Caltech EM27/SUN FTS

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Version as of 21:56, 19 Sep 2020

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We anticipate using this mobile intrument in conjunction with TCCON instruments (e.g. the one at Caltech) to provide ground validation for and check for biases in OCO-2.   We also anticipating using this instrument to examine emissions of various gases from point locations and sources in the South Coast air Basin (SCB).



Resolution: 0.5 cm-1

Geometric distance moved: 0.45 cm

Optical path difference: 1.8 cm

Range: ~40009000 cm-1

Gases measured (expected): CO2, CH4, CO, H2O, N2O, O2





  • USB GPS (Amazon)
  • Compass (Dick's Sporting Goods)
  • Bubble level (from OSH)
  • Extension Cord, 100 ft (Home Depot)
  • Cord storage (Home Depot)
  • Surge Protector (Home Depot)
  • Laptop ordered from Amuras Computers (PANASONIC TOUGHBOOK 53 (CF-53SALLYLM)), May 13 Programs to install
    • OPUS (by Bruker)
    • Suntracker (by Bruker)
    • MATLAB
    • Office Suite
    • WinSCP
    • PuTTY
    • Firefox
  • Router (currently loaned out to LANL)
  • Network cables (may already have enough)
  • Weather station (we have an extra Zeno lying around in lab), for pressure, humidity, and temperature and hopefully wind speed/direction
  • Cart and/or encasing.  Needs:
    • Hold EM27 + cords + etc., while making measurements and storing
    • Transport
    • Some protection from weather ?
    • Absorb some bumps/shocks


Considering for future (depending on goals/needs)

  • Portable power source, estimated draw of 75130 W.  ESTIMATES  EM27: ~40 W (avg) 80 W (max),  laptop: 1560 W (may be able to run off own battery),  Weather station: ~10 W ??,  Router: ~1020 W (may be unnecessary when going portable, depends on if everything can be connected to laptop).  OPTIONS:
    • UPS ~$40$200, estimate runtime 1–4 hrs
    • YETI 400 ~$500, estimated runtime 2.56.5 hrs
    • Ark-pak ($400) + battery (~$100), estimated runtime: 12 hrs/full day depending on battery capacity
    • DC/AC inverter ($40) + battery charger ($70) + battery ($100), estimated runtime: 12 hours/full day depending on battery capacity
  • HCl Calibration cell (slot for a 40 mm diameter, 40 mm length cell but may need external), or need to work on method to watch instrument line shape (ILS)




May 28, 2014

Baron from Bruker unpacked and set up the initial install of the instrument.  Total time was less than 4 hours.  Had some problems with the ellipses in the camtracker progam.  Had to make adjustments to Configureation file, located in the same directory as the tracker program.  Changed settings to what was in the manual, and then made additional adjustments from there.

Acquired lamp spectra with filter in place to look for ghosts.  Doubling ghost was present as were laser sampling error ghosts.  Tried to eliminate them using the xsm command, but there was a bug so we were unable to.  Camille will email Bruker.