Comments:
1. The format does not include any computed data items.
2. The format covers both the ILOC dataset, the RGO dataset, and future observations.
3. Provision is made to record corrections to the data, without losing the original data. Three
types of correction are envisaged: (1) date/time (2) star identifier, and (3) site coords.
Byte(s): (Format) Description
***********************************************
* Group 1 Time and Object (34) *
***********************************************
*** The data in this group incorporates any corrections made to the time and object.
The original data is maintained in groups 8 and 9 ***
1- 4: (I4) Year [Note: full year required - such as '2008']
5- 6: (I2) Month
7- 8: (I2) Day
9- 10: (I2) Hour
11- 12: (I2) Minute
13- 18: (F6.3) Second. Number of decimal places is given according to accuracy.
19 : (A1) Star catalogue / object type
R Zodiacal Catalogue
S SAO catalogue
X XZ80Q catalogue
A Numbered asteroid
P Planet and planet satellites
U Unidentified star
20- 25: (I6) Number in catalogue
For an Unidentified star - blank
For planets, number is formed as pmmm, where:
p = planet number
mmm = moon number. Set to 000 for occultation of planet.
eg Mercury = 1000, Jupiter = 5000, Ganymede = 5003, Titan = 6006
For asteroids: asteroid number. [Unnumbered asteroids cannot be specified]
26 : (A1) WDS double star component identifier (A - Z, a - z)
27 : (A1) Phenomena
D disappear
R reappear
B Blink. The mid-time of a blink event. Usually only occurs during a graze,
but can occur in near-graze situations. Duration is specified at
column 48.
(video) partial disappearance (always >25% of full light).
(visual) a short disappearance-reappearance - too close to separately
time.
f flash. the mid-time of a flash event. usually only occurs during a graze,
but can occur in near-graze situations. duration is specified at
column 48.
(video) partial reappearance (always <25% of full light).
(visual) a short reappearance-disappearance - too close to separately
time.
M Miss. The time when the star was adjacent the highest point on the
observed or predicted graze profile. Only used when other observers in
a graze observation have recorded D &/or R events
S Start or resume. Only used in a graze observation, to indicate periods
when the observer was obsrving.
E End or pause. Only used in a graze observation, to indicate periods when
the observer was not obsrving.
O Other [used by ILOC instead of S or E]
28 : (A1) Limb
D dark limb
B bright limb (including lunar eclipse penumbra)
U umbra of lunar eclipse
29 : (A1) Graze flag
G graze event
<> ordinary occultation
30- 33: (F4.2) Personal equation. Range 0.00 to 9.99 sec. Blank if PE not applicable.
34 : (A1) Application of Personal equation
S personal equation has been subtracted from the observed time.
A = S, but PE listed is an assumed value. [compatibility for ILOC
observations]
B = S, but the value of the PE applied is unknown. [compatibility
for RGO observations]
U personal equation has not been subtracted from the reported time.
E personal equation not relevant to the method of timing (eg video, eye-ear)
X Not known whether any PE has been applied.
***********************************************
* Group 2 ILOC observation codes (24) *
***********************************************
35 : (A1) Method of timing and recording
G Video with time insertion, times extracted by frame analysis
V Video with other time linking, times extracted by frame analysis
M Video with other time linking, times extracted by replay
S Stopwatch (visual)
T Tape recorder (visual)
E Eye and ear
P Photoelectric
K Key-tapping - including computer keyboards
X Chronograph
C Camera and clock
36 : (A1) Method of timing and recording (2)
Same definitions as for (35), plus the following. Blank if no second method was used.
A Time base corrected using adjacent observers
37 : (A1) Time source
G GPS (using 1PPS output, NOT GPS screen display)
R Radio signal (standard time signal)
N Network Time Protocol (using NTP software)
C Clock(adjusted by standard time signal)
T Telephone
M Some medium related with standard time signal
O GPS screen display, computer clock not using NTP software (poor accuracy).
