+++ /dev/null
-#ifndef LEVEL2_H
-#define LEVEL2_H
-
-/* http://www.ncdc.noaa.gov/oa/radar/leveliidoc.html */
-typedef struct {
- /* 24 bytes */
- char version[4];
- char unknown0[16];
- char station[4];
-} __attribute__ ((packed)) level2_header_t;
-
-typedef struct {
- /**
- * Channel Terminal Manager:
- *
- * Archive II (the data tape) is a copy of messages or data packets
- * prepared for transmission from the RDA to the RPG. CTM information
- * is attached to a message or data packet for checking data integrity
- * during the transmission process and is of no importance to the base
- * data (omit or read past these bytes).
- */
- short ctm[6]; // ignore
-
- /**
- * Message Header:
- *
- * This information is used to identify either base data or one of
- * thirteen types of messages that may follow in bytes 28 - 2431. This
- * header includes the information indicated below:
- */
- // Message size in halfwords measure from this halfword to the end of
- // record.
- unsigned short size;
-
- // Channel ID:
- // 0 = Non-Redundant Site
- // 1 = Redundant Site Channel 1
- // 2 = Redundant Site Channel 2
- unsigned char id;
-
- // Message type, where:
- // 1 = DIGITAL RADAR DATA (This message may contain a combination of
- // either reflectivity, aliased velocity, or spectrum width)
- // 2 = RDA STATUS DATA.
- // 3 = PERFORMANCE/MAINTENANCE DATA.
- // 4 = CONSOLE MESSAGE - RDA TO RPG.
- // 5 = MAINTENANCE LOG DATA.
- // 6 = RDA CONTROL COMMANDS.
- // 7 = VOLUME COVERAGE PATTERN.
- // 8 = CLUTTER CENSOR ZONES.
- // 9 = REQUEST FOR DATA.
- // 10 = CONSOLE MESSAGE - RPG TO RDA.
- // 11 = LOOP BACK TEST - RDA TO RPG.
- // 12 = LOOP BACK TEST - RPG TO RDA.
- // 13 = CLUTTER FILTER BYPASS MAP - RDA to RPG.
- // 14 = EDITED CLUTTER FILTER BYPASS MAP - RPG to RDA.
- unsigned char type;
-
- // I.D. Sequence = 0 to 7FFF, then roll over back to 0.
- unsigned short seq;
-
- // Modified Julian date starting from 1/1/70
- unsigned short gen_date;
-
- // Generation time of messages in milliseconds of day past midnight
- // (UTC). This time may be different than time listed in halfwords
- // 15-16 defined below.
- unsigned int gen_time;
-
- // Number of message segments. Messages larger than message size
- // (halfword 7 defined above) are segmented and recorded in separate
- // data packets.
- unsigned short num_seg;
-
- // Message segment number.
- unsigned short seg;
-
- /**
- * Digital Radar Data Header:
- *
- * This information describes the date, time, azimuth, elevation, and
- * type of base data included in the radial. This header includes the
- * following information:
- */
- // Collection time for this radial in milliseconds of the day from
- // midnight (UTC).
- unsigned int coll_time;
-
- // Modified Julian date referenced from 1/1/70.
- unsigned short coll_date;
-
- // Unambiguous range (scaled: Value/10. = KM).
- unsigned short range;
-
- // Azimuth angle (coded: [Value/8.]*[180./4096.] = DEG). An azimuth of
- // "0 degrees" points to true north while "90 degrees" points east.
- // Rotation is always clockwise as viewed from above the radar.
- unsigned short angle;
-
- // Radial number within the elevation scan.
- unsigned short radial;
-
- // Radial status where:
- // 0 = START OF NEW ELEVATION.
- // 1 = INTERMEDIATE RADIAL.
- // 2 = END OF ELEVATION.
- // 3 = BEGINNING OF VOLUME SCAN.
- // 4 = END OF VOLUME SCAN.
- unsigned short rad_status;
-
- // Elevation angle (coded:[Value/8.]*[180./4096.] = DEG). An elevation
- // of "0 degree" is parallel to the pedestal base while "90 degrees" is
- // perpendicular to the pedestal base.
- unsigned short elev_angle;
-
- // RDA elevation number within the volume scan.
- unsigned short elev_num;
-
- // Range to first gate of reflectivity data (METERS). Range may be
- // negative to account for system delays in transmitter and/or receiver
- // components.
