C5-^-/5-/F. ■ /^^ -jrrs 10^' 
 
 ESSA TR ERL 162-ITS 104 
 
 A UNITED STATES 
 DEPARTMENT OF 
 
 COMMERCE 
 
 PUBLICATION 
 
 
 ESSA Technical Report ERL 162-ITS 104 
 
 U.S. DEPARTMENT OF COMMERCE 
 Environmental Science Services Administration 
 Research Laboratories 
 
 An Atlas of Oblique-Incidence 
 High-Frequency Backscatter lonograms 
 of the Midlatitude Ionosphere 
 
 ROBERT D. HUNSUCKER 
 
 BOULDER, COLO. 
 MARCH 1970 
 
ESSA RESEARCH LABORATORIES 
 
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.<tA£NTo^ 
 
 ^'^'(HCl Sl*^^^'''' 
 
 U.S. DEPARTMENT OF COMMERCE 
 Maurice H. Stans, Secretary 
 
 ENVIRONMENTAL SCIENCE SERVICES ADMINISTRATION 
 
 Robert M. White, Administrator 
 RESEARCH LABORATORIES 
 Wilmot N. Hess, Director 
 
 ESSA TECHNICAL REPORT ERL 162-ITS 104 
 
 An Atlas of Oblique-Incidence 
 High-Frequency Backscatter lonograms 
 of the Midlatitude Ionosphere 
 
 ROBERT D. HUNSUCKER 
 
 >> INSTITUTE FOR TELECOMMUNICATION SCIENCES 
 
 J BOULDER, COLORADO 
 
 ^ March 1970 
 
 
 
 For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington, 0. C. 20402 
 
 Price $1.25 
 
TABLE OF CONTENTS 
 
 Page 
 
 ABSTRACT 1 
 
 1. INTRODUCTION 1 
 
 2. RANGE -AZIMUTH AND RANGE-ELEVATION 
 
 SCAN BACKSCATTER 5 
 
 3 2.1 Equipment Parameters 5 
 
 2. 2 Classification of Ech(;es 8 
 
 3. RANGE-AZIMUTH SCAN BACKSCATTER 29 
 
 4. RANGE-TIME BACKSCATTER 39 
 
 5. SWEEP-FREQUENCY BACKSCATTER 63 
 
 6. PPI ROTATING ANTENNA, FIXED FREQUENCY 
 BACKSCATTER 87 
 
 7. ACKNOWLEDGMENTS 105 
 
 8. REFERENCES 105 
 APPENDIX 109 
 
 iii 
 
Digitized by the Internet Archive 
 
 in 2012 with funding from 
 
 LYRASIS IVIembers and Sloan Foundation 
 
 http://archive.org/details/atlasofobliqueinOOhuns 
 
AN ATLAS OF OBLIOUE-INCIDENCE HIGH-FREQUENCY 
 BACKSCATTER lONOGRAMS OF THE MIDLATITUDE IONOSPHERE 
 
 Robert D, Hunsucker 
 
 An atlas of data photographs of (jblique- incidence 
 high-frequency (HF) backscatter ionograms of t±ie nnid- 
 latitude ionosphere from the period 1952 - 1969 is pre- 
 sented. Representative examples of data acquired by 
 the range-azimuth scan, range- elevat icm scan, range- 
 time, sweep- frequency and PPI backscatter techniques 
 are displayed. No attempt is made to interpret the back- 
 scatter "signatures", but publications which present 
 analyses and interpretations of backscatter data are 
 referenced . 
 
 Key Words: Atlas, backscatter, data, high-frequency, 
 ionograms, ionosphere, midlatitude, 
 oblique -incidence, photographs. 
 
 1. INTRODUCTION 
 
 The purpose of this report is to present representative examples 
 of oblique incidence backscatter ionograms of the midlatitude ionosphere 
 obtained by several different high-frequency (HF) backscatter sounding 
 techniques. The atlas consists of five data photosections and an 
 appendix. Each section contains a description of a particular technique, 
 a listing of pertinent equipment parameters, a saniple data format and 
 a collection of photographs of the particular cathode -ray-tube (CRT) 
 data display. Other similar atlases have been published by Wright 
 andKnecht (1957) and by Agy et al. (1959). 
 
 The HF backscatter technique for oxploriiig tlie ionosphere was 
 pioneered by Edwards and Jansky (1941), Benner (1949), Kono (1950), 
 Hartsfield et al.(l950), Dieminger (1 951), Peterson (1^51), Abel and 
 Edwards (1951), Villard and Peterson (1952), and Silber stein (1954). 
 This technique continues to provide scientists with new and iniportant 
 information on the physics of the ionosphere and the nature of the 
 
surface of the earth. Basically, the method utilizes an HF pulse trans- 
 mitter and a suitable antenna to illuminate the ionosphere, and a sensi- 
 tive receiver to detect the signal after it has been refracted in the 
 ionosphere, backscattered from the earth and returned via the ionosphere 
 to the receiving antenna. Direct backscatter from electron -density 
 irregularities in the high-latitude ionosphere has also been described 
 by Bates (I960, 1965), and applications of HF backscatter information 
 
 for improving high -latitude HF predictions have been recently reported 
 by Hunsucker and Bates (1969). 
 
 No attempt will be made to interpret the backscatter data in this 
 Atlas; instead, I hope that ionospheric physicists of the theoretical 
 persuasion, while wandering through this menagerie, may be attracted 
 to one or more of the exotic specimens and feel compelled to contrive a 
 rigorous, elegant, qviantitative , and thoroughly satisfying explanation. 
 For detailed analyses of various HF backscatter observations the reader 
 is referred to publications by Croft (1965); Bates (1966); Croft (1967); 
 Blair, Melanson^and Tveten (1969); Georges and Stephenson (1969); 
 Hxinsucker (I969);and papers referenced in the backscatter bibliography 
 by Hagn et al.(l961). 
 
 The five-digit number on the lower left of each page of most of 
 the ESSA. backscatter data is the number of the negative for that page, 
 which is on file in the Photographic Laboratory at the ESSA Research 
 Laboratories in Boulder, Colorado. Photographic prints of any figure 
 or figures may be obtained at a nominal charge by writing directly to 
 the Photographic Laboratory. 
 
 Table 1 lists five of the most commonly used techniques for ob- 
 taining HF backscatter information on the state of the ionosphere. It is 
 intended to convey some idea of the general characteristics and 
 capabilities of each of the listed techniques. 
 
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2. RANGE -AZIMUTH AND RANGE -ELEVATION SCAN BACKSCATTER 
 
 The backscatter data illustrated in this section were obtained 
 with the narrow-beam HF scan backscatter sounder installation at the 
 Institute for Telecommiinication Sciences (ITS) at the Boulder ESSA 
 Research Laboratories. Brief descriptions of some of the equipment 
 parameters may be found in publications by Fitzgerrell, Proctor^and 
 Wilson (1966), Hunsucker and Tveten (1967), and Tveten and Hunsucker 
 (1969), while a more complete documentation of the system has been 
 presented recently by Hunsucker (1969). 
 
 2.1 Equipment Parameters 
 
 The ITS HF scan radar is a bistatic system with the transmitter 
 located at Erie, Colorado (19 km southeast of the Table Mountain 
 receiving site). Because of the large propagation distances compared 
 with the separation between transmitter and receiver, however, this 
 sounder may be considered to be a monostatic system. The radar 
 system operates in the 9 to 2 5 MHz frequency range with pulse power 
 outputs between 10 and 100 kW. The nominal pulse repetition frequency 
 (PRF) is 20 pulses/ sec and the pulse length is 300 ^sec. Two trans- 
 mitting antennas are available for use: a single -wire terminated rhombic 
 with a center design frequency of 15 MHz directed toward 114", and a 
 rotatable horizontally polarized log periodic antenna. The rhonnbic anten- 
 na is characterized by a radiatic^n pattern with rather sharp nulls in azimuth 
 and elevation, whereas the log-periodic antenna has a very wide beam, 
 relatively uniform (lacking sharp nulls) in both azimuth and elevation. 
 