38- 42: (F5.3) Accuracy of time. Range 0.000 to 9.999. Blank if no figure provided.
43 : (A1) Certainty
1 Sure
2 Possibly spurious
3 Most likely spurious
44- 46: (F3.1) Signal-to-Noise ratio (for video & photoelectric). Range 0.0 to 9.9. Blank if
not relevant, or not provided.
47 : (A1) Double star / unidentified star
<> No double star effect noted
W Preceding (west) component
E Following (east) component
N North component
S South component
B Brighter component
F Fainter component
U Unidentified star
48- 52: (F5.3) Duration of non-instantaneous event. Range 0.000 to 9.999 secs. Blank if
not relevant.
53 : (A1) Light level at event (for video & photoelectric, if event is
non-instantaneous)
<> Not specified
T 25% light level (consistent with fresnel diffraction)
F 50% light level (consistent with stellar diameter effects)
54 : (A1) Sky stability
<> Not specified
1 Good
2 Fair
3 Poor
55 : (A1) Sky transparency
<> Not specified
1 Good
2 Fair
3 Poor
56 : (A1) Remarkable circumstances
<> No remarkable circumstances
1 Gradual[not instantaneous] event
2 Dark limb visible
3 By averted vision
4 Star faint
5 Through thin cloud
6 Many clouds
7 Strong wind
8 In strong twilight
9 In daylight (sun altitude >-6 deg {civil twilight})
57- 59: (i3) temperature centigrade. range -49 to 50. blank if not provided.
***********************************************
* group 3 rgo observation codes (4) *
***********************************************
*** these codes are used for observations prior to 1981 ***
60 : (a1) accuracy
1 excellent, very good (+/- 0.1s, +/- 0.2s)
2 good, certain (+/- 0.3s, +/- 0.4s)
3 fair, satisfactory (+/- 0.5s to +/- 0.7s)
4 poor, uncertain (+/- 0.8s, +/- 0.9s)
5 very poor, very doubtful (+/- 1s)
6 star faint
7 perhaps early
8 perhaps late
9 uncertain by tens of seconds
61 : (a1) condition
<> not specified
1 clear, good conditions
2 haze, mist, thin cloud
3 cloud
4 difficult conditions
5 not instantaneous, gradual
6 dark limb visible
7 by averted vision
8 during lunar eclipse
9 obvious mistake corrected on report
62 : (a1) time adjusted; double star
2 reported time adjusted by integral number of
minutes, hours, etc, for obvious mistake
8 component of double star (observations of
components of double or compound star systems
which do not have positions in the zc or saoc
are indicated by an '8')
63 : (a1) timing method
<> not known
1 photoelectric
2 eye-and-ear
3 chronograph
4 stopwatch and time-signal
5 stopwatch and telephone time-signal
6 camera and clock
7 eye-and-ear with sidereal chronometer
8 chronograph and sidereal clock
9 tape recorder and time signal
0 not known
***********************************************
* group 4 compilation/edit codes (8) *
***********************************************
64- 73: (a10) future use
74 : (a1) observation validity
<> valid
a valid, after adjustments to the date/time.
b valid, after adjustments to the star number.
c valid, after adjustments to both the date/time and star number.
d valid, after adjustments to site coordinates.
e valid, after adjustments to site coordinates and date/time.
f valid, after adjustments to site coordinates and star number.
g valid, after adjustments to site coordinates and star number and date/time.
[note for codes d, e, f & g: adustments to site coordinates are made on
the basis of all observations made from a site, and not on an
event-by-event basis.]
s unknown site location. [used for rgo and iloc data, where there
is no site data for the specified station.]
t poor time base [for events before 1850]
u unidentified star [including star is not in the xz80q catalogue]
w invalid site location. the site location is definitely
in error (eg site located in the sea, or all
observations from the location have large residuals), and the
correct location cannot be deduced (eg obvious transposition
of digits in the reported site coordinates).
x assessed as an invalid observation. on investigation, confident the
relevant occultation and observing location has been identified,
with a conclusion that the event was not actually observed for
some reason - such as difficult conditions.
y limb-corrected residual greater than about 4". This is a flag
automatically generated to indicate the computed residual is
unsatisfactory. The exact criteria applied depends on the basis for
correcting the limb for its irregularities. Events with this flag
have not been individually investigated to determine whether there
is an error in the reported data, or whether the observation was
adversely affected by poor observing conditions (that is, is invalid).
