========================================================================= AVIRIS Distribution Document 970710 THIS IS A NEW FORMAT FOR AVIRIS. SEND COMMENTS TO rog@gomez.jpl.nasa.gov All files are in a tar file. The following types of files should be found: PER FLIGHT LINE (i.e., occurs once per tar file/tape): *.avhdr general information about the flight line, *.brz browse image of the complete flight line, *.gain multiplication factors, radiance to 16-bit integer, *.geo geometric calibration data, *.log log information of the distribution processing, *.occ on-board calibration correction coefficients, *.post post flight line on-board calibrator data, *.pre pre flight line on-board calibrator data, *.rcc radiometric calibration coefficients, *.readme this file, *.spc spectral calibration file. PER SCENE (i.e., occurs once or several times per tar file/tape): *.drk1 first part of summed dark signal, *.drk2 second part of summed dark signal, *.eng engineering data, *.nav navigation data, *.img calibrated AVIRIS radiance (image) data, To list files (table-of-contents): tar tvf "tar file name" (on disc), tar tvf "device name" (on tape). To extract files: tar xvf "tar file name" "extract file name" (on disc), tar xvf "device name" "extract file name" (on tape). To get information about tar: man tar ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- PER FLIGHT LINE ---------------------------------------------------------------------------- *.avhdr GENERAL INFORMATION ABOUT THE FLIGHT LINE File type: ASCII. Information about the acquisition of the AVIRIS data. ---------------------------------------------------------------------------- *.brz BROWSE IMAGE OF THE AVIRIS FLIGHT LINE Contents: Four channels of AVIRIS data (channels 10, 33, 128, and 192). File type: BINARY 16-bit signed integer IEEE. Units: AVIRIS digitized numbers. Format: Band interleaved by pixel (channel, sample, line) with dimensions of (4, 614, NL), where NL = number of lines. To calculate the number of lines divide the size of the file by 4912 bytes per line. ---------------------------------------------------------------------------- *.gain MULTIPLICATION FACTORS, RADIANCE TO 16-BIT INTEGER Contents: Multiplication factors to store radiance as 16-bit integers. File type: ASCII. Units: none. Format: Two columns: - Multiplication factor, - Channel number. Use: When each spectrum is divided by the factors in this file the 16-bit integers are converted to radiance in units of (micro- watts/cm^2/nm/sr). ---------------------------------------------------------------------------- *.geo GEOMETRIC CALIBRATION DATA Contents: AVIRIS' spatial resolution on the ground. File type: ASCII. Format: Five columns: - Spatial sampling interval (pixel center to center distance on the ground, in milliradians), - Spatial response function (the FWHM (in milli- radians) of the spatial response function (assumed to be Gaussian); this is a measure of the nominal pixel size), - Spatial sampling interval uncertainty (in milli- radians), - Spatial response function uncertainty (in milli- radians), - Channel number. ---------------------------------------------------------------------------- *.log LOG INFORMATION ASSOCIATED WITH DISTRIBUTION PROCESSING Contents: Date the AVIRIS data were processed for distribution, Number of lines in the flight line, Number of scenes in the flight line, and Number of lines in the