AOC Standard Tape FormatVersion 1.07/20/00
Download a PostScript version of this documentFORTRAN code to read and use Standard tape data
Error Analysis
AOC Standard Tape Record Types
If the word address is a negative number, the third and fourth numbers are coefficients used to compute the dynamic calibration constant for the parameter. The fifth number is the offset that was calculated from the most recent calibration flight.
The following lines of code describe the computation of the dynamic calibration constants for the parameters:
IMPORTANT NOTICE!!! Beginning with Hurricane Season 1993 the measured static and dynamic pressures will be dynamically corrected using the following equations,
where pqm is measured dyn. pressure PQCOR = -PQERR
ALTERR= -.35 + .50/(1.+(psm/410.)**(-25))
- (.15/(1.+(psm/640.)**(-12))
ALTCOR = -ALTERR
PS = PSM + PQCOR + ALTCOR, corrected static pressure
These aforementioned equations are the results from a trailing cone flight.
CONVERTED DATA VALUE = TYPE 5 DATA / DIVISOR
Green numbers represent the type 5 record word address.
PSXX = PSM(IPS) ! STORE SELECTED MEASURED STATIC PRESSURE
PQYY = PQM(IPQ) ! STORE SELECTED MEASURED DYNAMIC PRESSURE
if(iac.eq.42) then ! FOR NOAA42
if(ipq.eq.0) pqyy = pqyy - 2. !IF WING TIP DYNAMIC PRESSURE
! SELECTED USE VAG. OFFSET FROM OBSERVATIONS
if(ips.eq.1) psxx = psxx + 2. !IF WINGTIP STATIC PRESSURE
! SELECTED USE AVG. OFFSET FROM OBSERVATIONS
C..... COMPUTE STATIC PRESSURE DEFECT USING DYNAMIC PRESSURE (PQM)
PQERR = .15211*PQYY - .0122277*PQYY**2 +
+ .00185083*PQYY**2.5 - 7.7304E-05*PQYY**3
C..... CORRECT THE RESIDUAL ERROR USING ALTITUDE
C..... USE MEASURED STATIC PRESSURE (PSM) FOR ALTITUDE
ALTERR = -.17 + .17 / (1.+(PSXX/560.)**(-18))
else ! FOR NOAA43
if(ipq.eq.0) pqyy = pqyy - 3.30 !IF WINGTIP DYNAMIC PRESSURE
! SELECTED USE AVG. OFFSET FROM OBSERVATIONS
if(ips.eq.1) psxx = psxx + 3.70 !IF WINGTIP STATIC PRESSURE
! SELECTED USE AVG. OFFSET FROM OBSERVATIONS
! SELECTED USE AVG. OFFSET FROM OBSERVATIONS
C..... COMPUTE STATIC PRESSURE DEFECT USING DYNAMIC PRESSURE (PQM)
PQERR = .17701*PQYY - .0129067*PQYY*PQYY +
+ .00190547*PQYY**2.5 - 7.8284E-05*PQYY**3
C..... CORRECT THE RESIDUAL ERROR USING ALTITUDE
C..... USE MEASURED STATIC PRESSURE (PSM) FOR ALTITUDE
C
ALTERR = -.35 + .5 / (1.+(PSXX/410.)**(-25)) -
+ (.15 / (1.+(PSXX/640.)**(-12)))
end if
C---------------------------------------------------------------
ALTCOR = -ALTERR
PQCOR = -PQERR
1. PS = PSXX + PQCOR + ALTCOR ! correct static pressure
2. PQ = PQYY - PQCOR - ALTCOR ! correct dynamic pressure
3. EE-VAPOR PRESSURE (MB)
IF(DW1.GE.0)
EE=6.1078*EXP((17.6498*DW1)/(243.17+DW1))
TD=DW1
IF(DW1.LT.0)
EE=6.1078*EXP((22.4716*DW1)/(272.722+DW1))
TD=243.17*(ALOG(EE)-1.8096)/(19.4594-ALOG(EE))
4. GM-RATIO OF SPECIFIC HEATS (DIMENSIONLESS)
E=EE/(PS-EE)
AMR = .62197 * E
GM=(1004.64+1846.004*AMR) / (717.6+1384.04*AMR)
GO=GM-1.
RGAS - GAS CONSTANT CP - SPECIFIC HEAT AT CONSTANT PRESSURE
RGAS = 287.05 * (1. + 1.6078*AMR) / (1.+AMR)
CP = RGAS * GM / GO
5. MA-MACH NUMBER (DIM)
MA=SQRT((2./GO)*((1+ABS(PQ)/PS)**(GO/GM)-1.))
6. AA-ATTACK ANGLE (°)
AA=B+A*AP/DAP
7. SA-SLIP ANGLE (°)
SA=B+A*BP/DBP
C A AND B DETERMINED BY INFLIGHT CALIBRATIONS.