 High resolution in the receiving system is achieved by large - 
 aperture, linear, uniformly spaced arrays electromechanically scanned 
 in azimuth and elevation. Table 2 shows the important parameters of 
 the elevation and azimuth scan systei-n. 
 
 The geographical area scanned by the azimuth array as a function 
 
 of frequency is shown in fitiure 1. 
 
Table 2. System Parameters . 
 
 Azirauth Array (1392 ft aperture) 
 
 Elements: Log periodic horizontally polarized transposed dipoles 
 
 Frequency, 12-25 MHz 
 
 Gain, 5 dB above isotropic 
 
 Front -to-back ratio, 20 dB 
 
 E plane beamwidth, 72* 
 
 H plane beamwidth, 116* 
 Element spacing: 17. 67 m 
 Element height above ground: 24. 38 m 
 Bore sight azimuth: 114* true bearing 
 
 Horizontal Antenna 
 
 
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 Frequency 
 
 beamwidth 
 
 elevation 
 
 sector scan 
 
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 (deg) 
 
 (deg) 
 
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 15 2.3 
 
 18 2.0 
 
 21 1.7 
 
 25 1.4 
 
 14.8 
 
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 11.8 
 
 69 
 
 9.8 
 
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 8.4 
 
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 7.1 
 
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 Element spacing: First element 8 m above ground and remaining 
 
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 Bore sight azimuth: 114* true bearing 
 
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 elevation sector 
 
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 12 4.2 3-52 
 
 15 3.2 2.6-39 
 
 18 2.8 2.3-32 
 
 21 2.4 1.9-26 
 
 25 2.0 1.5-22 
 
2. 2 Classification of Echoes 
 
 This section contains many signatures observed using the ITS 
 high -resolution HF backscatter sounder, and illustrates nearly all of 
 the ground backscatter echo types encountered at this particular loca- 
 tion for both undisturbed and disturbed ionospheric conditions. An 
 attempt has been raade to categorize these signatures into seven or 
 eight generic types^'which have been given names roughly describing 
 their appearance on the range -azimuth record. Although the signatures 
 being described here apply to the azimuth scan record, the elevation 
 scan data are also included, and both are discussed in detail by 
 Hiinsucker (1969). On each of the data photos, an arrow points to the 
 signature being illustrated. 
 
 Page 11 shows examples of the "uniform" (U) backscatter 
 signature which is characterized by a band of relatively uniform inten- 
 sity at a constant range (or delay time). (The details of this particular 
 signature are somewhat obscured by a gain saturation effect). A signa- 
 ture designated as a "patch" (P) is shown on pages 12 and 13. It 
 generally has a roughly circular or elliptical shape, is always observed 
 at ranges less than the "uniform" echo, and always appears to move 
 approximately parallel to the range markers (left-to -right or right-to- 
 left). Pages 14 and 15 illustrate an echo described by the name "tilt" 
 (T), whose main identifying characteristic is its variation of range as 
 a fiinction of azimuth. Another often observed signature is shown on 
 page 16 and is called "bands" (B) because it consists of two or more 
 echoes structured in parallel bands which move in a direction perpendi- 
 cular to their major dimension. They always occur at ranges greater 
 than the "xiniform" signatures and ar6 never stationary. The signature 
 on page 17 is categorized as "large -size -blobs" (LB), since these 
 large echoes either remain in one position or drift slowly during their 
 
lifetime on the azimuth scan record. Similarly, the echoes shown on 
 
 page 18 display roughly equivalent nnovement characteristics to the 
 "LB" signature but the "blobs" are smaller, so they are labelled 
 "medium-sized-blobs" . 
 
 Pages 19 and 10 illustrate a phenomenon called "fine -structure" 
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 with typical fading periods from less than 12 sec to several min- 
 utes, and display no discernible motion. Intense, short-range echoes 
 which often saturate the azimuth-range display out to about 10 msec 
 are shown on page 2.1, which was recorded during the intense Leonid 
 meteor shower of November 15-17, 1966. The next signature illustrat- 
 ed in the "hook" (H) echo shown on pages 2Z and 23. This characteristic 
 shape is observed at various ranges and azimuths and represents one 
 of the more "pathological" signatures which have been observed. 
 Pages 24 through 27 show examples of miscellaneous unclassified 
 signatures. 
 
SAMPLE DATA FORMAT 
 
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 Geographic Azimuth Degrees above 
 
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 Mountain Standard Time (MST) = UT-7 Hours 
 
 Date (Doy-Month-Yeor) 
 
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 Type Transmitting Antenna , RH- Rhombic, 
 
 LP = Log Periodic 
 
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 The data displayed in this section are identical to the range - 
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 37 
 
4. RANGE -TIME BACKSCATTER 
 
 The data in the first part of this section were provided by 
 
 Professor I. Ranzi of Ccntro Radioelettrico Spcrimentale "G.Marconi", 
 
 in Rome, who has also furnished the following information on the 
 
 observing station: 
 
 Latitude and longitude: 42.02° N; 1 1 . 84* E 
 
 Peak pulse power: 2. 5 kW 
 
 Pulse repetition frequency: 16. 66 pulses/ sec 
 
 Pulse duration: 400 \i sec 
 
 Type of antenna: Four-element horizontal Yagi; gain r 7 dB, beamwidth 
 
 (-3dB)=56 , front -to- back gain ratios 33d B, height 
 above the sea = 15 m (the antenna tower is on the coast, 
 and all the first Fresnel zone of the reflected ray is on 
 
 the sea for direction NNW.) 
 
 On each of the records, time (15° east meridian time) increases from 
 left to right, and slant range (in kiloinctcrs) increases from bottom to 
 top. The operating frequency for all the data is 18, 6 MHz, and the 
 antenna azimutli is indicated on tlie left end of each film strip. Photo- 
 graphic negatives of each of the pages are on file at the ESSA Labora- 
 tories photographic laboratory. 
 
 The high resolution data photographs on pages 5 3-62 were 
 obtained by the CRPL backscatter project group (R . Silberstein, W.L. 
 Hartsfield and L. H. Tvctcn). These data were acquired during the 
 period 1953-1954 with an oblique backscatter sounder located at Sterling, 
 Virginia (Tveten, 1961). The salient system parameters are: 
 Peak pulse power : 200 to 500 kW 
 
 Pulse repetition frequency: 2 5 pulses/ sec 
 Pulse duration: 40 \j sec 
 
 Frequency: 13.7 MHz 
 
 Antenna: Two 3-clcment vertically polarized Yagis spaced \/ 2 apart 
 with the center oi the array -^^ - above ground. 
 
 Now the Institute for Teleconununication Sciences, ESSA. 
 
 39 
 
rJ 
 
 40 
 

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 58 
 
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 59 
 
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 60 
 
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 61 
 
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 62 
 
5. SWEEP-FREQUENCY BACKSCATTER 
 
 These data were obtained at ESSA' s Erie, Colorado^field site 
 during January through April 1963 using two different antennas. Pertin- 
 ent equipment parameters are shown on page 65, along with the sample 
 data fornnat. Pages 66-68 show soundings on the four cardinal geo- 
 graphic azimuths using the rotatable log -periodic antenna. Various 
 "signatures" obtained at different azimuths during winter and equinoctial 
 months of 1963 are shown on pages 69 through 8 3. The multiple traces 
 on the left of most of the data photos in this section are multiple vertical 
 incidence (V-I) echoes. The oblique backscatter echo is observed to 
 take off from the second-order vertical trace as explained by Peterson 
 (1951). The distorted nature of the V-I traces in the region of 1 . - 
 6. 5 MHz is due to the nature of the frequency-determining cam used in 
 this particular so\inder which resulted in transmission at a fixed fre- 
 quency of 6. 5 MHz in this section of the ionogram. 
 
