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On board the T28 aircraft was a Hail Spectrometer and High Volume Particle Spectrometer (HVPS). Both probes output 2D data, and the Hail Spectrometer also output 1D data. The HVPS had an array of 256 diodes, the Hail Spectrometer had 126/64 diodes for 1D/2D data. If image elements were blocked above a certain threshold a particle(s) would be counted. The steps to use these counts to calculate particle concentration (#/m^4) are detailed below.

Notes for self

• np.ceil or np.round
  • for cases where 1 count, but soda does correction of * 1.1 / 5
    • so the 1 count would be 1 *1.1 /5 = ~.2 does the .2 count as a count since the /5 is a result of the 5 seconds?
• hail counts from disp count forward. so 241841 is 41 42 43 44 45
• cant say i understand it but in aarons code, the counts are multiplied by the 1.1 correction factor. then the conc is /5 which is the active time.
  • what doesn't make sense is that the counts are ~5x higher than the disp file, which is wrong because when the concentration is calculated, it takes into account that 5x factor and becomes decently close to the disp calculated conc
  • what also doesnt make sense is that the concentration from calculating it myself, using that /5 and *1.1 is that the concentration i calculate is consistently ~1.1 times higher than the concentration aaron gets.
    • could i be looking at the wrong code
• ok update to previous bullet point. just not multiplying by 1.1 seems to be the move???
  • i think im missing where in aarons code he actually makes the concentration file because something is off here
    • and im still confused about why the counts should be /5 but thats not the step that I see taken in the code
• aaron takes conc1d and prints it to the ascii file and does nothing with it except format it

Ok so, notes for making this page.

• all the counts check out. would be good to show this and include where the time starts
• the sample volume checks out. show this too, but not all the soda details. but a comparison of numbers would be good
• explain the differene between sodas counts and the disp counts and how if you divide by 5 theyre the saame but im not sure why. however, it works out in the concentration with the divide by 5
  • the counts are multipliued by a correction factor 1.1
• with all that considered the concs match well and the math was reproducable using the counts from soda and the numbers, and the conc ultimately lines up decently with the 1D
• the corr fac is the poisson corr factor
  • not sure why this is needed tho
• the active time correction is for how ever long the chunk is
  • not sure why it should be divided by 5? figure it should be a sum so no need for division but oh well it works so whatever
• why the 126/64 diode change?