Record Structure for the Standard Catalog Information Exchange ============================================================== Scope ----- This document describes the format and the structure of the standard catalog record which contains all the useful information about a given SPOT scene. This record will be used for exchange of catalog information within the SPOT group as well as to the SPOT customers, regardless of the medium used. This specification is consistent with the capacity of the DALI system. It is used as a format specification for the "products from catalog". The SPOT 4 specifities have also been taken into account, so that the SPOT 4 transition should be as smooth as possible. Catalog Record Structure ------------------------ fld# Byte# fld. length Parameter name 1 1 to 21 21 Scene ID 2 22 to 22 1 Blank 3 23 to 30 8 Latitude Scene Center 4 31 to 39 9 Longitude Scene Center 5 40 to 40 1 / 6 41 to 48 8 Latitude Upper Left Corner 7 49 to 57 9 Longitude Upper Left Corner 8 58 to 58 1 / 9 59 to 66 8 Latitude Upper Right Corner 10 67 to 75 9 Longitude Upper Right Corner 11 76 to 76 1 / 12 77 to 84 8 Latitude Lower Left Corner 13 85 to 93 9 Longitude Lower Left Corner 14 94 to 94 1 / 15 95 to 102 8 Latitude Lower Right Corner 16 103 to 111 9 Longitude Lower Right Corner 17 112 to 112 1 / 18 113 to 117 5 Scene Orientation 19 118 to 118 1 Blank 20 119 to 123 5 Incidence Angle 21 124 to 124 1 Blank 22 125 to 129 5 Sun Azimuth 23 130 to 130 1 Blank 24 131 to 135 5 Sun Elevation 25 136 to 136 1 Blank 26 137 to 137 1 Number of Cloud Cover quotes 27 138 to 138 1 Blank 28 139 to 146 8 Cloud Cover quotes 29 147 to 147 1 Blank 30 148 to 148 1 Max. of Cloud Cover quotes 31 149 to 149 1 Blank 32 150 to 150 1 Average of Cloud Cover quotes 33 151 to 151 1 Blank 34 152 to 152 1 Number of Snow Cover quotes 35 153 to 153 1 Blank 36 154 to 161 8 Snow Cover quotes 37 162 to 162 1 Blank 38 163 to 163 1 Number of Scene Quality quotes 39 164 to 164 1 Blank 40 165 to 168 4 Scene Quality quotes 41 169 to 169 1 Blank 42 170 to 170 1 Aver. of Scene Quality quotes 43 171 to 171 1 Blank 44 172 to 175 4 Gains 45 176 to 176 1 Blank 46 177 to 177 1 Technological imaging flag 47 178 to 178 1 Blank 48 179 to 180 2 Mirror Step 49 181 to 181 1 Blank 50 182 to 182 1 Stereo Pair Status 51 183 to 183 1 Blank 52 184 to 184 1 Imaging Configuration 53 185 to 185 1 Blank 54 186 to 186 1 Quick Look Type 55 187 to 187 1 Blank 56 188 to 190 3 Revolution Number 57 191 to 191 1 Blank 58 192 to 192 1 Minimum Shift Allowed 59 193 to 193 1 Blank 60 194 to 194 1 Maximum Shift Allowed 61 195 to 195 1 Blank 62 196 to 205 10 Segment ID 63 206 to 206 1 Blank 64 207 to 207 1 Deletion / Modification Status 65 208 to 215 8 Reserved.Must be set to blanks 66 216 to 216 1 Archiving Station 67 217 to 217 1 CR (Carriage Return) 68 218 to 218 1 LF (Line Feed) Total 218 Catalog Field Descriptions -------------------------- (1) The field names are listed in order of appearance, giving the record number where they appear in the file, their format and their description. The presentation of numeric data and the number of decimals are illustrated in the examples given by the values between brackets. These values also give the maximum and minimum values the parameters can take. (2) The ASCII blank characters are noted with a 'b'. In the following, the conventions used to describe the rule for field encoding are those of ANSI X 3.9 - 1978 Standard for Programming Language FORTRAN. SCENE ID: Field #1 / I1,2I3.3,6I2.2,I1,A1 The scene identificator for this record, coded as follows: - SPOT satellite number [1 to 9] - GRS ID : KKK [001 to 738] JJJ [009 to 691] - date of scene center YYMMDD : YY : the last two digits of the year [86 to 99, then 00,01,02,etc ...] MM : the month number [01 to 12] DD : the day number within the month [01 to 31] - GMT time of scene center HHMMSS : HH : the hour [00 to 23] MM : the minutes within the hour [00 to 59] SS : the seconds within the minute [00 to 59] - HRV number [1 or 2] - Spectral Mode [P or M or X or I] GEOGRAPHIC COORDINATES: Fields #3,4,6,7,9,10,12,13,5,16 The geographic coordinates for the center point of the scene as well as the ones for the four corners of the scene will follow the same format : longitude and latitude are expressed in signed decimal degrees and are encoded according to the convention defined in Applicable Document [2]. LONGITUDE /F9.4 Positive sign towards the East, negative sign towards the West [-180.0000 to +179.9999] LATITUDE /F8.4 Positive sign towards the North, negative sign towards the South [-90.0000 to +90.0000] SCENE ORIENTATION : Field #18 /F5.1 Orientation angle of the scene : for conventions, see Applicable Document [1], page A-07-4. [0.0 to 360.0] INCIDENCE ANGLE : Field #20 /F5.1 Angle of incidence: for conventions, see Applicable Document [1], page A-07-4. [-90.0 to +90.0] SUN AZIMUTH : Field #22 /F5.1 Azimuth of the sun direction (positive eastward from north) expressed in degrees. [0.0 to 360.0] SUN ELEVATION : Field #24 /F5.1 Sun elevation expressed in degrees (negative elevation may happen for certain winter scenes in polar zones). [-90.0 to +90.0] NUMBER OF CLOUD COVER QUOTES : Field #26 /I1 The number of cloud cover quotes for this scene. This number may take the values: 4 if the quotation is performed by quadrant, 8 if the quotation is performed by 1/8 of scene. [4 or 8] CLOUD COVER QUOTES : Field #28 /4A1,4X or 8A1 Cloud cover value of the scene expressed: - either for each quadrant in the following order: upper left, upper right, lower left, lower right (4 values followed by 4 blanks), - or for each 1/8 of scene, in the following order: upper left row, upper right row, 2nd left row, 2nd right row, 3rd left row, 3rd right row, lower left row, lower right row (8 values). Two possible conventions: - [0] <10%, [1] 10-25%, [2] >25% - [A] no cloud, [B] 0-10%, [C] 10-25%, [D] 25-75 %, [E] >75% Irrespective of the convention, the value [*] may be assigned to a quadrant or a 1/8 of scene. This value indicates that there was not enough image lines in the block for quotation. This may occur for the first "incomplete" scene or the last "incomplete" scene of a segment. MAX. OF CLOUD COVER QUOTES : Field #30 /A1 The maximum value of the 4 or 8 quotes of field #28. [0 to 2] or [A to E] or [*]. The value [*] denotes that all the 4 or 8 cloud cover quotes are equal to [*] AVERAGE OF CLOUD COVER QUOTES : Field #32 /A1 The average of the 4 or 8 quotes of field #28, rounded to the closest integer. When the alphabetic convention is used, the letters are converted to integer (A -----> 0, B -----> 1, etc...) to compute the average, and the result is converted back into a letter. The quotes equal to [*] are not taken into account for this computation. [0 to 2] or [A to E] or [*] NUMBER OF SNOW COVER QUOTES : Field #34 /I1 The number of snow cover quotes for this scene. This number may take 3 values: 1 if there is a single quotation for the scene, 4 if the snow quotation is performed by quadrant, 8 if the snow quotation is performed by 1/8 of scene, blank if not used. [1 or 4 or 8 or b] SNOW COVER QUOTES : Field #36 /A1,7X or 4A1,4X or 8A1 One value (0 for "no snow", or 1 for "snow") per scene, or per quadrant, or per 1/8 of scene. Same sequential order as for cloud cover quotes. Equal to blank if not used. [0 or 1 or b or *] See "CLOUD COVER QUOTES" for the meaning of the value [*] NUMBER OF SCENE QUALITY QUOTES : Field #38 /I1 The number of scene quality quotes for this scene. This number may take 2 values : 1 if there is a single quote for the whole scene, 4 if the quotes are assigned per 1/4 of scene (the scene being split into 4 "horizontal" stripes). [ 1 or 4] SCENE QUALITY QUOTES : Field #40 /A1,3X or 4A1 The technical quality of the scene expressed with the following conventions: - either a single quote for the whole scene, - or 4 quotes in the following order : upper 1/4 of scene stripe, 2nd 1/4 of scene stripe, 3rd 1/4 of scene stripe, lower 1/4 of scene stripe. [E] = Excellent [G] = Good [P] = Poor [U] = Unusable [*] = There was no image lines in the stripe to evaluate the technical quality. This may occur for the first "incomplete" scene or the last "incomplete" scene of a segment. AVER. OF SCENE QUALITY QUOTES : Field #42 /A1 Either equal to the scene quality quotes when the number of scene quality quotes equals 1, or equal to the average of the 4 scene quality quotes (using same method as for average of cloud cover quotes). [E or G or P or U or *] GAINS : Field # 44 /I1,3X or 3I1,1X or 4I1 Value of the gain number for each spectral band P, XS1, XS2, XS3 or MIR. - When Panchro or B2 10m SPOT 4 : one single value (format I1, 3X), - when Multispectral : 3 values for XS1, XS2 and XS3 (format 3I1, 1X), - when SPOT 4 with MIR : 4 values for B1, B2, B3 and MIR (format 4I1). [0 to 8] (for each value) TECHNOLOGICAL IMAGING FLAG: Field #46 /A1 0 for standard imaging, 1 for special imaging done for technological purpose (the image may not match any standard criteria), blank if not used. [0 or 1 or b] MIRROR STEP : Field #48 /I2 The value of the mirror step of the HRV when imaging the scene. [3 to 93] STEREO PAIR STATUS : Field #50 /A1 Indicates if this scene belongs to a stereo pair. 1 if yes, blank if unknown. [1 or b] IMAGING CONFIGURATION: FIELD #52 /A1 D for "dual mode" (this HRV was imaging in P and XS mode at the same time - SPOT 1, 2 or 3 only), T for "twin mode" (the two HRVs were operating in twin mode), I for "independant" (the two HRVs were operating independently from each other), blank, if unknown [D or T or I or b] QUICK LOOK TYPE : Field #54 /A1 The type of the existing Quick Look: P for photographic, D for digital, V for video, N for "no quick look", blank if unknown. [P, D, V, N or b] REVOLUTION NUMBER : Field #56 /I3 Orbit number within this orbital cycle. [001 to 369] MINIMUM SHIFT ALLOWED : Field #58 /A1 Indicates the minimum value of the shift along track which can be applied to this scene for production purposes. This shift is expressed in 1/10 of a scene (i.e. 600 raw lines in Panchromatic, or 300 raw lines in Multispectral), truncated to the lowest integer. With the exception of the first and the last "incomplete" scenes of segment, this value is set to zero. The value is set to "*" if the scene cannot be used for production (number of useful lines too small in the first "incomplete" scene of a segment, or last "incomplete" scene of a segment). [0 to 9, or *] MAXIMUM SHIFT ALLOWED : Field #60 /A1 Indicates the maximum value of the shift along track which can be applied to this scene for production purposes. This shift is expressed in 1/10 of a scene (i.e. 600 raw lines in Panchromatic, or 300 raw lines in Multispectral), truncated to the lowest integer. With the exception of the first and the last "incomplete" scenes of segment, this value is set to 9. The value is set to "*" if the scene cannot be used for production (number of useful lines too small in the first "incomplete" scene of a segment, or last "incomplete" scene of a segment). [0 to 9, or *] SEGMENT ID : Field #62 /I10 The identification of the segment this scene belongs to. Blank if ID does not exist for this scene. [0000000000 to 9999999999] DELETION/MODIFICATION STATUS : Field #64 /A1 This is a control flag which is used for indicating the actions to be taken on this specific scene in case of deletion or modification of the information. This is used when it is needed to maintain the consistency between the master catalog and duplicate catalogs. This flag may take the values [b], [D] or [M]. [b]: no action to be taken, [D]: the scene does not exist any longer and its references have been deleted from the master catalog. Therefore, it has to be removed from the duplicate catalogs, [M]: the information related to the scene has been modified in the master catalog. The new information which is in this record must supersede the old information in the duplicate catalogs. [b or D or M] ARCHIVING STATION : Field #66 /A1 Station where the scene is archived, not necessarily where it was recorded. [T] = Toulouse, [K] = Kiruna, [P] = Prince Albert, [G] = Gatineau, [W] = Wichita, [b] = station name unavailable ... = may take more values as other stations become operational