 Pages 84-85 in this section display data obtained with the 
 high-resolution system described in section 2. The "wide -beam" data 
 were acquired using only one of the antennas of the 2 5-element horizontal 
 array; the narrow-beam data were recorded using the entire array. 
 These data arc included to illustrate how a narrow antenna beam shows 
 the ionospheric "fine -structure" at midlatitudes. 
 
 No attempt has been made to classify the echoes in this section 
 as was done in section Z, since an excellent atlas of sweep-frequency 
 backscatter data calibrated in amplitude has been compiled by 
 Gilliland (1965). 
 
 A listing of available sweep -frequency backscatter data obtained 
 at the Eric, Colorado^site is included in the appendix of this atlas 
 following the listing of range-a/.imuth and range- elevation scan back- 
 scatter data. 
 
 63 
 
The two records en page 86 of this section show examples of 
 simultaneous oblique sweep -frequency backscatter, forward pulse 
 propagation, and vertical incidence sounding data. The HF propagation 
 path was from Sterling, Virginia to Boulder, Colorado (2370 km) and 
 the experiment was described in detail by Silberstein (1958). Page 120 
 in the appendix lists the 35-mm film data on hand at Boulder from 
 this experiment. 
 
 64 
 
SWEEP-FREQUENCY DATA FORMAT 
 
 4000- 
 
 c 
 
 ^ 1000 
 
 85177 
 
 Frequency ( MHz) 
 
 Location - Boulder, Colorodo 
 
 Time - Mountain Standard Time (MST) 
 
 Output Power a; 50 kw 
 
 Pulse Repetition Frequency = 12.5 Pulses/Second 
 
 Pulse Length = 250 /xsec 
 
 j RHA 
 
 b.) Rotatabie Log-Periodic — LPA 
 
 Antennas: a.) Rtiombic Directed Toward 1 14 
 
 Geograptiic Azimutti 
 
 65 
 
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 81 
 
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 82 
 
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 85161 
 
 83 
 
NARROW-BEAM SWEEP- FREQUENCY BACKSCATTER 
 BOULDER, COLORADO - MARCH 1969 
 
 9 10 12 
 
 14 16 18 20 22 24 
 
 Frequency (MHz) 
 
 26 28 
 
 85157 
 
 84 
 
WIDE- beam/narrow -BEAM SWEEP-FREQUENCY BACKSCATTER 
 
 BOULDER, COLORADO MARCH 1969 
 Narrow-Beam Wide Beam 
 
 I I I I I I I { I I I I I I I { I I I 
 7 9 II 15 15 17 19 21 2i 25 
 
 Frequency (MHz) 
 
 25 
 
 85158 
 
 Wide Beam 
 
 
 siiiill 
 
 Narrow Beam 
 
 Wide Beam 
 
 Narrow Beam 
 
 [ , g , I * !■'■ 
 
 iiiSiiiiiill 
 
 m 
 
 MnHIII 
 
 85 
 
Simultaneous Vertical - Incidence, 
 
 Oblique - Incidence Backscatter and 
 
 Forward Pulse Sounding Data 
 
 10 12 
 1344 CST March 18, 1955 
 
 24 MHz 
 
 km 
 3000- 
 
 2000- 
 
 1000- 
 
 ■ 
 
 
 
 
 * 4 1 * " 
 
 , 1 : i \ 
 
 Liil 
 
 ■1 IWPii 
 
 
 
 Ml 
 
 -.1- 
 
 r 
 
 iTirin 
 
 
 
 
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 1 
 
 
 
 6 8 10 12 14 16 18 20 
 1240 CST November 22, 1954 
 
 22 24 MHz 
 
 86 
 
6. PPI ROTATING ANTENNA, FIXED FREQUENCY BACKSCATTER 
 
 This section contains representative examples of PPI''' back- 
 scatter data obtained during winter 19 52-1953 at the Central Radio 
 Propagation Laboratory (CRPL.) , Sterling, Virginia, field site. The 
 PPI data format is shown (<n th(! folh^wing page, along with the important 
 equipment parameters. Because of the multiplicity of different echo 
 types shown on pages 89 thrcmgh 10 i, no atten^pt has been made to 
 classify the "signatures." A listing of the available data is included 
 in the appendix following the sweep-frequency data listing. 
 
 Now the Institute for Telecommunication Sciences, ESSA. 
 7 
 
 "Plan-position-indicator" - a term evolved from military radar system 
 
 usage. 
 
 87 
 
PPI DATA FORMAT 
 
 North 
 
 West 
 
 Time Delay 
 in Milliseconds 
 
 East 
 
 Jan. 2,7:10 PM, 1953 
 Eastern Standord Time 
 
 f=l3.7 MHz 
 
 Pq^ 200 kw 
 
 Pulse Length = 60 /i. sec. 
 
 PRF = 25 Pulses/sec. 
 
 Antenno - Rototing Yagi,~7 dB Gain 
 
 Locotion - Sferling, Virginia 
 
 83571 
 
 88 
 
1650 EST 4 Dec. 1952 
 
 0405 EST 5 Dec. 1952 
 
 83556 
 
 89 
 
1004 EST 5 Dec. 1952 
 
 0158 EST 6 Dec. 1952 
 
 83557 
 
 90 
 
1209 EST 6 Dec. 1952 
 
 1647 EST 6 Dec. 1952 
 
 83558 
 
 91 
 
1655 EST 6 Dec. 1952 
 
 1713 EST 6 Dec. 1952 
 
 83559 
 
 92 
 
1731 EST 6 Dec. 1952 
 
 1009 EST 20 Dec. 1952 
 
 83560 
 
 93 
 
1249 EST 20 Dec. 1952 
 
 1503 EST 20 Dec. 1952 
 
 83561 
 
 94 
 
1637 EST 20 Dec. 1952 
 
 759 EST 20 Dec. 1952 
 
 83562 
 
 95 
 
2040 EST 21 Dec. 1952 
 
 2259 EST 21 Dec. 1952 
 
 83563 
 
 96 
 
/ / 
 
 / i 
 
 ' y. 
 
 
 > 
 
 
 0402 EST 28 Dec. 1952 
 
 1531 EST 28 Dec. 1952 
 
 83564 
 
 97 
 
0523 EST 1 Jan. 1953 
 
 1522 EST 1 Jan. 1953 
 
 83565 
 
 98 
 
1741 EST 1 Jan. 1953 
 
 1854 EST 1 Jan. 1953 
 
 83566 
 
 99 
 
1952 EST I Jan. 1953 
 
 0122 EST 2 Jan. 1953 
 
 83567 
 
 100 
 
1^27 EST 5 Jan. I'Jbi 
 
 1 628 LSI .^ Jon I Obi 
 
 83568 
 
 101 
 
1355 EST 22 Jan. 1953 
 
 1817 EST 22 Jan. 1953 
 
 83569 
 
 102 
 
0307 EST 23 Jan. 1953 
 
 0941 EST 24 Jan. 1953 
 
 83570 
 
 103 
 
7. ACKNOWLEDGMENTS 
 
 I would like to express my appreciation to several of my 
 colleagues at ITS for aiding and abetting me on this project. To Mr. L. 
 A. Berry, Mr. L. H. Tvcten, Mr. R. K. Salaman, Dr. W. H. Hooke 
 and Dr. T. M. Georges I ann indebted for many stimulating and 
 challenging discussions concerning the makeup of this atlas. 
 Professor 1. Ranzi of the Centro Radioelettrico Sperimcntale "G. 
 Marconi" in Rome, Itlay provided good examples of range -time back- 
 scatter data for section 4 of this alias. 
 
 Special thanks are also due to Mr. L. H. Tveten ^or making 
 available to me vast quantities of backscatter film data and providing 
 essential information needed to identify and catalog these data. My 
 thanks also go to Mr. R. G Kirby, (Director) and Dr. W. F. Utlaut 
 (Deputy Director) of ITS for their support of this project. 
 
