1 /* Copyright 2002-2019 CS Systèmes d'Information 2 * Licensed to CS Systèmes d'Information (CS) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * CS licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.orekit.files.ccsds; 18 19 /** Keywords for CCSDS Navigation Data Messages.<p> 20 * Only these should be used.<p> 21 * The enumeration is split in 3 parts:<p> 22 * - Common NDM keywords;<p> 23 * - Orbit Data Messages (ODM) specific keywords;<p> 24 * - Tracking Data Messages (TDM) specific keywords.<p> 25 * References:<p> 26 * - <a href="https://public.ccsds.org/Pubs/502x0b2c1.pdf">CCSDS 502.0-B-2 recommended standard</a> ("Orbit Data Messages", Blue Book, Issue 2.0, November 2009).<p> 27 * - <a href="https://public.ccsds.org/Pubs/503x0b1c1.pdf">CCSDS 503.0-B-1 recommended standard</a> ("Tracking Data Message", Blue Book, Issue 1.0, November 2007). 28 * @author sports 29 * @author Maxime Journot 30 * @since 6.1 31 */ 32 public enum Keyword { 33 34 // --------------------------------------------------- 35 // Common NDM (Navigation Data Message) CCSDS keywords 36 // --------------------------------------------------- 37 38 /** Comments specific to a ODM file. */ 39 COMMENT, 40 /** CCSDS OEM format version. */ 41 CREATION_DATE, 42 /** Creating agency or operator. */ 43 ORIGINATOR, 44 /** Time system used for state vector, maneuver, and covariance data. */ 45 TIME_SYSTEM, 46 /** Epoch of state vector and optional Keplerian elements. 47 * Or epoch of a TDM observation. 48 */ 49 EPOCH, 50 /** Start of total time span covered by: <p> 51 * - Ephemerides data and covariance data;<p> 52 * - Tracking data session. 53 */ 54 START_TIME, 55 /** End of total time span covered by: <p> 56 * - Ephemerides data and covariance data;<p> 57 * - Tracking data session. 58 */ 59 STOP_TIME, 60 /** User defined parameter, where X is replaced by a variable length user specified character 61 * string. Any number of user defined parameters may be included, if necessary to provide 62 * essential information that cannot be conveyed in COMMENT statements. */ 63 USER_DEFINED_X, 64 /** Keyword used to delineate the start of a Meta-data block. */ 65 META_START, 66 /** Keyword used to delineate the end of a Meta-data block. */ 67 META_STOP, 68 69 // ------------------------------------------- 70 // Orbit Data Messages (ODM) specific keywords 71 // ------------------------------------------- 72 73 /** CCSDS OPM format version. */ 74 CCSDS_OPM_VERS, 75 /** CCSDS OMM format version. */ 76 CCSDS_OMM_VERS, 77 /** File creation date in UTC. */ 78 CCSDS_OEM_VERS, 79 /** Spacecraft name for which the orbit state is provided. */ 80 OBJECT_NAME, 81 /** Object identifier of the object for which the orbit state is provided. */ 82 OBJECT_ID, 83 /** Origin of reference frame. */ 84 CENTER_NAME, 85 /** Name of the reference frame in which the state vector and optional Keplerian element data are given. */ 86 REF_FRAME, 87 /** Epoch of reference frame, if not intrinsic to the definition of the reference frame. */ 88 REF_FRAME_EPOCH, 89 /** Mean element theory. */ 90 MEAN_ELEMENT_THEORY, 91 /** Position vector X-component. */ 92 X, 93 /** Position vector Y-component. */ 94 Y, 95 /** Position vector Z-component. */ 96 Z, 97 /** Velocity vector X-component. */ 98 X_DOT, 99 /** Velocity vector Y-component. */ 100 Y_DOT, 101 /** Velocity vector Z-component. */ 102 Z_DOT, 103 /** Orbit semi-major axis. */ 104 SEMI_MAJOR_AXIS, 105 /** Mean Motion. */ 106 MEAN_MOTION, 107 /** Orbit eccentricity. */ 108 ECCENTRICITY, 109 /** Orbit inclination. */ 110 INCLINATION, 111 /** Orbit right ascension of ascending node. */ 112 RA_OF_ASC_NODE, 113 /** Orbit argument of pericenter. */ 114 ARG_OF_PERICENTER, 115 /** Orbit true anomaly. */ 116 TRUE_ANOMALY, 117 /** Orbit mean anomaly.