Convair 580 Bulk/all-the-rest Parameters

This is the version 02 release and most of these parameters are in their final form.  Exceptions are detailed below.  Please take the time to read all of this file.

Reference is sometimes made to “m200” and “m300”.  These were the primary data acquisition systems used aboard the Convair-580 aircraft during ISDAC.

Many of the parameters included below are averaged versions of high-frequency data previously released by IAR/NRC. There are some parameters included below that are derived from the data released by IAR/NRC. 

Two files holding take-off to touchdown time intervals are provided.  All flights that took place in Alaska are included, even flights that did not go to or from Barrow airport. The file ‘TO_TD_v2.Tim’ holds flight times with flight numbering from 1 to 28.  The file ‘TO_TD_v3.Tim’ holds flight times with flight numbering according to the NRC convention used in the field.

When referring to particular flights one should state which flight numbering convention used or just use the date.  The NRC flight numbering convention is used in this document.

If you are interested in extreme conditions, flight 14 on April 5th was all in cloud or precipitation, while flight 18 is extremely clear of both.  From an aerosol point of view, on April 19 smoke from Siberia was encountered.

Yet To Be Delivered

MSC/Environment-Canada has delivered most of the intended data-sets in final form at this point.  However there are still some odds and ends that we are currently working on.  Here is a short list:
•	The condensed water concentrations provided by the Nevzorov hot-wire probes will be provided as soon as Alexei Korolev processes the data, if the data is truly viable.
•	A new version of the 2D image analysis will be made using the final versions of 1D parameters included in the bulk parameters data.
•	Updated radar imagery from the MSC 35 GHz aircraft radar.
•	Channel size info for the FSSP100X-096 based on calibrations performed in the field.
•	Documentation related to the aerosol inlet system and estimates of wall losses along the inlet lines.
•	More documentation of all sorts including an updated version of the Instrument QC Overview.
•	An updated version of the aircraft radiometer data from either MSC or Chuck Long. 

File Format
Both space and comma-delimited versions of ASCII files are provided. In each file you will find 6 lines of header information at the top of the file.  In the column-delimited files the time is separated into hours, minutes and seconds.  In the space-delimited files, the hours, minutes and seconds are not separated by spaces.  Each row represents 1 second of data and times mark the beginning of the sample interval from the data-acquisition system point of view. Missing data is signified by negative number consisting of only the digit ‘8’.  All data values that are larger than the data-format used are signified by a negative number consisting of only the digit ‘9’.  In each case the exact number used depends on the format used for the column.

Two folders are provided, one that holds space-delimited files, and one that holds comma-delimited files.  The data held in the files are otherwise identical.  The columns of data, as identified by the column titles, are listed below:

UTC Time --> the true GMT time, hours minutes seconds

DAS Time --> the data acquisition system time, in this case the M200 time, hours minutes seconds.

ThkAlt  an MSL altitude that starts at the runway MSL altitude at takeoff and is adjusted each second based on pressure changes and density. Note that any interruption in the data stream makes this non-viable for the remainder of the flight.  Also, atmospheric changes over the course of the flight tend to make this altitude wander.  However it should be fairly accurate in the first few hours of flight.

PreAlt  a pressure based altitude similar to those released by IAR/NRC except that it is more available.  This altitude is is equivalent to the air pressure at mean sea level (MSL) in the International Standard Atmosphere (ISA).

ALT_G  this is the GPS Orthometric Height.  This is the same as the NovaTel GPS altitude provided by IAR/NRC.  This is actually a height above a geoid that is a good estimation of sea level.  Unfortunately this signal was very noisy and less available than the other altitudes for the entire project.  It has very limited usefulness.

NPres  corrected static air pressure from IAR/NRC; it’s likely the best version when available.

BCPres   corrected static air pressure (estimated) from the pod position; not the best version but good availability.

KT-19  Temperature at earth surface OR at top layer of a cloud below; this uses a passive IR thermometer/radiometer that is focused downward with a narrow range directions.

RSTem  Port static temperature from voltages; this is the best version of outside air temperature with good availability.

RFTS  Reverse flow static temperature from voltages; also a fairly good version of outside air temperature which should be the best in icing conditions. Note! The temperatures and dew-points provided here differ from those provided IAR/NRC by several degrees.  Those provided here have been extensively checked against those provided by the airports at takeoff and touchdown over several polar projects.  
EGGDew  EG&G chilled mirror dew point from voltage; some voltage dropouts in some flights but generally good. These chilled mirror type devices seem to alternate between being a dew-point and a frost-point.  This device has good availability.