 8. REFERENCES 
 
 Abel, W. G. , and L. C. Edwards (1951), The source of long-distance 
 backscatter, Proc. Inst. Radio Engrs, i9_, 1538-1541. 
 
 •^gy» Vaughn, Kenneth Da vies and Roger Salaman (1959), An Atlas of 
 oblique -incidence ionograms, NBS Tech. N( te 31. 
 
 Bates, H. F. (I960), The height of F -layer irregularities in the arctic 
 ionosphere, J. Gcophys. Res. 64, 1257-1264. (Also see 
 correction, J. Gcophys. Res. 65 , No. 4, 1304, b^oO.) 
 
 Bates, H. F. (1965), Some effects of dense E clouds on high latitude 
 HF backscatter observations, J. Geophys. Ros. 70 (23), 
 5895-5905. 
 
 Bates, H. F. (1966), Results of the HF forward and backscatter program 
 at College since 1963, Final Report, UAG-R-178, Geophysical 
 Institvitc, University of Alaska, College, Alaska. 
 
 105 
 
Benner, A. H. (1949), Predicting maximum usable frequency from 
 long-distance scatter, Proc. IRE, 37, No. 1, 44-47. 
 
 Blair, J. C. , L. L. Melanson and L. H. Tveten (1969), HF iono- 
 spheric radar ground -scatter map showing land-sea boiondaries 
 by a spectral -separation technique. Electronics Letters 5, 
 No. 4, 75-76. 
 
 Croft, T. A. (1965), The synthesis of sweep -frequency grovmd back- 
 
 scatter by digital computer. Tech. Rept. No. 84, Radioscience 
 Laboratory, Stanford University, Stanford, Calif. 
 
 Croft, Thomas A. (1967), The interpretation of HF sweep -frequency 
 backscatter soundings to deduce the structure of localized 
 ionospheric anomalies, Tech. Rep. No. 116, Radioscience 
 Laboratory, Stanford University, Stanford, Calif. 
 
 Dieminger, W. (1951), The scattering of radio waves, Proc. Phys. 
 Soc. (London) B, ^, 142-158. 
 
 Edwards, C. F. , and K, G. Jansky (1941), Measurements of the delay 
 and direction of arrival of echoes from nearby shortwave trans- 
 mitters, Proc. Inst. Radio Engrs. 29, 322-329. 
 
 Fitzgerrell, R. G. , L. L. Proctor and A. C. Wilson (1966), An HF 
 antenna array electronically scanned in elevation, ESSA Tech. 
 Rept. lER 11-ITSA 11. 
 
 Georges, T. M. , and Judith J. Stephenson (1969), HF radar signatures 
 of traveling ionospheric irregularities -3D ray -tracing simula- 
 tion. Radio Sci. 4, No. 8. 
 
 Gilliland, C. R. (1965), Sweep -frequency backscatter with calibrated 
 amplitude. Tech. Rept. No. 11, Radio Science Laboratory, 
 Stanford Univ. , Stanford, Calif. 
 
 Hagn, George H. , Donald L. Nielson and Frances H. Smith (1961), 
 
 Backscatter literature survey, SRI Report on Contract SD-66, 
 Stanford Research Institute, Menlo Park, Calif. 
 
 106 
 
Hartsfield, W. L.. , S. M. O s trow and R. Silberstein (1 950), Backscatter 
 observations by the Central Radio Propagation Laboratory - 
 August 1947 to March 1948, J. Res. NBS _44, 199-^14. 
 
 Hunsucker, R. D. , and H. F. Bates (1969), Survey of polar and 
 auroral region effects on HF propagation. Radio Sci. ^ , 
 No. 4, 347-365. 
 
 Hunsucker, Robert D. (1969), Remote sensing of the nnidlatitude 
 
 ionosphere with a narrow-beam high-frequency radar, Ph.D. 
 Dissertation, Univ. of Colorado. 
 
 Hunsucker, R. D. , and L. H. Tveten (1967), Large travelling- 
 ionospheric -disturbances observed at midlatitudes utilizing the 
 high-resolution hf backscatter technique, J. Atmos. Terr. 
 Phys. 29, 909-916. 
 
 Kono, Tetsuo (1950), Experimental study on scattered echoes, Nos. 1 
 and 2, Report of Ionosphere Research in Japan, 4^, No. 3, 
 127-135 and 4, I^o. 4, 189-199. 
 
 Peterson, A. M. (1951), The mechanism of F-layer propagated back- 
 scatter echoes, J. Geophys. Res. 56, 221-237. 
 
 Peterson, A. M. , R, D. Egan and D. S. Pratt (1959), The IGY three- 
 frequency backscatter sounder, Proc. IRE, 4]7, 300-314, 
 
 Ranzi, I., and P. Dominici (1963), Backscatter sounding during 
 
 ionospheric storms, The Effect of Disturbances of Solar Origin 
 on Coinmunications , Edited by G. J. Gassn-iann, AGARDograph 59, 
 143-154. 
 
 Silberstein, R. (1954), Sweep-frequency backscatter -some obser\'ations 
 and deductions, IRE Trans. Ant. Prcip. AP-2 , 56-63. 
 
 Silberstein, R. (1958), The use of sweep-frequency backscatter data for 
 determining oblique -incidence ionospheric characteristics, J. 
 Geophys. Res. 63, No. 2, 335-351. 
 
 107 
 
Thomas, J. A., and R. W. E. McNichol {i960), A highly directive 
 
 rotating array for 16 Mc/ s, Nature, 187 , 398. 
 Tveten, Lowell H. (1961), Ionospheric motions observed with high 
 
 frequency backscatter sovmders. Radio Propagation, J. Res. 
 
 NBS, 65D , No. 2, 115-127. 
 Tveten, Lowell H. , and Robert D, Hunsucker (1969), Remote sensing 
 
 of the terrestrial environment with an HF radio high -resolution 
 
 azimuth and elevation scan system, Proc. IEEE 5_7 
 
 No. 4, 487-493. 
 Villard, O. G. , Jr., and A. M. Peterson (1952), Scatter sounding: 
 
 A technique for study of the ionosphere at a distance, IRE Trans. 
 
 Ant. Prop, PGAP- 3 , 186-201. 
 Wright, J. W., and R. W. Knecht (1957), Atlas of ionograms 
 
 (unpublished report). 
 
 108 
 
APPENDIX 
 
 The tabulations on the left side of pages 1 10 through IZZ in this 
 appendix arc listings of some backscatter sounding data which are 
 available at the Boulder ESSA Research Laboratories. Sequences of 
 the temporal behavior of two of the "signatures" observed with the 
 narrow-beam azimuth and elevation scan radar are shown on the right 
 side of pages 110 through 1 iZ , The data were acquired every two 
 minutes and some idea of the irregularity motion may be obtained by 
 rapidly flipping the pages. The upper photos show the time behavior 
 of the "patch" signature^and tlic lower photos illustrate apparent 
 motion of the "bands" signature. 
 