*/ 118 MEAN_ANOMALY, 119 /** Gravitational coefficient. */ 120 GM, 121 /** Spacecraft mass. */ 122 MASS, 123 /** Solar radiation pressure area. */ 124 SOLAR_RAD_AREA, 125 /** Solar radiation pressure coefficient. */ 126 SOLAR_RAD_COEFF, 127 /** Drag area. */ 128 DRAG_AREA, 129 /** Drag coefficient. */ 130 DRAG_COEFF, 131 /** Ephemeris type. */ 132 EPHEMERIS_TYPE, 133 /** Classification type. */ 134 CLASSIFICATION_TYPE, 135 /** NORAD catalogue number. */ 136 NORAD_CAT_ID, 137 /** Element set number of the satellite. */ 138 ELEMENT_SET_NO, 139 /** Revolution Number. */ 140 REV_AT_EPOCH, 141 /** SGP/SGP4 drag-like coefficient. */ 142 BSTAR, 143 /** First Time Derivative of the Mean Motion. */ 144 MEAN_MOTION_DOT, 145 /** Second Time Derivative of the Mean Motion. */ 146 MEAN_MOTION_DDOT, 147 /** Coordinate system for covariance matrix. Its value can either be RSW, RTN (both indicating 148 /* "Radial, Transverse, Normal") or TNW. */ 149 COV_REF_FRAME, 150 /** Covariance matrix [1, 1] element. */ 151 CX_X, 152 /** Covariance matrix [2, 1] element. */ 153 CY_X, 154 /** Covariance matrix [2, 2] element. */ 155 CY_Y, 156 /** Covariance matrix [3, 1] element. */ 157 CZ_X, 158 /** Covariance matrix [3, 2] element. */ 159 CZ_Y, 160 /** Covariance matrix [3, 3] element. */ 161 CZ_Z, 162 /** Covariance matrix [4, 1] element. */ 163 CX_DOT_X, 164 /** Covariance matrix [4, 2] element. */ 165 CX_DOT_Y, 166 /** Covariance matrix [4, 3] element. */ 167 CX_DOT_Z, 168 /** Covariance matrix [4, 4] element. */ 169 CX_DOT_X_DOT, 170 /** Covariance matrix [5, 1] element. */ 171 CY_DOT_X, 172 /** Covariance matrix [5, 2] element. */ 173 CY_DOT_Y, 174 /** Covariance matrix [5, 3] element. */ 175 CY_DOT_Z, 176 /** Covariance matrix [5, 4] element. */ 177 CY_DOT_X_DOT, 178 /** Covariance matrix [5, 5] element. */ 179 CY_DOT_Y_DOT, 180 /** Covariance matrix [6, 1] element. */ 181 CZ_DOT_X, 182 /** Covariance matrix [6, 2] element. */ 183 CZ_DOT_Y, 184 /** Covariance matrix [6, 3] element. */ 185 CZ_DOT_Z, 186 /** Covariance matrix [6, 4] element. */ 187 CZ_DOT_X_DOT, 188 /** Covariance matrix [6, 5] element. */ 189 CZ_DOT_Y_DOT, 190 /** Covariance matrix [6, 6] element. */ 191 CZ_DOT_Z_DOT, 192 /** Epoch of ignition. */ 193 MAN_EPOCH_IGNITION, 194 /** Maneuver duration (If = 0, impulsive maneuver). */ 195 MAN_DURATION, 196 /** Mass change during maneuver (value is < 0). */ 197 MAN_DELTA_MASS, 198 /** Coordinate system for velocity increment vector. Its value can either be RSW, RTN (both 199 * indicating "Radial, Transverse, Normal") or TNW. */ 200 MAN_REF_FRAME, 201 /** First component of the velocity increment. */ 202 MAN_DV_1, 203 /** Second component of the velocity increment. */ 204 MAN_DV_2, 205 /** Third component of the velocity increment. */ 206 MAN_DV_3, 207 /** This keyword must appear before the first line of the covariance matrix data. */ 208 COVARIANCE_START, 209 /** Start of useable time span covered by ephemerides data, it may be 210 * necessary to allow for proper interpolation. */ 211 USEABLE_START_TIME, 212 /** End of useable time span covered by ephemerides data, it may be 213 * necessary to allow for proper interpolation. */ 214 USEABLE_STOP_TIME, 