ReHuW  Relative humidity with respect to water; we used the EG&G dew point in this formulation (see EG&G notes above).

ReHuI  Relative humidity with respect to ice; Same comments as REHuW.

LicDew  LiCor dew point; No data until April 13 Flt18, very limited availability but when it did work, it was by far the best of the dew/frost points.

LicFro  LiCor frost point; Same comments as above

BmTAS  Boom/Pod true air speed; may not be the best version of true air speed (those provided by IAR are likely the best); very good availability.

BmLAS  Boom/Pod local air speed from voltage; as measured by the scaler boom below the wing, at “probes” location.

HDG  Litton aircraft heading in degrees from true north; this is the same as that provided by IAR/NRC.

TRK  Litton aircraft track angle in degrees from true north; this is the same as that provided by IAR/NRC.

ALPHA  Litton aircraft angle of attack; this is the same as that provided by IAR/NRC.

BETA  Litton aircraft angle of attack; this is the same as that provided by IAR/NRC.

PITCH  Litton aircraft pitch angle; this is the same as that provided by IAR/NRC.

ROLL  Litton aircraft roll angle; this is the same as that provided by IAR/NRC.

driftA  Litton aircraft drift angle; this is the same as that provided by IAR/NRC.

MastrLAT  a latitude constructed from all available position data; construction details are provided below.  The intent in constructing this parameter was to maximize the availability; data gaps have been filled.

MasterLON  a latitude constructed from all available position data; (same comments as MastrLAT above).

PosStat  an index that indicates how the ‘MasterLat’ and ‘MasterLon’ were constructed; details are provided below.

Brg01  Bearing from aircraft to Site#1 where Site#1 is the ARM Barrow Site at the North Slope of Alaska: 71° N 19.378' ; 156° W 36.934'

Range01  Range from aircraft to Site#1 where Site#1 is the ARM Barrow Site at the North Slope of Alaska: 71° N 19.378' ; 156° W 36.934'

MWSpd  Master Wind Speed; a wind speed constructed from all available wind speed data; Wind speeds have been are nulled where ever wind directions have been nulled by IAR/NRC.

MWDir  Master Wind Direction; a wind direction constructed from all available wind direction data with the intent of increasing the availability.

VWND_P  Pod vertical wind speed (up is positive); this is the same as that provided by IAR/NRC.

NevCExt  Nevzorov Corrected Extinction; Unlike all of the rest of the parameters, this parameter has been set to the value zero whenever no data is available.  Zero is a valid value but it better to treat all zero values as a null value (ie indicating missing data).

R96  FSSP100x s/n 096 range indicator; 0-3 are valid with zero indicating the widest range and 3 the narrowest.

F96CncX  FSSP100x s/n 096 coincidence and dead-time corrected total droplet/particle concentration.

R02  FSSP100x s/n 002 range indicator; 0-3 are valid with zero indicating the widest range and 3 the narrowest.

F02XCnc  FSSP100x s/n 002 coincidence and dead-time corrected total droplet/particle concentration.

F3c>2um  FSSP300 Total concentration of particles greater than 2 microns.

F300Cnc  FSSP300 Total concentration of particles.

KSzrLW  King(a hotwire probe) zero-removed liquid water concentration; sensitive to liquid water only.

CSI_TCWC  CSI Total condensed water concentration; sensitive to larger ice particles (depending on counter-flow); no time-shift was performed to compensate for the small lag resulting from response time of this probe.  No data is available for flights 11&12 (flows set up badly), 16,17 & 18(blown fuse) and Flt 33(not turned on).

CSITCWzr  CSI TWC for flights 8-10; the TDL was defective on these flights and this is our attempt at rescuing the CSI data from these flights by employing a correction that is a function of air pressure. This parameter should be null for all of the other flights but it currently has values equal to CSI_TCWC above.

ROSIC1  Rosemount icing detector voltage.