 109 
 
Range -Azimuth and Range -Elevation 
 Scan Backscatter - 16 mm Film Data 
 
 Date 
 
 Start 
 
 End 
 
 Type 
 
 of "Signatures" 
 
 Roll #64/ 65-01 
 
 MST 
 
 
 
 
 
 1964 
 
 
 
 
 
 
 
 Oct. 16 
 
 1050 
 
 1500 
 
 MSB, 
 
 FS 
 
 
 
 19 
 
 0645 
 
 1800 
 
 MSB, 
 
 FS, 
 
 T, 
 
 P 
 
 19 
 
 1830 
 
 2400 
 
 MSB, 
 
 FS, 
 
 P 
 
 
 20 
 
 0000 
 
 0600 
 
 MSB, 
 
 P, : 
 
 FS 
 
 
 21 
 
 0600 
 
 1815 
 
 MSB, 
 
 FS, 
 
 T 
 
 
 22 
 
 0715 
 
 1730 
 
 MSB, 
 
 FS, 
 
 P, 
 
 LB, T 
 
 23 
 
 0800 
 
 1130 
 
 MSB, 
 
 FS 
 
 
 
 23 
 
 1200 
 
 1600 
 
 MSB, 
 
 FS, 
 
 B 
 
 
 Nov. 5 
 
 0830 
 
 1530 
 
 MSB, 
 
 FS 
 
 
 
 9 
 
 0715 
 
 1845 
 
 MSB, 
 
 FS, 
 
 T, 
 
 LB 
 
 11 
 
 0615 
 
 0700 
 
 MSB, 
 
 T 
 
 
 
 U 
 
 1700 
 
 1743 
 
 P 
 
 
 
 
 13 
 
 0620 
 
 0725 
 
 T, MSB, ; 
 
 FS 
 
 
 13 
 
 1700 
 
 1800 
 
 MSB, 
 
 FS 
 
 
 
 17 
 
 0612 
 
 0654 
 
 T, MSB 
 
 
 
 17 
 
 1600 
 
 1715 
 
 B 
 
 
 
 
 18 
 
 0615 
 
 0907 
 
 MSB, 
 
 FS 
 
 
 
 19 
 
 1650 
 
 1740 
 
 P 
 
 
 
 
 21 
 
 1555 
 
 1700 
 
 LB, FS 
 
 
 
 23 
 
 1130 
 
 1600 
 
 LB, MSB 
 
 
 
 Dec. 8 
 
 0930 
 
 Dec. 9 
 0347 
 
 MSB, 
 
 FS, 
 
 H 
 
 
 10 
 
 1508 
 
 1640 
 
 LB, MSB, 
 
 FS 
 
 
 11 
 
 1316 
 
 1455 
 
 MSB, 
 
 FS 
 
 
 
 14 
 
 1223 
 
 1334 
 
 MSB, 
 
 FS 
 
 
 
 15 
 
 0715 
 
 2040 
 
 MSB, 
 
 FS, 
 
 B, 
 
 H, P 
 
 15 
 
 2055 
 
 2400 
 
 P, LB 
 
 
 
 16 
 
 0000 
 
 -1600 
 
 MSB, 
 
 FS, 
 
 T 
 
 
 29 
 
 -1000 
 
 1635 
 
 MSB, 
 
 FS, 
 
 T 
 
 
 30 
 
 1000 
 
 1135 
 
 MSB, 
 
 FS 
 
 
 
 31 
 
 1010 
 
 1100 
 
 MSB, 
 
 FS, 
 
 T 
 
 
 1965 
 
 
 
 
 
 
 
 Jan. 4 
 
 0920 
 
 1320 
 
 LB, MSB, 
 
 FS 
 
 
 6 
 
 1005 
 
 1507 
 
 MSB 
 
 
 
 
 7 
 
 0805 
 
 1145 
 
 MSB, 
 
 FS, 
 
 T 
 
 
 7 
 
 1223 
 
 2200 
 
 MSB 
 
 
 
 
 82817 8 
 
 0023 
 
 1530 
 
 MSB, 
 
 FS, 
 
 T, 
 
 P 
 
 0843 
 
 1300 
 
 110 
 
Range -Azimuth and Range -Elevation 
 Scan Backscattcr - 16 mm Film Data 
 
 Date 
 
 Start 
 
 End 
 
 Type of "Signature" 
 
 Roll II 64/ 65-01 
 
 MST 
 
 
 
 1965 
 
 
 
 
 
 Jan. 11 
 
 1045 
 
 1110 
 
 MSB 
 
 
 13 
 
 1545 
 
 1615 
 
 MSB, FS 
 
 
 14 
 
 1216 - 
 
 -1300 
 
 
 
 20 
 
 0920 
 
 162 5 
 
 MSB 
 
 
 23 
 
 0830 
 
 0920 
 
 MSB 
 
 
 25 
 
 0920 
 
 1000 
 
 
 
 Feb. 11 
 
 1735 
 
 1850 
 
 MSB, FS 
 
 
 Roll No. 
 
 65-01 
 
 
 
 
 May 4 
 
 0900 
 
 1800 
 
 MSB, FS, 
 
 T 
 
 5 
 
 1830(6 
 
 )0630 
 
 MSB 
 
 
 17 
 
 1100 
 
 18 50 
 
 P, MSB, 
 
 FS, LB 
 
 7 
 
 2205 
 
 1445(1 
 
 9)P,MSB, 
 
 FS, LB, T, U 
 
 Roll No. 
 
 65-02 
 
 
 
 
 June 2 
 
 1030 
 
 2400 
 
 MSB, T, 
 
 P, LB 
 
 3 
 
 0000 
 
 1515 
 
 MSB, P, 
 
 T, FS 
 
 7 
 
 0925 
 
 1330 
 
 MSB, LB, 
 
 P 
 
 8 
 
 1125 
 
 1445 
 
 MSB, LB 
 
 
 9 
 
 1000 
 
 2400 
 
 T, MSB, 
 
 P 
 
 10 
 
 0000 
 
 1430 
 
 U, P, LB 
 
 , MSB, FS, T 
 
 21 
 
 1100 
 
 1300 
 
 MSB, FS 
 
 
 Roll No. 
 
 65-03 
 
 
 
 
 June 2 5 
 
 0905 
 
 1040 
 
 MSB, FS, 
 
 P 
 
 28 
 
 1145 
 
 2400 
 
 LB, MSB, 
 
 FS 
 
 29 
 
 0000 
 
 2400 
 
 LB, MSB, 
 
 FS 
 
 30 
 
 0000 
 
 1100 
 
 LB, MSB 
 
 
 Roll No. 
 
 65-04 
 
 
 
 
 July 1 
 
 1255 
 
 1450 
 
 LB, MSB, 
 
 FS 
 
 2 
 
 0900 
 
 1045 
 
 MSB, FS 
 
 
 6 
 
 0950 
 
 2400 
 
 LB, MSB, 
 
 T 
 
 7 
 
 0000 
 
 2400 
 
 LB, P, T 
 
 , MSB, FS 
 
 8 
 
 0000 
 
 1315 
 
 MSB, T 
 
 
 Roll No. 
 
 65-05 
 
 
 
 
 July 8 
 
 1410 
 
 1545 
 
 LB, MSB, 
 
 FS 
 
 12 
 
 0925 
 
 1010 
 
 MSB, FS 
 
 
 ..... 13 
 
 0020 
 
 0135 
 
 MSB. FS 
 
 
 0845 
 
 Li II 
 
 1302 
 
 82816 
 
 HI 
 
Range -Azimuth and Range -Elevation 
 Scan Backscatter - 16 mm Film Data 
 
 Date 
 
 Start End Type of "Signature" 
 
 Roll No. 
 
 65-05 
 
 MST 
 
 
 
 
 July 14 
 
 0900 
 
 2400 
 
 MSB, 
 
 FS, 
 
 P, T 
 
 15 
 
 0000 
 
 2400 
 
 MSB, 
 
 FS, 
 
 P, T, H 
 
 16 
 
 0000 
 
 1335 
 
 MSB, 
 
 FS, 
 
 P 
 
 Roll No. 
 
 65-06 
 
 
 
 
 
 July 19 
 
 0730 
 
 1030 
 
 MSB, 
 
 FS 
 
 
 19 
 
 1820 
 
 1944 
 
 MSB, 
 
 FS, 
 
 P 
 
 20 
 
 0850 
 
 2400 
 
 MSB, 
 
 FS, 
 
 LB, P, T 
 
 21 
 
 0000 
 
 1520 
 
 MSB, 
 
 LB, 
 
 P, T 
 
 22 
 
 0000 
 
 1520 
 
 MSB, 
 
 FS, 
 
 T 
 
 Roll No. 
 
 65-07 
 
 
 
 
 
 July 27 
 
 0905 
 
 2400 
 
 LB, MSB, 
 
 FS, T, P, U 
 
 28 
 
 0000 
 
 2400 
 
 FS, MSB, 
 
 P, T 
 
 29 
 
 0000 
 
 -1430 
 
 FS, MSB, 
 
 LB, P 
 
 0847 
 
 
 1966 
 
 
 
 
 
 
 
 Roll No. 
 