last scene. File type: ASCII. ---------------------------------------------------------------------------- *.occ ON-BOARD CALIBRATION CORRECTION COEFFICIENTS Contents: Calculated on-board calibration coefficients used in radiometric calibration of the data. File type: ASCII. Units: none. Format: Two columns: - On-board calibration correction coefficient, - Channel number. Use: This is the ratio between the on-board calibrator signal at the time of AVIRIS calibration and the on-board calibrator signal at the time of the flight line acquisition. ---------------------------------------------------------------------------- *.post POST FLIGHT LINE ON-BOARD CALIBRATOR DATA Contents: AVIRIS data measured from the on-board calibrator after the flight line. File type: BINARY 16-bit signed integer IEEE. Units: AVIRIS digitized numbers. Format: Band interleaved by pixel (channel, sample, line) with dimensions of (224, 614, 8). The 8 lines correspond to: - Dark signal one side of shutter, - Dark signal other side of shutter, - Spectral filter A one side of shutter, - Spectral filter A other side of shutter, - Spectral filter B one side of shutter, - Spectral filter B other side of shutter, - High signal one side of shutter, - High signal other side of shutter. Please note that this file may be of size 0 bytes, i.e., containing no data. This can happen when a flight line is too long to be contained in one file. Please contact the AVIRIS Data Facility should this be the case (assuming this data set is needed). ---------------------------------------------------------------------------- *.pre PRE FLIGHT LINE ON-BOARD CALIBRATOR DATA Contents: AVIRIS data measured from the on-board calibrator before the flight line. File type: BINARY 16-bit signed integer IEEE. Units: AVIRIS digitized numbers. Format: Band interleaved by pixel (channel, sample, line) with dimensions of (224, 614, 8). The 8 lines correspond to: - Dark signal one side of shutter, - Dark signal other side of shutter, - Spectral filter A one side of shutter, - Spectral filter A other side of shutter, - Spectral filter B one side of shutter, - Spectral filter B other side of shutter, - High signal one side of shutter, - High signal other side of shutter. ---------------------------------------------------------------------------- *.rcc RADIOMETRIC CALIBRATION COEFFICIENTS Contents: AVIRIS radiometric calibration coefficients and laboratory calibration uncertainty. File type: ASCII. Units: microwatts per centimeter_squared per nanometer per steradian per digitized_number. Format: Three columns: - Radiometric calibration coefficent, - Uncertainty in radiometric calibration coeff., - Channel number. ---------------------------------------------------------------------------- *.readme THIS FILE File type: ASCII. ---------------------------------------------------------------------------- *.spc SPECTRAL CALIBRATION FILE Contents: AVIRIS spectral calibration. File type: ASCII. Units: nanometers. Format: Five columns: - Wavelength center position, - Full width at half maximum for equivalent gaussian, - Uncertainty in wavelength center position, - Uncertainty in FWHM for equivalent gaussian, - Channel number. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- PER SCENE (512 AVIRIS lines of data) ---------------------------------------------------------------------------- *.drk1 FIRST PART OF SUMMED DARK SIGNAL Contents: First part of summed dark signal (most significant 12 bits). File type: BINARY 16-bit signed integer IEEE. Units: digitized numbers * 4096. Format: Band interleaved by pixel (channel, sample, line) with dimensions of (224, 1, 512). The last scene may be less than 512 lines. To calculate the number of lines divide the file size by 448 bytes per line. ---------------------------------------------------------------------------- *.drk2 SECOND PART OF SUMMED DARK SIGNAL Contents: Second part of summed dark signal (least significant 12 bits). File type: BINARY 16-bit signed integer IEEE. Units: digitized numbers. Format: Band interleaved by pixel (channel, sample, line) with dimensions of (224, 1, 512). The last scene may be less than 512 lines. To calculate the number of lines divide the file size by 448 bytes per line. ---------------------------------------------------------------------------- *.eng ENGINEERING DATA File type: BINARY 16-bit signed integer IEEE. ENGINEERING MINOR FRAME 2 FORMAT (12-BIT WORDS) WORD GROUP MEASUREMENT RANGE LSB/1 DN UNITS REFR.RATE 1 Temperature Detector 1 65 to 91 0.102 K 0.2Hz 2 Temperature Detector 2 65 to 91 0.102 K 0.2Hz 3 Temperature Detector 3 65 to 91 0.102 K 0.2Hz 4 Temperature Detector 4 65 to 91 0.102 K 0.2Hz 5 Temperature Spectrometer 1 -30 to +60 0.35 C 0.2Hz 6 Temperature Spectrometer 2 -30 to +60 0.35 C 0.2Hz 7 Temperature Spectrometer 3 -30 to +60 0.35 C 0.2Hz 8 Temperature Spectrometer 4 -30 to +60 0.35 C 0.2Hz 9 Temperature Scanner optics mount -10 to +80 0.35 C 0.2Hz 10 Temperature Scan motor -30 to +60 0.35 C 0.2Hz 11 Temperature Analog electronics pkg. -30 to +60 0.35 C 0.2Hz 12 Temperature Digital electronics pkg. -30 to +60 0.35 C 0.2Hz 13 Temperature Gnrl. purpose pwr supply -30 to +60 0.35 C 0.2Hz 14 Temperature FPA/Signal chain pwr sup.-30 to +60 0.35 C 0.2Hz 15 Temperature Timing generator pwr sup.-30 to +60 0.35 C 0.2Hz 16 Temperature VLDS scanner -30 to +60 0.35 C 0.2Hz 17 Temperature VLDS transport -30 to +60 0.35 C 0.2Hz 18 Temperature VLDS power supply -30 to +60 0.35 C 0.2Hz 19 Temperature On-board calibrator -30 to +60 0.35 C 0.2Hz 20 Voltage General purpose +5V 2.5 to 7.5 0.02 V 0.2Hz 21 Voltage General purpose +8V 4 to 11 0.027 V 0.2Hz 22 Voltage General purpose +20V 15 to 25 0.039 V 0.2Hz 23 Voltage General purpose -20V -26 to -12 0.055 V 0.2Hz 24 Voltage FPA/Signal chain +5V 2.5 to 7.5 0.02 V 0.2Hz 25 Voltage FPA/Signal chain +8V 4 to 11 0.027 V 0.2Hz 26 Voltage FPA/Signal chain +20V 15 to 25 0.039 V 0.2Hz 27 Voltage FPA/Signal chain -20V -26 to -12 0.055 V 0.2Hz 28 Voltage Timing generator +5V 2.5 to 7.5 0.02 V 0.2Hz 29 Voltage AC bus vltg 115V/400Hz 51.4 to 135 0.33 Vrms 0.2Hz 30 Voltage AC bus voltage +28V 18 to 32 0.055 V 0.2Hz 31 Spare 32 Spare 33 Spare 34 Spare 35 Spare 36 Spare 37 Spare 38 Spare 39 Spare Low rate sense TBD TBD TBD 0.2Hz 40 Spare Low rate sense TBD TBD TBD 0.2Hz 41 Spare Low rate sense TBD TBD TBD 0.2Hz 42 Spare Low rate sense TBD TBD TBD 0.2Hz 43 Spare High rate sense TBD TBD TBD 12Hz 44 Spare High rate sense TBD TBD TBD 12Hz 45 Spare High rate sense TBD TBD TBD 12Hz 46 Voltage Calibration lamp 0.000-8.192 0.002 V 12Hz 47 Current Calibration lamp 1.8000-2.2096 4.00E-04 A 12Hz 48 Scan mirror Linearity count rdng. 1 0 to 5427.2 10.6 uSec 12Hz 49 Scan mirror Linearity count rdng. 2 0 to 5427.2 10.6 uSec 12Hz 50 Scan mirror Linearity count rdng. 3 0 to 5427.2 