RIDInd  Rosemount icing detector indicator; values correspond to:
-3000	non zero signal points
-1900	bad data points
-1500	unusable points because of a trip
-1000	minimum point for a trip
-1300	unusual drop off in the voltage signal
0	zero signal points
2000	maximum point prior to a trip

2DC0ShdOr  Concentration of particles if all 2DC images were valid

2DP1ShdOr  Concentration of particles if all 2PC images were valid

PCTcon  PCASP total aerosol particle concentration

CVIFlg  CVI inlet flag, 0=aerosol inlet, 1=CVI inlet

CVISamP --> CVI inlet line pressure

CVISamT --> CVI inlet line temperature

CVISampFl --> CVI sample flow; this is a mass flow (ie it is in “standard” litres per minute)

CVI_Eh  CVI enhancement factor; (whenever CVIFlg=1)

Notes Regarding Master Latitude and Longitude

Due to unknown reasons the NovaTel GPS system aboard the aircraft kept losing contact with some of the satellites required to perform the geometric trilateration required to compute the GPS aircraft position. The position data submitted by IAR/NRC had a significant amount of missing data.  In an effort increase the availability if position data an assessment of all position data available lead to method for constructing a good approximation of the true location often using the Litton (non-GPS) position.  We were able to construct a new position by linearly interpolating the difference between Litton and GPS Latitudes and Longitudes before and after a gap in the data. Afterward we could see how good our estimation across the gap faired by plotting the bearing and range from the Litton position to the augmented GPS position. In general the uncertainty in the location obtained from looking these plots is at maximum ~8km. There are a few other times when the position uncertainty might be much higher and these are indicated below.

Flight	Comment
08		Default is Honeywell, No action periods

09		Default is GPS, interpolate through 3 periods

10		Default is GPS, Substitute in Litton & offset for 1 period, interpolate 2nd period

11		Default is GPS, In 3 periods substitute in Litton plus an offset

12		Default is Honeywell, No action periods

13		Default is GPS, In 8 periods substitute in Litton & offset

14		Default is Honeywell, No action periods

15		Default is GPS, In 5 periods substitute in Litton & offset, then interpolate across missing parts

16		Default is GPS. Interpolate across the missing parts

17		Default is GPS. In 4 periods substitute in Litton & offset, then interpolate across missing parts

18		Default is GPS. In 1 periods substitute in Litton & offset, then interpolate across missing part
19 		Default is GPS. In 1 periods substitute in Litton & offset, then interpolate across missing parts

20		Default to GPS.  In 1st file substitute in Version of GPS we got when in the field and substitute in offset versions of the Litton that we got when in the field.  Then interpolate across all missing parts.  In the 2nd file (after MSC DAS crash) do the same expect use the post Project version of IAR GPS when it becomes available, again interpolating across gaps after all substitutions are implemented.  All data is missing for the final descent/landing. Note! A much higher error/uncertainty exists in the first ½ to 2/3 of this flight.  The position may be off for as much as 2 km at times.

21		Default is Honeywell, No action periods

22		Default is GPS, interpolate through 1 period

23		Default is GPS. In 4 periods substitute in Litton & offset.

24		Default is GPS. Interpolate across missing part (only 1 short period).

25		Default is GPS. Interpolate across missing part (only 1 short period).

26		Default is Honeywell, No action periods.

27		Default is GPS, interpolate through 1 period.  Then for ~ last 2/3 of flight build a position based on Litton + static offset. Note! A much higher error/uncertainty exists in this last 2/3 of flight. 

28		Default is Honeywell. Substitute in Litton & offset for 1 period

29		Default is Honeywell, No action periods
30		Default is GPS. In 2 periods substitute in Litton & offset, then interpolate across missing parts.

31		Default is GPS. In 4 periods substitute in Litton & offset, then interpolate across missing parts

32		Default is Honeywell, No action periods

33		Default is GPS. Interpolate across the missing parts.

34		Default is GPS. In 4 periods substitute in Litton & offset, then interpolate across missing parts. For the final period after 05:24:03, the original version of Litton is substituted in and then offset. Note! A much higher error/uncertainty exists in final 18 minutes of flight.

35		IAR/NRC did not supply data for this flight.  No master latitude and longitude exists for this flight.

An index, named ‘PosStat’ in the ascii tables provided here, was archived to indicate what actions were performed to construct the master position for each second.  A single digit index implies that a default choice of position was made and no further action was performed.  A double digit index indicates that the default position was acted upon in some way (the first digit gives the action and the 2nd digit gives the choice of default).  A triple digit index indicates that a 3rd action was performed (action#1 choose a default, action#2 act upon default for specific periods), which was to interpolate across all gaps in the data.

In general larger values of this index indicate that a greater number machinations were employed to construct the new location.

Notes Regarding Master Wind

In general the pod winds were used as the default.  Only in flight 16 did we use the Honeywell winds.  Often were able to use the original version of Pod winds received in the field because they did not differ from the post-project version of Pod winds and were not nulled out for excessive periods of time by IAR/NRC.

In all cases the wind speed was nulled by us whenever the wind direction (only) was nulled by IAR/NRC.