Z Unresolved data errors. After considering the possibility
of errors in several of date + time, star, and site location,
the reported observation cannot be plausibly associated with a
relevant occultation.
75- 78: (I4) Graze identifier - year
79- 81: (I3) Graze identifier - number in year
***********************************************
* Group 5 Site location (96) *
***********************************************
*** The data in this group incorporates any corrections made to the site coordinates or
datum. The original data is maintained in group 10 ***
82 : (A1) Sign of longitude, +'ve to East
83- 85: (I3) degrees of longitude
86- 87: (I2) minutes of longitude
88- 92: (F5.2) seconds of longitude
93 : (A1) Sign of latitude, +'ve to North
94- 95: (I2) degrees of latitude
96- 97: (I2) minutes of latitude
98-102: (F5.2) seconds of latitude
103-104: (I2) Horizontal datum code
*** datum codes used with pre 1981 events (RGO data) ***
<> not known
1 geodetic, referred to one of the following major datum
blocks; 1927 North American Datum, European Datum or
Australian Geodetic Datum
2 geodetic, either referred to one of the secondary datum
blocks, such as Tokyo Datum or African Arc Datum, or are
referred to a national datum, such as the 1936 Ordnance
Survey of Great Britain
3 probably geodetic
4 probably astronomic
5 astronomical
10 Measured using GoogleEarth
*** ILOC datum codes used with post 1980 events ***
14 BRAZIL, 16 ED/ED1950/ED1979, 17 AZORES, 22 INDIAN, 26 LUZON1991
28 NZ1949, 29 NAD27/NAD1927, 30 CAPECANAWERAL, 31 WHITESANDS
33 OLDHAWAIAN, 34 ORDN1936, 35 ORDNCANARIES, 37 POTSDAM
38 PROV1956, 39 HITO1963, 40 PULKOVO, 41 SA69, 46 TOKYO/TD
63 ARCCAPE, 64 CAMPO-INCHAUSPE(ARG.), 66 AUSTRALIAN-GEODETIC/AU1966
73 HERMANNSKOGEL, 80 ETRS89, 81 AMER1885, 82 NAD83/NAD1983
84 GPS84/WG-84/WGS84, 85 JGD2000, 86 GDA94, 87 NZGD2000
88 NGRF2000, 89 KDG2000, 90 Hartebeesthoek94, 91 TWD94
105-110: (F6.1) Altitude (meters) [range -999.9 to +9999.9]
111 : (A1) Vertical datum code
M Mean Sea Level
E Ellipsoid. [for use when a GPS unit does not correct computed elevations
for the difference between the Ellipsoid and Mean Sea Level.]
112-120: (A9) ILOC Station + Telescope code
121-127: (A7) RGO station + Observer code
128-177: (A50) Closest town or landmark to site, and Country - comma separated.
***********************************************
* Group 6 Telescope details (11) *
***********************************************
178 : (A1) Type of telescope
R Refractor [including Achromatic, Apochromatic, binoculars,
and camera lenses]
N Newtonian reflector [including Dobsonian, Schmidt-Newtonian,
Maksutov-Newtonian, Jones-Bird, Schiefspiegler]
C Cassegrain, [including Schmidt-Cassegrain, Maksutov, Ritchy-Chretien, Dall-Kirkham]
O Other, including naked eye.
<> not known
179 : (A1) Mounting
E Equatorial mounting
A Alt-Azimuth mounting
<> not known
180 : (A1) Driving
D Driven
M Manual
<> not known
181-184: (I4) Telescope aperture (cm) - rounded to the nearest cm.