215 /** The interpolation method to be used. */ 216 INTERPOLATION, 217 /** The interpolation degree. */ 218 INTERPOLATION_DEGREE, 219 /** This keyword must appear after the last line of the covariance matrix data. */ 220 COVARIANCE_STOP, 221 222 223 // ---------------------------------------------- 224 // Tracking Data Messages (TDM) specific keywords 225 // ---------------------------------------------- 226 227 // TDM Header section 228 // ------------------ 229 230 /** Header: TDM format version in the form of ‘x.y’, where ‘y’ shall be incremented for 231 * corrections and minor changes, and ‘x’ shall be incremented for major changes. 232 * <p>Obligatory: YES 233 */ 234 CCSDS_TDM_VERS, 235 236 // TDM meta-data section 237 // --------------------- 238 239 /** Meta-data: PARTICIPANT_n, n = {1, 2, 3, 4, 5}.<p> 240 * Participants in a tracking data sessions (spacecraft(s), ground station(s)...) 241 * <p>Obligatory: YES (at least 1) 242 */ 243 PARTICIPANT_1, 244 /** Participant 2. */ 245 PARTICIPANT_2, 246 /** Participant 3. */ 247 PARTICIPANT_3, 248 /** Participant 4. */ 249 PARTICIPANT_4, 250 /** Participant 5. */ 251 PARTICIPANT_5, 252 /** Meta-data: Tracking mode associated with data section of the segment.<p> 253 * - SEQUENTIAL: Applies only for range, Doppler, angles, and LOS ionosphere calibrations. 254 * The name implies a sequential signal path between tracking participants;<p> 255 * - SINGLE_DIFF: Applies for differenced data;<p> 256 * - In other cases, such as troposphere, weather, clocks, etc., use of the MODE keyword does not apply. 257 * <p>Obligatory: NO 258 */ 259 MODE, 260 /** Meta-data: The PATH keywords shall reflect the signal path by listing the index of each PARTICIPANT 261 * in order, separated by commas, with no inserted white space.<p> 262 * The first entry in the PATH shall be the transmit participant.<p> 263 * The non-indexed ‘PATH’ keyword shall be used if the MODE is SEQUENTIAL.<p> 264 * The indexed ‘PATH_1’ and ‘PATH_2’ keywords shall be used where the MODE is SINGLE_DIFF.<p> 265 * Examples:<p> 266 * - 1,2 = one-way;<p> 267 * - 2,1,2 = two-way;<p> 268 * - 3,2,1 = three-way;<p> 269 * - 1,2,3,4 = four-way;<p> 270 * - 1,2,3,2,1 = turn-around range with 1=primary station, 2=satellite, 3=secondary station. 271 * <p>Obligatory: NO 272 */ 273 PATH, 274 /** Path 1. */ 275 PATH_1, 276 /** Path 2. */ 277 PATH_2, 278 /** Frequency band for transmitted frequencies. 279 * <p>Obligatory: NO 280 */ 281 TRANSMIT_BAND, 282 /** Meta-data: Frequency band for received frequencies. 283 * <p>Obligatory: NO 284 */ 285 RECEIVE_BAND, 286 /** Meta-data: Turn-around ratio numerator. <p> 287 * Numerator of the turn-around ratio that is necessary to calculate the coherent downlink from the uplink frequency. 288 * <p>Obligatory: NO 289 */ 290 TURNAROUND_NUMERATOR, 291 /** Meta-data: Turn-around ratio denominator. 292 * <p>Obligatory: NO 293 */ 294 TURNAROUND_DENOMINATOR, 295 /** Meta-data: Timetag reference.<p> 296 * Provides a reference for time tags in the tracking data.<p> 297 * It indicates whether the timetag associated with the data is the transmit time or the receive time. 298 * <p>Obligatory: NO 299 */ 300 TIMETAG_REF, 301 /** Meta-data: Integration interval.<p> 302 * Provides the Doppler count time in seconds for Doppler data or for the creation 303 * of normal points. 304 * <p>Obligatory: NO 305 */ 306 INTEGRATION_INTERVAL, 307 /** Meta-data: Integration reference.<p> 308 * Used in conjunction with timetag reference and integration interval.