10.6 uSec 12Hz 51 Scan mirror Linearity count rdng. 4 0 to 5427.2 10.6 uSec 12Hz 52 Scan mirror Linearity count rdng. 5 0 to 5427.2 10.6 uSec 12Hz 53 Scan mirror Linearity count rdng. 6 0 to 5427.2 10.6 uSec 12Hz 54 Scan mirror Linearity count rdng. 7 0 to 5427.2 10.6 uSec 12Hz 55 Scan mirror Linearity count rdng. 8 0 to 5427.2 10.6 uSec 12Hz 56 Scan mirror Linearity count rdng. 9 0 to 5427.2 10.6 uSec 12Hz 57 Scan mirror Linearity count rdng. 10 0 to 5427.2 10.6 uSec 12Hz 58 Scan mirror Linearity count rdng. 11 0 to 5427.2 10.6 uSec 12Hz 59 Instr. gyro Roll reading 1 -1.5 to +1.5 0.012 deg 12Hz 60 Instr. gyro Roll reading 2 -1.5 to +1.5 0.012 deg 12Hz 61 Instr. gyro Roll reading 3 -1.5 to +1.5 0.012 deg 12Hz 62 Instr. gyro Roll reading 4 -1.5 to +1.5 0.012 deg 12Hz 63 Instr. gyro Roll reading 5 -1.5 to +1.5 0.012 deg 12Hz 64 Instr. gyro Roll reading 6 -1.5 to +1.5 0.012 deg 12Hz 65 Instr. gyro Roll reading 7 -1.5 to +1.5 0.012 deg 12Hz 66 Instr. gyro Roll reading 8 -1.5 to +1.5 0.012 deg 12Hz 67 Instr. gyro Roll reading 9 -1.5 to +1.5 0.012 deg 12Hz 68 Instr. gyro Roll reading 10 -1.5 to +1.5 0.012 deg 12Hz 69 Instr. gyro Roll reading 11 -1.5 to +1.5 0.012 deg 12Hz 70 Instr. gyro Pitch reading 1 -1.5 to +1.5 0.012 deg 12Hz 71 Instr. gyro Pitch reading 2 -1.5 to +1.5 0.012 deg 12Hz 72 Instr. gyro Pitch reading 3 -1.5 to +1.5 0.012 deg 12Hz 73 Instr. gyro Pitch reading 4 -1.5 to +1.5 0.012 deg 12Hz 74 Instr. gyro Pitch reading 5 -1.5 to +1.5 0.012 deg 12Hz 75 Instr. gyro Pitch reading 6 -1.5 to +1.5 0.012 deg 12Hz 76 Instr. gyro Pitch reading 7 -1.5 to +1.5 0.012 deg 12Hz 77 Instr. gyro Pitch reading 8 -1.5 to +1.5 0.012 deg 12Hz 78 Instr. gyro Pitch reading 9 -1.5 to +1.5 0.012 deg 12Hz 79 Instr. gyro Pitch reading 10 -1.5 to +1.5 0.012 deg 12Hz 80 Instr. gyro Pitch reading 11 -1.5 to +1.5 0.012 deg 12Hz 81 Reserved -1.5 to +1.5 0.012 deg 82 Reserved -1.5 to +1.5 0.012 deg 83 Reserved -1.5 to +1.5 0.012 deg 84 Reserved -1.5 to +1.5 0.012 deg 85 Reserved -1.5 to +1.5 0.012 deg 86 Reserved -1.5 to +1.5 0.012 deg 87 Reserved -1.5 to +1.5 0.012 deg 88 Reserved -1.5 to +1.5 0.012 deg 89 Reserved -1.5 to +1.5 0.012 deg 90 Reserved -1.5 to +1.5 0.012 deg 91 Reserved -1.5 to +1.5 0.012 deg 92 Reserved TBD TBD TBD 93 Reserved TBD TBD TBD 94 Reserved TBD TBD TBD 95 Reserved TBD TBD TBD 96 Reserved TBD TBD TBD 97 Reserved TBD TBD TBD 98 Reserved TBD TBD TBD 99 Reserved TBD TBD TBD 100 Reserved TBD TBD TBD 101 Reserved TBD TBD TBD 102 Reserved TBD TBD TBD 103 Reserved TBD TBD TBD 104 Reserved TBD TBD TBD 105 Reserved TBD TBD TBD 106 Reserved TBD TBD TBD 107 Reserved TBD TBD TBD 108 Reserved TBD TBD TBD 109 Reserved TBD TBD TBD 110 Reserved TBD TBD TBD 111 Reserved TBD TBD TBD 112 Reserved TBD TBD TBD 113 Reserved TBD TBD TBD 114 Spare 115 Spare 116 Spare 117 Spare 118 Spare 119 Spare 120 Spare 121 Spare 122 Spare 123 Spare 124 Spare 125 F/W status (No. of dark sums) - 1 00 to FF (hex) 0Hz 126 F/W status Digital box 2 status 00 to FF (hex) 0Hz 127 Start of run Year 00 to 99 (BCD) 0Hz 128 Start of run Month 01 to 12 (BCD) 0Hz 129 Start of run Day 01 to 31 (BCD) 0Hz 130 Start of run Hours 00 to 23 (BCD) 0Hz 131 Start of run Minutes 00 to 59 (BCD) 0Hz 132 Start of run Seconds 00 to 59 (BCD) 0Hz 133 Scan timerMSB 94.33kHz cntr - 10.6 uSec 00 to FF (hex) 10.6 uSec 12Hz 134 Scan timerLSB 94.33kHz cntr - 10.6 uSec 00 to FF (hex) 10.6 uSec 12Hz 135 Last P.O.R. Year 00 