Caltech EM27/SUN FTS

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Version as of 20:13, 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
  • 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)