<p> 309 * Indicates whether the timetag represents the start, middle or end of the integration interval. 310 * <p>Obligatory: NO 311 */ 312 INTEGRATION_REF, 313 314 /** Meta-data: Frequency offset.<p> 315 * A frequency in Hz that must be added to every RECEIVE_FREQ to reconstruct it. 316 * <p>Obligatory: NO 317 */ 318 FREQ_OFFSET, 319 /** Meta-data: Range mode.<p> 320 * COHERENT, CONSTANT or ONE_WAY. 321 * <p>Obligatory: NO 322 */ 323 RANGE_MODE, 324 /** Meta-data: Range modulus.<p> 325 * Modulus of the range observable in the units as specified by the RANGE_UNITS keyword. 326 * <p>Obligatory: NO 327 */ 328 RANGE_MODULUS, 329 /** Meta-data: The RANGE_UNITS keyword specifies the units for the range observable.<p> 330 * ‘km’ shall be used if the range is measured in kilometers.<p> 331 * ‘s’ shall be used if the range is measured in seconds.<p> 332 * 'RU' for "range units' 333 * <p>Obligatory: NO 334 */ 335 RANGE_UNITS, 336 /** Meta-data: The ANGLE_TYPE keyword shall indicate the type of antenna geometry represented in the angle data (ANGLE_1 and ANGLE_2 keywords).<p> 337 * The value shall be one of the following:<p> 338 * - AZEL for azimuth, elevation (local horizontal);<p> 339 * - RADEC for right ascension, declination or hour angle, declination (needs to be referenced to an inertial frame);<p> 340 * - XEYN for x-east, y-north;<p> 341 * - XSYE for x-south, y-east. 342 * <p>Obligatory: NO 343 */ 344 ANGLE_TYPE, 345 /** Reference frame in which data are given: used in combination with ANGLE_TYPE=RADEC. 346 * <p>Obligatory: NO 347 */ 348 REFERENCE_FRAME, 349 /** Meta-data: Transmit delays list (up to 5).<p> 350 * Specifies a fixed interval of time, in seconds, for the signal to travel from the transmitting 351 * electronics to the transmit point. Each item in the list corresponds to the each participants. 352 * <p>Obligatory: NO 353 */ 354 TRANSMIT_DELAY_1, 355 /** Second. */ 356 TRANSMIT_DELAY_2, 357 /** Second. */ 358 TRANSMIT_DELAY_3, 359 /** Second. */ 360 TRANSMIT_DELAY_4, 361 /** Second. */ 362 TRANSMIT_DELAY_5, 363 /** Meta-data: Receive delays list.<p> 364 * Specifies a fixed interval of time, in seconds, for the signal to travel from the tracking 365 * point to the receiving electronics. Each item in the list corresponds to the each participants. 366 * <p>Obligatory: NO 367 */ 368 RECEIVE_DELAY_1, 369 /** Second. */ 370 RECEIVE_DELAY_2, 371 /** Second. */ 372 RECEIVE_DELAY_3, 373 /** Second. */ 374 RECEIVE_DELAY_4, 375 /** Second. */ 376 RECEIVE_DELAY_5, 377 /** Meta-data: Data quality.<p> 378 * Estimate of the quality of the data: RAW, DEGRADED or VALIDATED. 379 * <p>Obligatory: NO 380 */ 381 DATA_QUALITY, 382 /** Meta-data: Correction angle 1.<p> 383 * Angle correction that has been added or should be added to the ANGLE_1 data. 384 * <p>Obligatory: NO 385 */ 386 CORRECTION_ANGLE_1, 387 /** Meta-data: Correction angle 2.<p> 388 * Angle correction that has been added or should be added to the ANGLE_2 data. 389 * <p>Obligatory: NO 390 */ 391 CORRECTION_ANGLE_2, 392 /** Meta-data: Correction Doppler.<p> 393 * Doppler correction that has been added or should be added to the DOPPLER data. 394 * <p>Obligatory: NO 395 */ 396 CORRECTION_DOPPLER, 397 /** Meta-data: Correction Range.<p> 398 * Range correction that has been added or should be added to the RANGE data. 399 * <p>Obligatory: NO 400 */ 401 CORRECTION_RANGE, 402 /** Meta-data: Correction receive.