8. PA-PRESSURE ALTITUDE (M)
PA=44331.*(1.-(PS/1013.25)**0.190263)
9. GA-GEOPOTENTIAL ALTITUDE (M)
G = 9.80616 * (1. - cos(2.*lat) *.0026373)
DEM = 3.085462e-06 + 2.27e-09*(cos(2.*lat)) - 2.e-12*(cos(4.*lat))
R = (2. * G) / DEM
GA = (G * R * ralt) / (9.8 * (R + ralt)),
10. DV-DVALUE (M)
DV=GA-PA
11. TN-AMBIENT TEMPERATURE (° K)
TTK = TT + 273.16 ! MEASURED TOTAL TEMPERATURE
TN = TTK * (PS/(PS+PQ)) ** (GO/GM)
DEN = PS / (RGAS*TN) *100. ! DENSITY OF AIR AT FLT LEVEL
TEE = (1 / (CP*DEN)) * PQ * PQ / SQRT(PS) TEMP PROBE RECOVERY
TTK = TTK + TEE ! CORRECTED TOTAL TEMPERATURE
TN = TTK * (PS/(PS+PQ)) ** (GO/GM) ! CORRECTED AMBIENT
! TEMPERATURE
12. TAS-TRUE AIRSPEED (M/SEC)
TS= SQRT(2. * CP * (TTK-TN))
13. TV-VIRTUAL TMEPERATURE (° K)
TV= RGAS * TN / 287.05
14. TA-AMBIENT TEMPERATURE (° C)
TA=TN-273.16
15. RA - ALTITUDE (M)
ALT0=RA (OVER WATER)
ALT0=10+1.05414*PA (OVER LAND)
16. WGS-VERTICAL VELOCITY (M/SEC) WITH RESPECT TO GROUND
Integeration of accelerometer data merged with differentation of
selected radar altimeter data
17. WAS-VERTICAL VELOCITY (M/SEC) WITH RESPECT TO AIR
18. TX,TY,TZ-TRUE AIRSPEED COMPONENTS (M/SEC)
TXA=TS/SQRT(1+TAN(AA)*TAN(AA)+TAN(SA)*TAN(SA)
TYA=-TXA*TAN(SA) COMPUTE RELATIVE WIND DIRECTION VECTOR
TZA=-TXA*TAN(AA)
TRANSFORM FROM AIRCRAFT TO EARTH COORDS.
TXR=TXA
TYR=TYA*COS(RL)-TZA*SIN(RL) REMOVE ROLL
TZR=TYA*SIN(RL)+TZA*COS(RL)
TXP=TXR*COS(PC)-TZR*SIN(PC)
TYP=TYR REMOVE PITCH
TZP=TXR*SIN(PC)+TZR*COS(PC)
TX=TXP*SIN(HD)-TYP*COS(HD)
TY=TXP*COS(HD)+TYP*SIN(HD) REMOVE HEADING
TZ=TZP
19. W- VERTICAL WIND (M/SEC)
W=WGS-WAS
20. WX,WY-HORIZONTAL WIND COMPONENTS (M/SEC)
WX=GSx-TX
WY=GSy-TY
21. WS-WIND SPEED (M/SEC)
WS=SQRT(WX*WX+WY*WY)
22. WD-WIND DIRECTION (°)
WD= ° * ATAN2(WX,WY) - 180. , ° = 57.29578
IF(WD.LT.0.) WD = WD + 360.
23. GS-GROUND SPEED (M/SEC)
GS=SQRT(GSx*GSx+GSy*GSy)
24. TK-TRACK ANGLE (°)
TK= ° * ATAN2(GSx,GSy) , ° = 57.29578
IF(TK.LT.0.) TK = TK + 360.
25. DA-DRIFT ANGLE (°)
DA=TK-HD
IF(DA.GE.180)DA=DA-360
IF(DA.LE.-180)DA=DA+360
26. HT-HEIGHT OF STANDARD SURFACE (M)
TSA=288.15-0.0065*PA
HT=GA+(H-PA)*TV/TSA
WHERE H=1457m, 3012m, 5574m OR 7185m
27. SP-SURFACE PRESSURE (MB)
PAS=PA-GA*TSA/TV
SP=1013.25*(1.-PAS/44331.)**5.255883
28. EW-SATURATION VAPOR PRESSURE (MB)
EW=6.1078*EXP((17.6498*TA)/(243.17+TA))
29. RH-RELATIVE HUMIDITY (%)
RH=(E*(PS-EW)/EW)*100 , where E = EE / (PS - EE)
30. AMR-MIXING RATIO (G/KG)
AMR= 1000. * AMR
31. PT-POTENTIAL TEMPERATURE (° K)
PT=TN*(1000/PS)**(GO/GM)
32. ET-EQUIVALENT POTENTIAL TEMPERATURE (° K)
TL= ((TN-55.) * 2840.) / (2840.-(TN-55.)* ALOG(RH/100)) + 55.
ET = PT * EXP((3.376/TL-0.00254)* AMR * (1.+ .81*AMR/1000.))
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