- short first_refl;
-
- // Range to first gate of Doppler data. Doppler data - velocity and
- // spectrum width (METERS). Range may be negative to account for
- // system delays in transmitter and/or receiver components.
- short first_dopp;
-
- // Reflectivity data gate size (METERS).
- unsigned short refl_size;
-
- // Doppler data gate size (METERS).
- unsigned short dopp_size;
-
- // Number of reflectivity gates.
- unsigned short num_refl_gate;
-
- // Number of velocity and/or spectrum width data gates.
- unsigned short num_dopp_gate;
-
- // Sector number within cut.
- unsigned short sector;
-
- // System gain calibration constant (dB biased).
- float gain;
-
- // Reflectivity data pointer (byte # from the start of digital radar
- // data message header). This pointer locates the beginning of
- // reflectivity data.
- unsigned short refl_ptr;
-
- // Velocity data pointer (byte # from the start of digital radar data
- // message header). This pointer locates beginning of velocity data.
- unsigned short vel_ptr;
-
- // Spectrum-width pointer (byte # from the start of digital radar data
- // message header). This pointer locates beginning of spectrum-width
- // data.
- unsigned short spec_ptr;
-
- // Doppler velocity resolution.
- // Value of: 2 = 0.5 m/s
- // 4 = 1.0
- unsigned short dopp_res;
-
- // Volume coverage pattern.
- // Value of: 11 = 16 elev. scans/ 5 mins.
- // 21 = 11 elev. scans/ 6 mins.
- // 31 = 8 elev. scans/ 10 mins.
- // 32 = 7 elev. scans/ 10 mins.
- unsigned short pattern;
-
- // Unused. Reserved for V&V Simulator.
- short vv_sim[4];
-
- // Reflectivity data pointer for Archive II playback. Archive II
- // playback pointer used exclusively by RDA.
- unsigned short refl_ptr_rda;
-
- // Velocity data pointer for Archive II playback. Archive II playback
- // pointer used exclusively by RDA.
- unsigned short vel_ptr_rda;
-
- // Spectrum-width data pointer for Archive II playback. Archive II
- // playback pointer used exclusively by RDA.
- unsigned short spec_ptr_rda;
-
- // Nyquist velocity (scaled: Value/100. = M/S).
- unsigned short nyquist;
-
- // Atmospheric attenuation factor (scaled: [Value/1000. = dB/KM]).
- unsigned short atten;
-
- // Threshold parameter for minimum difference in echo power between two
- // resolution volumes for them not to be labeled range ambiguous
- // (i.e.,overlaid) [Value/10. = Watts].
- short thresh;
-
- // Unused.
- short unused0[17];
-
- /**
- * Base Data:
- *
- * This information includes the three base data moments; reflectivity,
- * velocity and spectrum width. Depending on the collection method, up
- * to three base data moments may exist in this section of the packet.
- * (For this example, only reflectivity is present.) Base data is coded
- * and placed in a single byte and is archived in the following format:
- */
- // A bit confsued by these docs.
- // Note: Need to check size field to get correct size.
- unsigned char data[2300];
-
- // Reflectivity data (0 - 460 gates) (coded: [((Value-2)/2.)-32. =
- // dBZ], for Value of 0 or 1 see note below).
- //unsigned char refl[460];
-
- // Doppler velocity data (coded: for doppler velocity resolution of 0.5
- // M/S, [((Value-2)/2.)-63.5 = M/S]; for doppler resolution of 1.0 M/S,
- // [(Value-2)-127.] = M/S], for Value of 0 or 1 see note below), (0 -
- // 92 gates). Starting data location depends on length of the
- // reflectivity field, stop location depends on length of the velocity
- // field. Velocity data is range unambiguous out to 230 KM.
- //unsigned char vel[920];
-
- // Doppler spectrum width (coded: [((Value - 2)/2.)-63.5 = M/S], for
- // Value of 0 or 1 see note below), (0 - 920 gates). Starting data
- // location depends on length of the reflectivity and velocity fields,
- // stop location depends on length of the spectrum width field.
- // Spectrum width is range unambiguous out to 230 KM.
- //unsigned char spec[920];
-
- // Four bytes of trailer characters referred to the Frame Check
- // Sequence (FCS) follow the data. In cases where the three moments are
- // not all present or the number of gates for each moment have been
- // reduced, the record is padded out to a constant size of 1216
- // halfwords (2432 bytes) following the trailer characters.
- unsigned int fcs;
-} __attribute__ ((packed)) level2_packet_t;
-
-#endif
projects / grits / blobdiff