 66-01 
 
 
 
 
 
 
 Jan. 24 
 
 1110 
 
 1620 
 
 LB, 
 
 MSB, 
 
 FS 
 
 
 25 
 
 1110 
 
 1650 
 
 MSB 
 
 , FS, 
 
 B 
 
 
 26 
 
 1210 
 
 1625 
 
 MSB 
 
 , FS, 
 
 P 
 
 
 Roll No. 
 
 65-08a 
 
 
 
 
 
 
 Aug. 3 
 
 1045 
 
 2400 
 
 MSB 
 
 , FS, 
 
 T 
 
 
 4 
 
 00 00 
 
 2400 
 
 MSB 
 
 , FS, 
 
 T, 
 
 U, LB 
 
 5 
 
 0000 
 
 0400 
 
 MSB 
 
 , FS 
 
 
 
 Roll No. 
 
 65-08b 
 
 
 
 
 
 
 Aug. 10 
 
 1115 
 
 2400 
 
 MSB 
 
 , LB, 
 
 P, 
 
 FS, T 
 
 11 
 
 0000 
 
 2400 
 
 MSB 
 
 , T, 
 
 LB 
 
 
 Roll No. 
 
 66-02 
 
 
 
 
 
 
 Aug. 17 
 
 2000 
 
 2400 
 
 LB, 
 
 P 
 
 
 
 18 
 
 0000 
 
 2400 
 
 MSB 
 
 T 
 
 B, H 
 
 19 
 
 0000 
 
 2400 
 
 FS, 
 
 MSB, 
 
 T 
 
 
 20 
 
 0000 
 
 
 FS, 
 
 MSB, 
 
 T, 
 
 P 
 
 Roll No. 
 
 66-03 
 
 
 
 
 
 
 Sept. 12 
 
 1725 
 
 2400 
 
 FS, 
 
 MSB, 
 
 T 
 
 
 13 
 
 0000 
 
 2400 
 
 FS, 
 
 MSB, 
 
 T 
 
 
 14 
 
 0000 
 
 2400 
 
 FS, 
 
 MSB, 
 
 T 
 
 
 R7Rm ■*• -* 
 
 0000 
 
 2400 
 
 FS, 
 
 MSB, 
 
 T, 
 
 LB 
 
 1304 
 
 112 
 
Range -Azimuth and Range -Elevation 
 Scan Backscatter - 1 6 mm Film Data 
 
 Date 
 
 Start 
 
 P:nd 
 
 Type of "Signature" 
 
 
 Roll No. 
 
 66-03 
 
 MST 
 
 
 
 Sept. 16 
 
 0000 
 
 2400 
 
 FS, MSB, T, LB 
 
 
 17 
 
 0000 
 
 1730 
 
 
 
 Roll No. 
 
 66-04 
 
 
 
 
 Oct. 10 
 
 2015 
 
 2400 
 
 T, P, H, MSB, FS 
 
 
 11 
 
 0000 
 
 2400 
 
 LB, MSB, FS, B 
 
 
 12 
 
 0000 
 
 2400 
 
 U, LB, MSB, FS, B 
 
 
 13 
 
 0000 
 
 2400 
 
 LB, MSB, FS, B 
 
 
 14 
 
 0000 
 
 2400 
 
 U, MSB, FS, B 
 
 
 15 
 
 0000 
 
 1000 
 
 MSB, FS 
 
 
 Roll No. 
 
 66-05 
 
 
 
 
 Nov. 15 
 
 1350 
 
 1900 
 
 U, MSB, H 
 
 
 15 
 
 2030 
 
 2400 
 
 P, LB, MSB 
 
 
 16 
 
 0000 
 
 1130 
 
 U, H, P, B 
 
 
 16 
 
 1930 
 
 2400 
 
 U, H 
 
 
 17 
 
 0000 
 
 2400 
 
 FS, B, U, P 
 
 
 18 
 
 0000 
 
 1300 
 
 LB, U, P, FS 
 
 
 19 
 
 0130 
 
 1740 
 
 U, P, FS, B 
 
 
 Roll No. 
 
 66-06 
 
 
 
 
 Dec. 14 
 
 1637 
 
 2400 
 
 MSB, H, FS 
 
 
 15 
 
 0000 
 
 2400 
 
 B, P, MSB, FS 
 
 
 16 
 
 0000 
 
 2400 
 
 FS, H, MSB, FS, B, T, P 
 
 17 
 
 0000 
 
 1730 
 
 H, MSB, FS, B 
 
 
 1967 
 
 
 
 
 
 Roll No. 
 
 67-01 
 
 
 
 
 Jan. 18 
 
 1820 
 
 2400 
 
 MSB, FS, LB, B 
 
 
 19 
 
 0803 
 
 1910 
 
 H, FS 
 
 
 19 
 
 1918 
 
 2400 
 
 LB, MSB 
 
 
 20 
 
 0745 
 
 -1700 
 
 T, H, MSB, FS 
 
 
 20 
 
 1758 
 
 2400 
 
 T, H, MSB, FS 
 
 
 21 
 
 0025 
 
 0441 
 
 T, MSB, FS. H 
 
 
 21 
 
 0524 
 
 1701 
 
 T, MSB, FS, B 
 
 
 Roll No. 
 
 67-02 
 
 UT 
 
 
 
 Feb. 14 
 
 1430 
 
 2400 
 
 MSB, FS, T, B 
 
 
 15 
 
 2149 
 
 2400 
 
 MSB, FS, B 
 
 
 16 
 
 0038 
 
 2400 
 
 MSB, FS, T, B 
 
 
 82814 1'^ 
 
 0000 
 
 2400 
 
 MSB, FS, B 
 
 
 18 
 
 0000 
 
 2400 
 
 MSB, FS, B, 11 
 
 
 0849 
 
 1306 
 
 113 
 
Range -Azimuth and Range -Elevation 
 Scan Backscatter - 16 mm Film Data 
 
 Date Start 
 
 End 
 
 Type of "Signature" 
 
 
 Roll No. 67-03A 
 
 UT 
 
 
 
 Mar. 14 1538 
 
 2400 
 
 U, FS, B 
 
 0851 
 
 15 0000 
 
 2400 
 
 U, FS, B 
 
 
 16 0000 
 
 2400 
 
 U, FS, B 
 
 
 17 0000 
 
 2400 
 
 U, FS, B 
 
 
 18 0000 
 
 2400 
 
 U, FS, B, MSB 
 
 
 Roll No. 67-03B 
 
 
 
 
 Mar. 14 1420 
 
 2400 
 
 B 
 
 
 15 0000 
 
 2400 
 
 B 
 
 
 16 0000 
 
 2400 
 
 B, T 
 
 
 17 0000 
 
 2400 
 
 T, LB, B 
 
 
 18 0000 
 
 2400 
 
 B, LB 
 
 
 Roll No. 67-04 
 
 
 
 
 Apr. 11 0515 
 
 2400 
 
 MSB, T, U, FS 
 
 
 12 0000 
 
 2400 
 
 U, FS, MSB, T 
 
 
 13 0000 
 
 2400 
 
 U, FS, MSB, T, B 
 
 
 14 0000 
 
 2400 
 
 U, FS, B 
 
 
 15 0000 
 
 2400 
 
 U, FS, T, P 
 
 
 Roll No. 67-05A 
 
 
 
 
 May 9 0115 
 
 2400 
 
 B, U, MSB, FS, P 
 
 
 10 0000 
 
 2400 
 
 U, FS, H, P, T, MSB 
 
 
 11 0000 
 
 2400 
 
 MSB, LB, T, P 
 
 
 12 0000 
 
 2400 
 
 MSB, LB, FS, H, T, P 
 
 
 13 0000 
 
 2400 
 
 LB, MSB, FS, P, T 
 
 
 RoU No. 67-05B 
 
 
 
 
 May 22 2030 
 
 2240 
 
 FS, T, MSB 
 
 
 23 1530 
 
 1830 
 
 U, FS, T 
 
 
 23 2030 
 
 2130 
 
 FS, T 
 
 
 24 1520 
 
 2300 
 
 MSB, FS, T, P 
 
 1308 
 
 25 1500 
 
 2100 
 
 B, FS, P, MSB, T 
 
 
 Roll No. 67-06 
 
 
 
 
 Jime 13 0345 
 
 2400 
 
 LB, MSB, FS, P, B 
 
 
 14 0000 
 
 2400 
 
 U, FS, MSB, P, H 
 
 
 15 0000 
 
 2400 
 
 P, H, T, MSB, LB 
 
 
 16 0000 
 
 2400 
 
 U, MSB, P, FS 
 
 
 17 0000 
 
 2400 
 
 P, MSB, P, FS 
 
 
 m „ «tm .-. 
 