<p> 403 * Receive correction that has been added or should be added to the RECEIVE data. 404 * <p>Obligatory: NO 405 */ 406 CORRECTION_RECEIVE, 407 /** Meta-data: Correction transmit.<p> 408 * Transmit correction that has been added or should be added to the TRANSMIT data. 409 * <p>Obligatory: NO 410 */ 411 CORRECTION_TRANSMIT, 412 /** Meta-data: Correction applied ? YES/NO<p> 413 * Indicate whethers or not the values associated with the CORRECTION_* keywords have been 414 * applied to the tracking data. 415 * <p>Obligatory: NO 416 */ 417 CORRECTIONS_APPLIED, 418 419 420 // TDM Data section 421 // ---------------- 422 423 // Signal related keywords. 424 /** Data: Carrier power [dBW].<p> 425 * Strength of the radio signal transmitted by the spacecraft as received at the ground station or at another spacecraft. 426 */ 427 CARRIER_POWER, 428 /** Data: Doppler instantaneous [km/s].<p> 429 * Instantaneous range rate of the spacecraft. 430 */ 431 DOPPLER_INSTANTANEOUS, 432 /** Data: Doppler integrated [km/s].<p> 433 * Mean range rate of the spacecraft over the INTEGRATION_INTERVAL specified in the meta-data section. 434 */ 435 DOPPLER_INTEGRATED, 436 /** Data: Carrier power to noise spectral density ratio (Pc/No) [dBHz]. */ 437 PC_N0, 438 /** Data: Ranging power to noise spectral density ratio (Pr/No) [dBHz]. */ 439 PR_N0, 440 /** Data: Range value [km, s or RU]. 441 * @see #RANGE_UNITS 442 */ 443 RANGE, 444 /** Data: Received frequencies [Hz].<p> 445 * The RECEIVE_FREQ keyword shall be used to indicate that the values represent measurements of the received frequency.<p> 446 * The keyword is indexed to accommodate a scenario in which multiple downlinks are used.<p> 447 * RECEIVE_FREQ_n (n = 1, 2, 3, 4, 5) 448 */ 449 RECEIVE_FREQ_1, 450 /** Received frequency 2. */ 451 RECEIVE_FREQ_2, 452 /** Received frequency 3. */ 453 RECEIVE_FREQ_3, 454 /** Received frequency 4. */ 455 RECEIVE_FREQ_4, 456 /** Received frequency 5. */ 457 RECEIVE_FREQ_5, 458 /** Data: Received frequency [Hz].<p> 459 * Case without an index; where the frequency cannot be associated with a particular participant. 460 */ 461 RECEIVE_FREQ, 462 /** Data: Transmitted frequencies [Hz].<p> 463 * The TRANSMIT_FREQ keyword shall be used to indicate that the values represent measurements of a transmitted frequency, e.g., from an uplink operation.<p> 464 * The TRANSMIT_FREQ keyword is indexed to accommodate scenarios in which multiple transmitters are used.<p> 465 * TRANSMIT_FREQ_n (n = 1, 2, 3, 4, 5) 466 */ 467 TRANSMIT_FREQ_1, 468 /** Transmitted frequency 2. */ 469 TRANSMIT_FREQ_2, 470 /** Transmitted frequency 3. */ 471 TRANSMIT_FREQ_3, 472 /** Transmitted frequency 4. */ 473 TRANSMIT_FREQ_4, 474 /** Transmitted frequency 5. */ 475 TRANSMIT_FREQ_5, 476 /** Data: Transmitted frequencies rates [Hz/s].<p> 477 * The value associated with the TRANSMIT_FREQ_RATE_n keyword is the linear rate of 478 * change of the frequency TRANSMIT_FREQ_n starting at the timetag and continuing 479 * until the next TRANSMIT_FREQ_RATE_n timetag (or until the end of the data).<p> 480 * TRANSMIT_FREQ_RATE_n (n = 1, 2, 3, 4, 5) 481 */ 482 TRANSMIT_FREQ_RATE_1, 483 /** Transmitted frequency rate 2. */ 484 TRANSMIT_FREQ_RATE_2, 485 /** Transmitted frequency rate 3. */ 486 TRANSMIT_FREQ_RATE_3, 487 /** Transmitted frequency rate 4. */ 488 TRANSMIT_FREQ_RATE_4, 489 /** Transmitted frequency rate 5. */ 490 TRANSMIT_FREQ_RATE_5, 491 492 // VLBI/Delta-DOR Related Keywords 493 /** Data: DOR [s].