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HomeWorld Data CentreData CatalogueData FormatsScaled Ionospheric Data Format Monday, Dec 11 2017 02:17 UT
Data Catalogue

Scaled Ionospheric Data Format

The scaled ionospheric parameter yearly data file downloaded from SWS website has files of the form:

SSSSPP.YY.gz

where:

  • SSSS = SWS Station Number, listed in following table
  • PP = URSI parameter code, listed in following table
  • YY = Year
  • gz = gzip file extension

The data format for each SWS record in a yearly file is as follows.

Character position Content
1-4 SWS Station Number
5-6 URSI Parameter Code
7-12 year, month, day (YYMMDD)
13-132 24 space-separated hourly values (QVVVD) where Q=qualifier, VVV=value, D=descriptor

The hourly values are in universal time (UT). The first hour of each record is 0000 UT.

Note: Macquarie Island data from 1950 - 1958 is in local time (LT) (157.5 EMT, or 10.5 hours ahead of 00 UT). The first hour of each record for this period is 0000 LT (midnight).

Following is a summary of SWS ionosonde stations.

SWS station number Station name Latitude Longitude Local mean time
3038Manila14.70121.10
3546Vanimo-2.70141.30150
3750Port Moresby-9.40147.10150
2451Cocos Islands-12.2096.8090
3351Darwin-12.45130.95135
4755Niue-19.07190.07
3755Townsville-19.63146.85150
3355Tennant Ck-19.65134.25135
2856Learmonth-22.25114.08120
3357Alice Springs-23.81133.90135
3859Brisbane-27.53152.92150
4260Norfolk Is-29.03167.97180
2960Watheroo-30.30115.90120
3460Woomera-30.80136.30135
2961Mundaring-31.98116.22120
3862Camden-34.05150.67150
3562Salisbury-34.70138.60135
3763Canberra-35.32149.00150
3766Hobart-42.92147.32150
4072Macquarie Is-54.50158.95150
2878Casey-66.30110.50105
1679Mawson-67.6062.8860
1979Davis-68.5877.9675

The URSI parameter codes are defined as follows.

Code Parameter Units Ref. UAG23 Definition
00foF20.1 MHz1.11Ordinary wave critical frequency of the highest stratification in the F region
01fxF20.1 MHz1.11Extraordinary wave critical frequency
02fzF20.1 MHz1.11Z-mode wave critical frequency
03M(3000)F20.011.50Maximum usable frequency at a defined distance divided by the critical frequency of that layer
04h'F2 km1.33Minimum virtual height of the ordinary wave trace for the highest stable stratification in the F region
05hpF2 km1.41Virtual height of the ordinary wave mode at the frequency given by 0.834 of foF2 (or other 7.34)
06h'Ox km1.39Virtual height of the x trace at foF2
07MUF(3000)F20.1 MHz1.5CStandard transmission curve for 3000 km
08hckm1.42Height of the maximum obtained by fitting a theoretical h'F curve for the parabola of best fit to the observed ordinary wave trace near foF2 and correcting for underlying ionisation
09qckm7.34Scale height
10foF10.1 MHz1.13Ordinary wave F1 critical frequency
11fxF10.1 MHz1.13Extraordinary wave F1 critical frequency
12not used
13M(3000)F10.011.50Maximum usable frequency at a defined distance divided by the critical frequency of that layer
14h'F1 km1.30Minimum virtual height of reflection at a point where the trace is horizontal
15not used
16h'F km1.32Minimum virtual height of the ordinary wave trace taken as a whole
17MUF(3000)F10.1 MHz1.5CStandard transmission curve for 3000 km
18not used
19not used
20foE0.01 MHz1.14Ordinary wave critical frequency of the lowest thick layer which causes a discontinuity
21not used
22foE20.01 MHz1.16Critical frequency of an occulting thick layer which sometimes appears between the normal E and F1 layers
23not used
24h'Ekm1.34Minimum virtual height of the normal E layer
25not used
26h'E2km1.36Minimum virtual height of the E2 layer
27not used
28not used
29not used
30foEs0.1 MHz1.17Highest ordinary wave frequency at which a mainly continuous Es trace is observed
31fxEs0.1 MHz1.17Highest extraordinary wave frequency at which a mainly continuous Es trace is observed
32fbEs0.1 MHz1.18Blanketing frequency of the Es layer
33ftEs0.1 MHzTop frequency Es any mode
34h'Es km1.35Minimum height of the trace used to give foEs
35not used
36type Es7.26Characterisation of the shape of the Es trace W type sporadic E was used at the Australian stations between about February and April 1982 in place of H, C, L and F types.
37not used
38not used
39not used
40foF1.50.01 MHz1.12Ordinary wave critical frequency of the intermediate stratification between F1 and F2
41not used
42fmin0.1 MHz1.19Lowest frequency at which echo traces are observed on the ionogram
43M(3000)F1.50.011.50Maximum usable frequency at a defined distance divided by the critical frequency of that layer
44h'F1.5km1.38Minimum virtual height of the ordinary wave trace between foF1 and foF1.5 (equals h'F2 7.34)
45not used
46not used
47fm20.1 MHz1.14Minimum frequency of the second order trace
48hmkm7.34Height of the maximum density of the F2 layer calculated by the Titheridge method
49fm30.1 MHz1.25Minimum frequency of the third order trace
50foI0.1 MHz1.26Top ordinary wave frequency of spread F traces
51fxI0.1 MHz1.21Top frequency of spread F traces
52fmI0.1 MHz1.23Lowest frequency of spread F traces
53M3000I0.011.50Maximum usable frequency at a defined distance divided by the critical frequency of that layer
54h'Ikm1.37Minimum slant range of the spread F traces
55not used(see note below)
56not used(see note below)
57dfs0.1 MHz1.22Frequency spread of the scatter pattern; 7.34 Frequency range of spread fxI-foF2
58not used
59not used
60fh'F20.1 MHz7.34Frequency at which h'F2 is measured
61fh'F0.1 MHz7.34Frequency at which h'F is measured
62not used
63h'mF1 km7.34Maximum virtual height in the o-mode F1 cusp
64h1km7.34True height at f1 Titheridge method
65h2km7.34True height at f2 Titheridge method
66h3km7.34True height at f3 Titheridge method
67h4km7.34True height at f4 Titheridge method
68h5km7.34True height at f5 Titheridge method
69Hkm7.34Effective scale height at hmF2 Titheridge method
70I2000e/cubic cm7.34Ionospheric electron content Faraday technique
71Ie/cubic cm7.34Total electron content to geostationary satellite
72Ixxxxe/cubic cm7.34Ionospheric electron content to height xxxx
73not used
74not used
75not used
76not used
77not used
78not used
79Te/cubic cm7.34Total sub-peak content Titheridge method
80FMINF0.01 MHzMinimum frequency of F trace (50 kHz increments)
81FMINE0.01 MHzMinimum frequency of E trace (50 kHz increments). Equals fbEs when E present
82HOMkmParabolic E region peak height
83YMkmParabolic E region semi-thickness
84QFkmAverage range spread of F trace
85QEkmAverage range spread of E trace
86FF0.01 MHzFrequency spread between fxF2 and fxI
87FE0.01 MHzAs FF but considered beyond foE
88fMUF30000.01 MHzMUF(D)/obliquity factor
89h'MUF3000kmVirtual height at fMUF