 ■f 
 
 m^ 
 
 
 1 
 
 
 
 82813 
 
 114 
 
Range -Azimuth and Range -Elevation 
 Scan Backscattcr - 1 6 mm. Filnn Data 
 
 Date 
 
 Roll No. 
 
 July 18 
 19 
 20 
 21 
 22 
 
 Roll No. 
 
 Aug. 15 
 16 
 17 
 18 
 19 
 
 Roll No. 
 
 Sept. 19 
 20 
 21 
 22 
 23 
 
 Roll No. 
 
 Oct. 24 
 25 
 26 
 27 
 28 
 
 Roll No. 
 
 Nov. 14 
 15 
 16 
 17 
 18 
 
 Roll No. 
 
 Dec. 12 
 13 
 14 
 15 
 16 
 
 82812 
 
 Start End Type of "Signature" 
 
 67-07 
 0630 
 0000 
 0000 
 0000 
 0000 
 
 67-08 
 0020 
 0000 
 0000 
 0000 
 0000 
 
 67-09 
 0000 
 0000 
 0000 
 0000 
 0000 
 
 67-10 
 1500 
 0000 
 0000 
 0000 
 0000 
 
 67-11 
 0130 
 0000 
 0000 
 0000 
 0000 
 
 67-12 
 1030 
 0000 
 0000 
 0000 
 0000 
 
 0853 
 
 UT 
 
 2400 MSB, T, P, FS 
 
 2400 MSB, P, FS 
 
 2400 MSB, FS, P, H, T 
 
 2400 MSB, FS, P 
 
 1030 MSB, FS, LB 
 
 2400 MSB, FS, T, P, B 
 
 2400 P, T, MSB, FS, B 
 
 2400 MSB, FS, LB, T 
 
 2400 MSB, FS, T 
 
 2400 MSB, FS, P, H 
 
 2400 U, FS, MSB, B, P, T 
 
 2400 MSB, LB, FS, T 
 
 2400 U, FS, P, B, LB, H, T, MSB 
 
 2400 U, FS, P, MSB 
 
 2400 LB, FS, MSB, B, U 
 
 2400 U, MSB 
 
 2400 U, FS, MSB, P 
 
 2400 U, FS, MSB 
 
 2400 U, FS, B 
 
 2400 U, FS, MSB 
 
 2400 B 
 
 2400 U, FS 
 
 2400 U, FS, MSB 
 
 2400 U, FS, MSB 1310 
 
 2400 
 
 2400 U, FS, MSB, B 
 
 2400 B, U, MSB, B 
 
 2400 MSB, FS, B 
 
 2400 MSB, T, U, FS 
 
 2400 U, MSB, FS, B 
 
 
 
 M 
 
 115 
 
Range -Azimuth and Range -Elevation 
 Scan Backscatter - 16 mm Film Data 
 
 Date Start End Type of "Signature" 
 
 FS, MSB, P, T, U, B 
 MSB, FS, T, B 
 MSB, FS, B 
 MSB, LB, FS, B 
 MSB, LB, FS, T 
 
 MSB, FS 
 
 MSB, FS, LB, B, T 
 T, MSB, FS, B 
 T, FS, MSB, P, B 
 P, MSB, FS, B, LB 
 
 MSB, FS, T, LB 
 
 MSB, FS, B, T 
 
 MSB, FS, T, LB 
 
 MSB, FS, T, LB 
 
 MSB, FS, T, U 
 
 U, FS, T, MSB 
 U, FS, MSB, P 
 U, FS, T 
 MSB, FS, U, P 
 MSB, FS, LB, P 
 
 T, FS, P 
 
 LB, P, MSB, T 
 
 P, FS, MSB 
 
 P, LB, T, MSB, U, B 
 
 U, MSB, FS, P, T 
 
 MSB, FS, H, T, P 
 
 MSB, FS, T, P, H 
 
 MSB, FS, P 
 
 MSB, P, T, B 
 
 Roll No. 
 
 68-01 
 
 UT 
 
 Jan. 1 6 
 
 0445 
 
 2400 
 
 17 
 
 0000 
 
 2400 
 
 18 
 
 0000 
 
 2400 
 
 19 
 
 0000 
 
 2400 
 
 20 
 
 0000 
 
 2400 
 
 Roll No. 
 
 68-02 
 
 
 Feb. 20 
 
 0100 
 
 2400 
 
 21 
 
 0000 
 
 2400 
 
 22 
 
 0000 
 
 1800 
 
 23 
 
 0007 
 
 2400 
 
 24 
 
 0000 
 
 2400 
 
 Roll No. 
 
 68-03 
 
 
 Mar. 12 
 
 0325 
 
 2400 
 
 13 
 
 0000 
 
 2400 
 
 14 
 
 0000 
 
 2400 
 
 15 
 
 0000 
 
 2400 
 
 16 
 
 0000 
 
 2400 
 
 Roll No. 
 
 68-04 
 
 
 Apr. 16 
 
 0700 
 
 2400 
 
 17 
 
 0000 
 
 2400 
 
 18 
 
 0000 
 
 2400 
 
 19 
 
 0000 
 
 2400 
 
 20 
 
 0000 
 
 2400 
 
 Roll No. 
 
 68-05 
 
 
 May 14 
 
 0535 
 
 
 15 
 
 0000 
 
 2400 
 
 16 
 
 0000 
 
 2400 
 
 17 
 
 0000 
 
 2400 
 
 18 
 
 0000 
 
 2400 
 
 RoU No. 
 
 68-06 
 
 
 J\m.e 12 
 
 0000 
 
 2400 
 
 13 
 
 0000 
 
 2400 
 
 14 
 
 0000 
 
 2400 
 
 15 
 
 0000 
 
 2400 
 
 MM ittMW 
 
 1312 
 
 ti. 
 
 82811 
 
 116 
 
Year 
 
 Sweep-Frequency Backscatter 
 16 mm. Film Data 
 
 Month 
 
 Days 
 
 1954 
 
 December 
 
 lllh 
 
 1955 
 
 February 
 
 9 th 
 
 1963 
 
 January 
 
 2-10 
 
 1963 
 
 February 
 
 13-28 
 
 19 63 
 
 March 
 
 1- 5 
 
 1963 
 
 March 
 
 8-31 
 
 1963 
 
 April 
 
 1-30 
 
 1963 
 
 May 
 
 1-31 
 
 1963 
 
 June 
 
 4-21 
 
 0857 
 
 
 82810 
 
 1314 
 
 fc<^ V * 
 
 117 
 
PPI - Rotating Antenna, Fixed -Frequency- 
 Backs catter - 1 6 mm Film Data 
 
 Date 
 
 Start End 
 
 1952 
 Roll No. 
 Dec. 4 
 7 
 
 1 
 0900 
 
 0537 
 
 Roll No. 
 Dec. 7 
 10 
 
 2 
 0946 
 
 0822 
 
 Roll No. 
 
 Dec. 10 
 
 13 
 
 3 
 0833 
 
 0152 
 
 Roll No. 
 
