[OpenMadrigal-users] NEL without POPL?

[Jan Philipp Bornebusch]

Hi!
I hope you are the people to ask, if not I apologize.
My problem is this:
Using ISPrint Database Browser I have downloaded EISCAT-Data. I am mostly 
interested in electron densities, so I downloaded NEL and POPL. It seems 
that NEL as the corrected electron density should be derived from POPL, the 
uncorrected electron density. Indeed I found that POPL, TI and TR are used 
to do that and how it's 
done.(http://www.eiscat.com/madrigal/cedarFormat.pdf) So far, so good. But 
how is it possible that there are values for NEL when there are none for 
POPL?
I'll give a specific example:
I chose the EISCAT Svalbard IS Radar Longyearbyen on November 1st 2003. The 
tau0 experiment is run. Start Time: 11/01/2003 00:00:15, End Time: 
11/01/2003 23:59:11
For this period of time I choose to download:
UTH, GDALT, NEL, POPL
Because I'm interested in low altitudes, I apply the filter Max Altitude < 
150 km (at the top).
What I get is NEL starting from around 90 km altitude and POPL starting from 
about 120 km altitude. How is that possible? What does it mean?
I will cut and paste a small excerpt from the output to this e-mail, so yo 
know what I mean.
Thanks for any kind of help you can provide,

Jan


EISCAT Svalbard IS Radar Longyearbyen: 11/01/2003 0002:23-0003:27
       UTH      GDALT        NEL       POPL
    0.049      77.86     missing    missing
    0.049      80.83     missing    missing
    0.049      85.17     missing    missing
    0.049      89.73     missing    missing
    0.049      92.69      9.979     missing
    0.049      97.54     10.020     missing
    0.049     101.59     10.879     missing
    0.049     104.56     10.095     missing
    0.049     108.95     10.495     missing
    0.049     113.46     missing    missing
    0.049     117.68     10.776     missing
    0.049     125.70     10.849     missing
    0.049     132.82     10.934     missing
    0.049     140.86     10.860     missing

EISCAT Svalbard IS Radar Longyearbyen: 11/01/2003 0002:23-0003:27
       UTH      GDALT        NEL       POPL
    0.049     118.32     missing   10.4660
    0.049     121.29     missing   10.5060
    0.049     124.26     missing   10.5000
    0.049     127.22     missing   10.5160
    0.049     130.19     missing   10.5520
    0.049     133.16     missing   10.5620
    0.049     136.12     missing   10.5960
    0.049     139.09     missing   10.6130
    0.049     142.05     missing   10.6470
    0.049     145.02     missing   10.6690
    0.049     147.99     missing   10.6830