Jirong Yu’s scientific contributions

What is this page?


This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (3)


Differential absorption lidar for searching water sources on Mars
  • Conference Paper

December 2024

·

1 Read

·

·

·

[...]

·

Jihong Geng

Line-by-line calculated CO2 absorption spectrum of the ν′(20011) vibrational band for T=150 °C and P=0.006 atm using the HITRAN Application Programming Interface (HAPI) software.
Pressure (a), temperature (b), and number density (c) profiles on Mars measured by Viking 1 (red) and fit (blue curves).
(a)CO2 absorption optical depth (AOD) using Eq. (2) from 60 km as TOA for Mars and (b) the absolute value of its change for a 1 MHz variation in laser frequency, i.e., the derivative of AOD relative to frequency. The elongated tails toward zero in panel (b) correspond to a trough or peak in panel (a). Some weak absorption lines that are not visible in panel (a) are enhanced in visibility in panel (b). The arrows indicate the selected online and offline laser wavelengths.
Conceptual diagram for master laser wavelength locking and control.
(a) Relative systematic error and (b) systematic error in pressure P as a function of altitudes due to a bias of 0.5, 1.0, and 2.0 K in temperature T, calculated using Eq. (12).

+2

Martian column CO2 and pressure measurement with spaceborne differential absorption lidar at 1.96 µm
  • Article
  • Full-text available

May 2024

·

47 Reads

·

1 Citation

By utilizing progress in millijoule-level pulsed fiber lasers operating in the 1.96 µm spectral range, we introduce a concept utilizing a spaceborne differential absorption barometric lidar designed to operate within the 1.96 µmCO2 absorption band for remote sensing of Martian atmospheric properties. Our focus is on the online wavelength situated in the trough region of two absorption lines, selected due to its insensitivity to laser frequency variations, thus mitigating the necessity for stringent laser frequency stability. Our investigation revolves around a compact lidar configuration, featuring reduced telescope dimensions and lower laser pulse energies. These adjustments are geared towards minimizing costs for potential forthcoming Mars missions. The core measurement objectives encompass the determination of column CO2 absorption optical depth, columnar CO2 abundance, surface atmospheric pressure, and vertical distributions of dust and cloud layers. Through the amalgamation of surface pressure data with atmospheric temperature insights garnered from sounders and utilizing the barometric formula, the prospect of deducing atmospheric pressure profiles becomes feasible. Simulation studies validate the viability of our approach. Notably, the precision of Martian surface pressure measurements is projected to surpass 1 Pa when the aerial dust optical depth is projected to be under 0.7, a typical airborne dust scenario on Mars, considering a horizontal averaging span of 10 km.

Download

Figure 1: Line-by-line calculated CO2 absorption spectrum of the (20011) vibrational band for T = 150 ⁰ C and P = 0.006 atm using the HITRAN Application Programming Interface (HAPI) software. The red arrow indicates the absorption line selected (i.e., P(10)) in this paper.
Figure 2: Pressure (left) and temperature (right) profiles on Mars measured by Viking 1 (red dots) and modeled (blue curves).
Figure 3: (a) CO2 absorption optical depth (AOD) for Mars and (b) its absolute value of change for a 1 MHz variation in laser frequency. The arrows indicate the selected online and offline laser wavelengths.
Figure 4: Conceptual diagram for master laser wavelength locking and control.
Figure 5: (a) Relative systematic error and (b) systematic error in pressure P as a function of altitudes due to a bias of 0.5 K, 1.0 K, and 2.0 K in temperature T, calculated using Eq. (12).
Martian column CO 2 and pressure measurement with differential absorption lidar at 1.96 µm

November 2023

·

70 Reads

By utilizing progress in millijoule-level pulsed fiber lasers operating in the 1.96 µm spectral range, we introduce a concept utilizing a differential absorption barometric lidar designed to operate within the 1.96 µm CO2 absorption band for remote sensing of Martian atmospheric properties. Our focus is on the online wavelength situated in the trough region of two absorption lines, selected due to its insensitivity to laser frequency variations, thus mitigating the necessity for stringent laser frequency stability. Our investigation revolves around a compact lidar configuration, featuring reduced telescope dimensions and lower laser pulse energies. These adjustments are geared towards minimizing costs for potential forthcoming Mars missions. The core measurement objectives encompass the determination of column CO2 absorption optical depth, columnar CO2 abundance, surface air pressure, as well as vertical distributions of dust and cloud layers. Through the amalgamation of surface pressure data with atmospheric temperature insights garnered from sounders and utilizing the barometric formula, the prospect of deducing atmospheric pressure profiles becomes feasible. Simulation studies validate the viability of our approach. Notably, the precision of Martian surface pressure measurements is projected to surpass 1 Pa when the aerial dust optical depth is projected to be under 0.7, a typical air borne dust scenario on Mars, considering a horizontal averaging span of 10 km.