185-188: (I4) Telescope focal length (cm) - rounded to the nearest cm.
***********************************************
* Group 7 Observer names (25) *
***********************************************
189-213: (A25) Observer name
***********************************************
* Group 8 Original date/time (18) *
***********************************************
*** The original date and time are given in this group ***
214-217: (I4) Year
218-219: (I2) Month
220-221: (I2) Day
222-223: (I2) Hour
224-225: (I2) Minute
226-231: (F6.3) Second
***********************************************
* Group 9 Original object (7) *
***********************************************
*** The original object number is given in this group. ***
232 : (A1) Star catalogue
R Zodiacal Catalogue
S SAO catalogue
X XZ80Q catalogue
A Numbered asteroid
P Planet and planet satellites
U Unidentified star
233-238: (I6) Number in catalogue
For an Unidentified star - blank
For planets, number is formed as pmmm, where:
p = planet number
mmm = moon number. Set to 000 for occultation of planet.
eg Mercury = 1000, Jupiter = 5000, Ganymede = 5003, Titan = 6006
For asteroids: asteroid number. Unnumbered asteroids cannot be specified.
***********************************************
* Group 10 Original site coordinates [30+2] *
***********************************************
*** The original site coordinates are given in this group. ***
239 : (A1) Sign of longitude, +'ve to East
240-242: (I3) degrees of longitude
243-244: (I2) minutes of longitude
245-249: (F5.2) seconds of longitude
250 : (A1) Sign of latitude, +'ve to North
251-252: (I2) degrees of latitude
253-254: (I2) minutes of latitude
255-259: (F5.2) seconds of latitude
260-261: (I2) Horizontal datum code
*** datum codes used pre 1981 (RGO data) ***
<> not known
1 geodetic, referred to one of the following major datum
blocks; 1927 North American Datum, European Datum or
Australian Geodetic Datum
2 geodetic, either referred to one of the secondary datum
blocks, such as Tokyo Datum or African Arc Datum, or are
referred to a national datum, such as the 1936 Ordnance
Survey of Great Britain
3 probably geodetic
4 probably astronomic
5 astronomical
10 Measured using GoogleEarth
*** ILOC datum codes used post 1980 ***
14 BRAZIL, 16 ED/ED1950/ED1979, 17 AZORES, 22 INDIAN, 26 LUZON1991
28 NZ1949, 29 NAD27/NAD1927, 30 CAPECANAWERAL, 31 WHITESANDS
33 OLDHAWAIAN, 34 ORDN1936, 35 ORDNCANARIES, 37 POTSDAM
38 PROV1956, 39 HITO1963, 40 PULKOVO, 41 SA69, 46 TOKYO/TD
63 ARCCAPE, 64 CAMPO-INCHAUSPE(ARG.), 66 AUSTRALIAN-GEODETIC/AU1966
73 HERMANNSKOGEL, 80 ETRS89, 81 AMER1885, 82 NAD83/NAD1983
84 GPS84/WG-84/WGS84, 85 JGD2000, 86 GDA94, 87 NZGD2000
88 NGRF2000, 89 KDG2000, 90 Hartebeesthoek94, 91 TWD94
262-267: (F6.1) Altitude (meters) [range -999.9 to +9999.9]
268 : (A1) Vertical datum code
M Mean Sea Level
E Ellipsoid. [for use when a GPS unit does not correct computed elevations
for the difference between the Ellipsoid and Mean Sea Level.]
269-270: (A2) CR/LF sequence
NOTES
All Text fields [Ax] are left justified.
All integer fields [Ix] are right justified.
All floating point fields are aligned by the decimal point.
For floating point fields, the number of decimal places used is determined by the accuracy of the
reported data. The remainder of the field is padded with spaces, not zeros.
********************************************************************************************************
VERSION history
V 1.0 1 September 2008
Released
********************************************************************************************************
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