ACE-EPAM 24 Hour Table Header Description

This page describes the table headers on the 24 hour ACE EPAM table. There are a few points to keep in mind
when looking at the ACE-EPAM 24 hour data. The ACE-EPAM 24 hour data is scraped from the follwoing FTP site:

ftp://mussel.srl.caltech.edu/pub/ace/browse/EPAM/EPAM_quicklook.txt

You can point your browser there to see the latest data. As you see, each data point has a time stamp.
ACE data dumps couver roughly 3 days. So every 24 hours a new day's worth of ACE data appears at the end
and the earliest day's worth of data is removed.

Next, the orbits are obtained by reading the latest "*.orp" file (e.g. DO16207.orp). For the purposes of orbital
fluence calculations, an "orbit" is defined as the time between RADMON ENABLE and RADMON DISABLE.

It is important to note that there is no coordination between the time span of the ACE data and the
start/stop of an orbit. Therefore when a new ACE data dump appears, the data might not entirely span the
last orbit in which it appears - only a fraction of the orbit "has" ACE-EPAM data within that orbit.
This fraction is displayed under the heading of "Orb. Frac." - i.e. Orbital Fraction.
The next data dump that appears will fill out the rest of that orbit.

1. Altitude

This is the present altitude of the Chandra Observatory.

2. Plot

Clicking on this active link will bring up a plot of the latests ACE data from the Caltech FTP page.
This data will contain three days worth of data. It is updated every 24 hours.

Important! The data on this FTP site is updated once every 24 hours.
Therefore the displayed in this plot is anywhere from 30 minutes to 24 hours old.

3. Last P3

This is the last, unattenuated P3 value in the FTP file. Again it can be
anywhere from 30 minutes to 24 hours old.

4. Last Att. P3

This is the last P3 value in the FTP file adjusted for gratings and instrument status. Again it
can be anywhere from 30 minutes to 24 hours old.

5. Orb. Att. P3 FLU

This is the calculated fluence for the last orbit which contains any ACE P3 flux data values. Note that this
is not necessarily the satellite's present orbit. This is due to the fact that the appearance of the
ACE-EPAM 24 hour data is in no way coordinated with Chandra orbits.

6. Orb. Frac.

The fraction of time ACE data exists, within the last orbit that contains any ACE-EPAM data.

Year Att. P3 FLU

The summation of the orbital fluence since January 1 of the present year.
NOTE: This program was begin in early August, 2016. So for 2016 the yearly summation was from August onward.