 Dec. 13 
 
 15 
 
 4 
 0255 
 
 1913 
 
 Roll No. 
 
 Dec. 15 
 
 18 
 
 5 
 1922 
 
 -1200 
 
 Roll No. 
 Dec. 12 
 
 6 
 
 0744 
 
 Roll No. 
 
 Dec. 21 
 
 23 
 
 7 
 0751 
 
 2318 
 
 Roll No. 
 
 Dec. 23 
 
 26 
 
 8 
 2326 
 
 0640 
 
 Roll No. 
 
 Dec. 26 
 
 29 
 
 9 
 1923 
 
 1308 
 
 Roll No. 
 Dec. 29 
 Jan. 1, 
 1953 
 
 10 
 1313 
 
 0026 
 
 0901 '^"'»**^ 
 
 ■Mi ^Wl 
 
 1316 1^ 
 
 lb' 
 
 I***- -"^ 
 
 82809 
 
 118 
 
PPI - Rotating Antenna, Fixed-Frequency 
 Backscatter - 16 mm Film Data 
 
 Date 
 
 Start 
 
 End 
 
 1953 
 Roll No. 
 Jan. 1 
 3 
 
 1 
 0035 
 
 17 54 
 
 Roll No. 
 Jan. 3 
 6 
 
 2 
 1802 
 
 0625 
 
 Roll No. 
 Jan. 6 
 9 
 
 3 
 632 
 
 0112 
 
 Roll No. 
 Jan. 9 
 11 
 
 4 
 0941 
 
 2356 
 
 Roll No. 
 
 Jan. 12 
 19 
 22 
 
 5 
 0009 
 1740 
 
 0414 
 0212 
 
 Roll No. 
 Jan. 22 
 24 
 
 6 
 0222 
 
 1745 
 
 Roll No. 
 Jan. 24 
 27 
 
 7 
 1753 
 
 1013 
 
 Roll No. 
 Jan. 27 
 30 
 
 8 
 1020 
 
 0438 
 
 Roll No. 
 Jan. 30 
 Feb. 2 
 
 9 
 0604 
 
 0055 
 
 0903 
 
 
 1318 
 
 Bf^ 
 
 ki..» ^-^ 
 
 82808 
 
 11^ 
 
Simulta-neous oblique sweep -frequency backscatter, 
 forward pulse propagation and vertical-incidence 
 sounding - 35 mm fil m data 
 
 Date 
 
 22- 
 
 -23 Sept. ] 
 
 L954 
 
 
 29 Sept. ] 
 
 L954 
 
 15, 
 
 19 Oct. : 
 
 L954 
 
 22- 
 
 -23 Nov. : 
 
 L954 
 
 
 29 Nov, 1 
 
 L954 
 
 7- 
 
 -21 Dec. ] 
 
 L954 
 
 18- 
 
 -21 Dec. ] 
 
 L954 
 
 3- 
 
 - 4 Jan. 1 
 
 L955 
 
 11- 
 
 -12 Jan. ] 
 
 L955 
 
 17- 
 
 -18 Jan. ] 
 
 L955 
 
 24- 
 
 -25 Jan. 1 
 
 L955 
 
 
 31 Jan. ] 
 
 L955 
 
 1- 
 
 - 2 Feb. 1 
 
 L955 
 
 7- 
 
 - 8 Feb. ] 
 
 L955 
 
 17- 
 
 -18 Feb. ] 
 
 L955 
 
 
 21 Feb. ] 
 
 L955 
 
 24- 
 
 -25 Feb. ] 
 
 L955 
 
 1- 
 
 - 2 Mar. 1 
 
 L955 
 
 8- 
 
 - 9 Mar. 1 
 
 L955 
 
 15- 
 
 -16 Mar. 1 
 
 L955 
 
 22- 
 
 -23 Mar. 1 
 
 L955 
 
 29- 
 
 -30 Mar. 1 
 
 L955 
 
 5- 
 
 - 6 Apr. ] 
 
 L955 
 
 12- 
 
 -13 Apr. ] 
 
 L955 
 
 19- 
 
 -20 Apr. ] 
 
 L955 
 
 26- 
 
 -27 Apr. ] 
 
 L955 
 
 
 29 Apr. ] 
 
 L955 
 
 10- 
 
 -11 May ] 
 
 L955 
 
 0905 
 
 1320 
 
 82807 
 
 120 
 
High -Re solution Range -Time Backscatter 
 Large Negative Filna Data 
 
 1953 
 
 Day 
 
 Month 
 
 2- 3 
 
 June 
 
 4- 5 
 
 August 
 
 11-13 
 
 
 13-14 
 
 '.' 
 
 20-21 
 
 
 25-26 
 
 
 26-27 
 
 
 31 Aug 
 
 . 1 Sept. 
 
 9-10 
 
 September 
 
 10-11 
 
 
 15-16 
 
 
 16-17 
 
 
 17-18 
 
 
 22-25 
 
 
 29 Sept. - 2 Oct. 
 5-13 October 
 
 21-23 
 
 II 
 
 26-29 
 
 II 
 
 2- 3 
 
 November 
 
 12-13 
 
 " 
 
 17-18 
 
 II 
 
 17-18 Decennber 
 
 Geographical Azimuth of 
 Antenna Heading 
 
 150' 
 
 040* 
 
 150. 
 
 040 
 
 040 
 
 150 
 
 040 
 
 040 
 
 040 
 150 
 150 
 040 
 150 
 150 
 
 150 
 
 150 
 150 
 150 
 
 150 
 150 
 150 
 
 150 
 
 0907 
 
 1322 
 
 82806 
 
 Ul 
 
High -Re solution Range -Time Backscatter 
 Large Negative Film Data 
 
 1954 
 
 Day 
 
 Month 
 
 20-22 
 
 January 
 
 7- 9 
 
 February 
 
 19-25 
 
 March 
 
 1- 2 
 
 April 
 
 5- 7 
 
 
 8-13 
 
 
 14-15 
 
 
 19-20 
 
 
 23-30 
 
 
 30 April - 5 May 
 
 6- 9 
 
 May 
 
 10-19 
 
 II 
 
 21-25 
 
 It 
 
 1- 2 
 
 June 
 
 3- 4 
 
 II 
 
 7- 9 
 
 It 
 
 15-17 
 
 It 
 
 22-25 
 
 It 
 
 21-22 
 
 October 
 
 Geographical Azimuth of 
 Antenna Heading 
 
 150" 
 
 0909 
 
 1324 
 
 82805 
 
 122 
 
091 
 
 Rll 
 
 1326 , 
 
 it%n 
 
 82804 
 
 123 
 
09!3 
 
 
 m-"^^ 
 
 1328 1 
 
 
 82803 
 
 124 
 
82802 
 
 0915 
 
 V 
 
 
 irr 
 
 ■» 
 
 1330 . 
 
 %t* 
 
 125 
 
0917 
 
 HiiJ 
 
 1332 
 
 82801 
 
 126 
 
82800 
 
 I 
 
 r 
 
 0919 
 
 
 r-"^ 
 
 1334 , 
 
 ^% 
 
 127 
 
092! 
 
 .., 
 
 fclMl I 
 
 
 82799 
 
 1336 
 
 * V 
 
 a^-*.*«i. «'^' 
 
 ■^t^ 
 
 128 
 
0923 
 
 l«* 
 
 1338 
 
 ^.. ^^^ 
 
 82798 
 
 129 
 
0925 F*l 
 
 ir: 
 
 * -"m 
 
 1340 
 
 n€L 
 
 /*-• 
 
 11'' 
 
 i 
 
 82797 
 
 130 
 
0927 
 
 P^'^ 
 
 I 
 I 1 
 
 mu 
 
 
 1342 
 
 82796 
 
 131 
 
0929 
 
 t%*.. ,♦ •••• 
 
 
 1344 
 
 U*. 
 
 ■u 
 
 82795 
 
 132 
 
 GPO 858-051 
 
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