — 1
APR.
Observing Station:  HIRAISO Flux in 10-22v.m.-2(c/s)-1, 2 polarizations Frequency: 200 Mc/s. Time in U.T.
Noise Storms: 8th 2250 ~ 9th near sunset (gradually decaying) 27th 2040 ~ sunset (slight storm) 28th sunrise ~ 2330 (slight storm) 29th 2320 (Observation started) ~ sunset IONOSPHERIC DATA IN JAPAN FOR APRIL 1957外9巻  外 4 号測　報　告部部提