to 99 (BCD) 0Hz 136 Last P.O.R. Month 01 to 12 (BCD) 0Hz 137 Last P.O.R. Day 01 to 31 (BCD) 0Hz 138 Last P.O.R. Hours 00 to 23 (BCD) 0Hz 139 Last P.O.R. Minutes 00 to 59 (BCD) 0Hz 140 Last P.O.R. Seconds 00 to 59 (BCD) 0Hz 141 H/W status Mechanism pos, misc status00 to FF (hex) 12Hz 142 F/W focus Foreoptics focus position 00 to FF (hex) 12Hz 143 Real-time clock Spare 12Hz 144 Real-time clock CSR 00 to FF (hex) 12Hz 145 Real-time clock Year 00 to 99 (BCD) 12Hz 146 Real-time clock Month 01 to 12 (BCD) 12Hz 147 Real-time clock Day 01 to 31 (BCD) 12Hz 148 Real-time clock Hours 00 to 23 (BCD) 12Hz 149 Real-time clock Minutes 00 to 59 (BCD) 12Hz 150 Real-time clock Seconds 00 to 59 (BCD) 12Hz 151 VLDS Spare 152 VLDS Spare 153 VLDS Main loop counter - MSB 00 to FF (hex) 12Hz 154 VLDS Main loop counter - LSB 00 to FF (hex) 12Hz 155 VLDS Post mortem buf chksumMSB 00 to FF (hex) 12Hz 156 VLDS Post mortem buf chksumLSB 00 to FF (hex) 12Hz 157 VLDS Post mortem event count 0 to A (hex) 12Hz 158 VLDS Status register 23 00 to FF (hex) 12Hz 159 VLDS Status register 22 00 to FF (hex) 12Hz 160 VLDS Status register 21 00 to FF (hex) 12Hz 161 VLDS Status register 20 00 to FF (hex) 12Hz 162 VLDS Status register 19 00 to FF (hex) 12Hz 163 VLDS Status register 18 00 to FF (hex) 12Hz 164 VLDS Status register 17 00 to FF (hex) 12Hz 165 VLDS Status register 16 00 to FF (hex) 12Hz 166 VLDS Status register 15 00 to FF (hex) 12Hz 167 VLDS Status register 14 00 to FF (hex) 12Hz 168 VLDS Status register 13 00 to FF (hex) 12Hz 169 VLDS Status register 12 00 to FF (hex) 12Hz 170 VLDS Status register 11 00 to FF (hex) 12Hz 171 VLDS Status register 10 00 to FF (hex) 12Hz 172 VLDS Status register 9 00 to FF (hex) 12Hz 173 VLDS Status register 8 00 to FF (hex) 12Hz 174 VLDS Status register 7 00 to FF (hex) 12Hz 175 VLDS Status register 6 00 to FF (hex) 12Hz 176 VLDS Status register 5 00 to FF (hex) 12Hz 177 VLDS Status register 4 00 to FF (hex) 12Hz 178 VLDS Status register 3 00 to FF (hex) 12Hz 179 VLDS Status register 2 00 to FF (hex) 12Hz 180 VLDS Status register 1 00 to FF (hex) 12Hz 181 VLDS Status register 0 00 to FF (hex) 12Hz 182 VLDS VLDS attn-0 assertion cnt 00 to FF (hex) 12Hz 183 VLDS VLDS exception halt count 00 to FF (hex) 12Hz 184 VLDS VLDS handshake status 00 to FF (hex) 12Hz 185 VLDS Last GSE req VLDS command 00 to 99 (BCD) 12Hz 186 VLDS Last VLDS command sent 00 to 99 (BCD) 12Hz 187 VLDS Req VLDS register id 00 to 99 (BCD) 12Hz 188 VLDS Req VLDS regstr contents 00 to FF (hex) 12Hz 189 VLDS VLDS error count 00 to FF (hex) 12Hz 190 VLDS VLDS error code 00 to FF (hex) 12Hz 191 VLDS VLDS interface error cnt 00 to FF (hex) 12Hz 192 VLDS VLDS interface error code 00 to FF (hex) 12Hz 193 F/W status Gyro saturation error cnt 00 to FF (hex) 12Hz 194 F/W status Gyro saturation err code 00 to FF (hex) 12Hz 195 F/W status Spare 196 F/W status Spare 197 F/W status Drvng intrpts t-o err cnt 00 to FF (hex) 12Hz 198 F/W status Drvng intrpts t-o err code00 to FF (hex) 12Hz 199 F/W status Cal buf write error count 00 to FF (hex) 12Hz 200 F/W status Cal buf write error code 00 to FF (hex) 12Hz 201 F/W status Quick DMA c-t err count 00 to FF (hex) 12Hz 202 F/W status Quick DMA c-t err code 00 to FF (hex) 12Hz 203 F/W status Quick PROM t-f chksm MSB 00 to FF (hex) 12Hz 204 F/W status Quick PROM t-f chksm LSB 00 to FF (hex) 12Hz 205 F/W status Quick RAM test bad addrMSB00 to FF (hex) 12Hz 206 