<p> 494 * the DOR keyword represents the range measured via PATH_2 minus the range measured via PATH_1. 495 */ 496 DOR, 497 /** Data: VLBI delay [s].<p> 498 * The observable associated with the VLBI_DELAY keyword represents the time of signal 499 * arrival via PATH_2 minus the time of signal arrival via PATH_1. 500 */ 501 VLBI_DELAY, 502 503 // Angle Related Keywords 504 /** Data: ANGLE_1 in degrees and in [-180, +360[ [deg].<p> 505 * The value assigned to the ANGLE_1 keyword represents the azimuth, right ascension, or ‘X’ 506 * angle of the measurement, depending on the value of the ANGLE_TYPE keyword.<p> 507 * The angle measurement shall be a double precision value as follows: -180.0 ≤ ANGLE_1 < 360.0<p> 508 * Units shall be degrees.<p> 509 * See meta-data keyword ANGLE_TYPE for the definition of the angles. 510 */ 511 ANGLE_1, 512 /** Data: ANGLE_2 in degrees and in [-180, +360[ [deg].<p> 513 * The value assigned to the ANGLE_2 keyword represents the elevation, declination, or ‘Y’ 514 * angle of the measurement, depending on the value of the ANGLE_TYPE keyword.<p> 515 * The angle measurement shall be a double precision value as follows: -180.0 ≤ ANGLE_2 < 360.0.<p> 516 * Units shall be degrees.<p> 517 * See meta-data keyword ANGLE_TYPE for the definition of the angles. 518 */ 519 ANGLE_2, 520 521 // Time Related Keywords 522 /** Data: Clock bias [s].<p> 523 * The CLOCK_BIAS keyword can be used by the message recipient to adjust timetag 524 * measurements by a specified amount with respect to a common reference. 525 */ 526 CLOCK_BIAS, 527 /** Data: Clock drift [s/s].<p> 528 * The CLOCK_DRIFT keyword should be used to adjust timetag measurements by an amount that is a function of time with 529 * respect to a common reference, normally UTC (as opposed to the CLOCK_BIAS, which is meant to be a constant adjustment). 530 */ 531 CLOCK_DRIFT, 532 533 // Media Related Keywords 534 /** Data: STEC - Slant Total Electron Count [TECU]. 535 * The STEC keyword shall be used to convey the line of sight, 536 * one way charged particle delay or total electron count (TEC) at the timetag associated with a 537 * tracking measurement, which is calculated by integrating the electron density along the 538 * propagation path (electrons/m2). 539 */ 540 STEC, 541 /** Data: TROPO DRY [m].<p> 542 * Dry zenith delay through the troposphere measured at the timetag. 543 */ 544 TROPO_DRY, 545 /** Data: TROPO WET [m].<p> 546 * Wet zenith delay through the troposphere measured at the timetag. 547 */ 548 TROPO_WET, 549 550 // Meteorological Related Keywords 551 /** Data: Pressure [hPa].<p> 552 * Atmospheric pressure observable as measured at the tracking participant. 553 */ 554 PRESSURE, 555 /** Data: Relative humidity [%].<p> 556 * Relative humidity observable as measured at the tracking participant. 557 */ 558 RHUMIDITY, 559 /** Data: Temperature [K].<p> 560 * Temperature observable as measured at the tracking participant. 561 */ 562 TEMPERATURE, 563 564 // Miscellaneous KEYVALUE keywords 565 /** Keyword used to delineate the start of a Data block in Keyvalue files. */ 566 DATA_START, 567 /** Keyword used to delineate the end of a Data block in Keyvalue files.. */ 568 DATA_STOP, 569 570 // XML TDM start/end keywords 571 /** TDM first keyword. */ 572 tdm, 573 /** Header keyword. */ 574 header, 575 /** Body keyword. */ 576 body, 577 /** Segment keyword. */ 578 segment, 579 /** Meta-data keyword. */ 580 metadata, 581 /** Data keyword. */ 582 data, 583 /** Observation keyword. */ 584 observation; 585 }