Note: SWS uses the codes 55 and 56 for scaling range spread (RS)(55) and frequency spread (FS)(56).

Qualifying Letters:

  • A - Less than. Used only when fbEs is deduced from foEs because total blanketing of higher layers is present
  • D - Greater than
  • E - Less than
  • I - Missing value has been replaced by an interpolated value
  • J - Ordinary component characteristic deduced from the extraordinary component
  • M - Interpretation of measurement questionable because ordinary and extraordinary components are not distinguishable. Used with descriptive letter which shows why components are not distinguishable
  • O - Extraordinary component characteristic deduced from the ordinary component
  • T - Value determined by a sequence of observations, the actual observation being inconsistent or doubtful
  • U - Uncertain or doubtful numerical value
  • Z - Measurement deduced from the third magneto-electronic component

Descriptive Letters:

  • A - Measurement influenced by, or impossible because of, the presence of a lower thin layer, for example, ES
  • B - Measurement influenced by, or impossible because of, absorption in the vicinity of fmin
  • C - Measurement influenced by, or impossible because of, any non-ionospheric reason
  • D - Measurement influenced by, or impossible because of, the upper limit of the normal frequency range
  • E - Measurement influenced by, or impossible because of, the lower limit of the normal frequency range
  • F - Measurement influenced by, or impossible because of, the presence of spread echoes
  • G - Measurement influenced by, or impossible because the ionisation density of the reflecting layer is too small to enable it to be made accurately
  • H - Measurement influenced by, or impossible because of, the presence of stratification
  • K - Presence of a particle E layer
  • L - Measurement influenced by, or impossible because the trace has no sufficiently definite cusp between the layers
  • M - Interpretation of measurement questionable because ordinary and extraordinary components are not distinguishable. Used when interpretation is doubtful and a qualifying letter needed for other reasons (e.g., U, D, E)
  • N - Conditions are such that the measurement cannot be interpreted.
  • O - Measurement refers to the ordinary component
  • P - Measurement influenced by, or impossible because of, the presence of polar spurs
  • Q - Measurement influenced by, or impossible because of, the presence of range spread
  • R - Measurement influenced by, or impossible because of, attenuation in the vicinity of the critical frequency
  • S - Measurement influenced by, or impossible because of, interference or atmospherics
  • T - Value determined by a sequence of observations, the actual value or observation being inconsistent or doubtful
  • V - Forked trace, which may influence the measurement
  • W - Measurement influenced by, or impossible because the echo lies outside the height range recorded
  • X - Measurement refers to the extraordinary component
  • Y - Lacuna phenomena, severe layer tilt
  • Z - Third magneto-electronic component present
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