F/W status Quick RAM test bad addrLSB00 to FF (hex) 12Hz 207 F/W status Anomalous intrpt err cnt 00 to FF (hex) 12Hz 208 F/W status Anomalous intrpt err code 00 to FF (hex) 12Hz 209 F/W status Time delay req error cnt 00 to FF (hex) 12Hz 210 F/W status Time delay req error code 00 to FF (hex) 12Hz 211 F/W status Shutter cntrl error count 00 to FF (hex) 12Hz 212 F/W status Shutter cntrl error code 00 to FF (hex) 12Hz 213 F/W status Cal fltr pos error count 00 to FF (hex) 12Hz 214 F/W status Cal fltr pos error code 00 to FF (hex) 12Hz 215 F/W status Focusing cntrl error cnt 00 to FF (hex) 12Hz 216 F/W status Focusing cntrl error code 00 to FF (hex) 12Hz 217 F/W status DMA controller error cnt 00 to FF (hex) 12Hz 218 F/W status DMA controller error code 00 to FF (hex) 12Hz 219 F/W status ENG data acqstn err count 00 to FF (hex) 12Hz 220 F/W status ENG data acqstn err code 00 to FF (hex) 12Hz 221 F/W status Flight data acqstn errcnt 00 to FF (hex) 12Hz 222 F/W status Flight data acqstn errcode00 to FF (hex) 12Hz 223 F/W status Fatal error count 00 to FF (hex) 12Hz 224 F/W status Fatal error status code 00 to FF (hex) 12Hz ---------------------------------------------------------------------------- *.nav NAVIGATION DATA File type: ASCII. This file can be typed to the screen. For each AVIRIS line the values below are encoded and written in this file: PARAMETER UNITS FORMAT BYTE SIZE SOURCE GPS status [G = valid/N = not] XX 2 Inserted UTC time (GMT) days:hrs:min:sec XXX:XX:XX:XX 12 GPS Latitude degrees N/S hXX.XXXXX 9 INU Longitude degrees E/W hXXX.XXXXX 10 INU True heading degrees XXX.XX 6 INU Pitch (up = +) degrees sXX.XXXX 8 INU Roll (right = +) degrees sXX.XXXX 8 INU Ground speed meters/second XXX.XX 6 INU Track angle degrees XXX.XX 6 INU Wind speed meters/second XX.X 4 INU Wind direction degrees XXX.X 5 INU Body long. accel. G sX.XXX 6 INU Body lat. accel. G sX.XXX 6 INU Body norm. accel. G sX.XXX 6 INU Track angle rate degrees/second sXX.X 5 INU Pitch rate degrees/second sXX.X 5 INU Roll rate degrees/second sXX.X 5 INU Inert. vert. spd. meters/second sXX.XX 6 INU GPS altitude meters XXXXX.X 7 GPS GPS latitude degrees N/S hXX.XXXXX 9 GPS GPS longitude degrees E/W hXXX.XXXXX 10 GPS Static pressure millibar XXXX.XXX 8 Analog Total pressure millibar XXXX.XXX 8 Analog Diff. pressure millibar XX.XXX 6 Analog Total temp. degrees C sXX.XX 6 Analog Static temp. degrees C sXX.XX 6 Derived Barometric alt. meters XXXXX.X 7 Derived Mach no. n/a X.XXX 5 Derived True air speed meters/second XXX.(XX) 4 (6) Derived [this last value is truncated from 6 to 4 bytes] ---------------------------------------------------------------------------- *.img CALIBRATED AVIRIS RADIANCE (IMAGE) DATA Contents: AVIRIS calibrated radiance multipled by the gain and stored as 16-bit integers. File type: BINARY 16-bit signed integer IEEE. Units: gain times (microwatts per centimeter_squared per nanometer per steradian). Format: Band interleaved by pixel (channel, sample, line) with dimensions (224, 614, 512). The last scene may be less than 512. To calculate the number of lines divide the file size by 275,072 bytes per line. -------------------------------------------------------------------------------- KNOWN ARTIFACTS 1) There is a slew effect in the AVIRIS detector array readout. Slew expresses itself as a slight shift in the IFOV when moving from regions of very different brightnesses.