Steps In MTP Post-Campaign Data Analysis

MJ Mahoney

1. Substitute NAV Pressure and Temperature

Most research aircraft provide a 1 Hz navigation data stream for information such as Universal Time, latitude, longitude, aircraft attitude, pressure altitude and outside air temperature. The MTP records some of this information in the A-line of a RAW data file -- the aircraft attitude, pressure altitude and outside air temperature being the most important for the MTP. Since this information is not PI maintained, it's quality can be questionable. Generally there is a PI maintained in situ pressure and temperature measurement because of its fundamental importance. If other sources of pressure and temperature are available, they should be substituted into the A-line of the RAW file.
images/Substitute_P_T.png

Figure 1. The MTPbin Pgm Setup tab.

As shown in Figure 1, this is done in the RAW File Options frame on the MTPbin Pgm Setup tab. By default, the Use OAT, Use pALT, and Rename New File check boxes are checked. Use the Source combo box to select the two-letter descriptor for the source of the P and T data. Current descriptors are:

Descriptor	Comment
NO	None
UC	M55 UCSE data
TD	M55 Thermo Dynamic Complex (TDC) data
MM	NASA Ames Mission Meteorological System (MMS) data
PT	NOAA Aeronomy Laboratory Pressure and Temperature
NC	NASA Dryden NC data
IC	NASA Dryden ICATS data
IN	NASA Dryden IN data
FT	NASA Dryden FT data

Finally, click the Substitute P and T data into A-line of button to perform the substitution, generally into the RAW file. To avoid confusion over whether or not P and T data has been substituted into the RAW file, the extension is changed to RXX, where XX is the two-letter descriptor. For example, when TDC P and T is subsituted into the A-line of the RAW file, a new file is created with the extension RTD.

After the substitution has been done, the Source combo box will revert back to NO. To use the RXX file for data processing, change the Source combo box to whatever XX is; for example, TD. Then check the Use Substituted RAW check box. This will change Open RAW button on the right side of the MTPbin form to Open RTD. It will also change the RAW File text box on the FLTINFO Gain tab to RTD.

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