Dec 22, 2015 - Programming language: Python and ArcScript. Plot: matplotlib ... Search for people, jobs, companies, and more. ... App Store? qz.com..
12/22/2015
Realtime simulation of the iterative calculation of the satellite based surface energy fluxes | Ramesh Dhungel | LinkedIn
Working at Atlassian? Subscriptions to Safari fully reimbursed by Atlassian. Unlimited access!
Ramesh Dhungel
Edit post
Water Resources, Remote Sensing and Land Surface Modeler (LSM) (Ph.D. Civil Engineering)
View stats
Realtime simulation of the iterative calculation of the satellite based surface energy fluxes Dec 21, 2015
92 views
1 Like
0 Comments
This will be a continuing post which will be updated until most of the real time simulations are shown. White paper An iterative procedure is still used to converge fluxes in evapotranspiration (ET) calculation in many ET models like METRIC, SEBAL and SEBS. In this post, a realtime simulation is shown to expedite the satellite based surface energy balance fluxes in low wind speed condition. In the surface energy balance, stability correction of aerodynamic resistance is necessary as it affects the computation of sensible heat flux. The MoninObukhov stability length (L) can be calculated either from an iterative process using wind profiles, temperature and humidity or through more complicated measurements of wind speed, sensible heat flux, and latent heat flux. The MoninObukhov similarity functions are used https://www.linkedin.com/pulse/realtimesimulationiterativecalculationsatellitebaseddhungel?trk=profpost
1/29
12/22/2015
Realtime simulation of the iterative calculation of the satellite based surface energy fluxes | Ramesh Dhungel | LinkedIn
to define momentum (ψm) and heat (ψh) stability correction. While computing MoninObukhov similarity functions, a set of the equations must be solved iteratively as friction velocity (u*) and MoninObukhov length (L) are interdependent. These variables should be revised until the parameters of the surface energy balance converge within prescribed limits between successive iterations. Some technical details:
Figure 1: Improved Methodology ( Dhungel et al., 2014) Programming language: Python and ArcScript Plot: matplotlib Date of the satellite overpass: 05/17/2008 (Landsat 5) Weather data NARR (32 km resolution)
https://www.linkedin.com/pulse/realtimesimulationiterativecalculationsatellitebaseddhungel?trk=profpost
2/29
12/22/2015
Realtime simulation of the iterative calculation of the satellite based surface energy fluxes | Ramesh Dhungel | LinkedIn
Area: Southern Idaho near Raft River Number of pixels: 1455408 Area: 1300 km2 Convergence criteria: Convergence of aerodynamic resistance within + 1 second / meter Computer System (Hardware for simulation) System properties: Intel ® Core (TM) i74790 CPU @ 3.6 GHz Installed memory (RAM): 32 GB System type: 64bit Operating System Software for simulation recording eLecta Live Screen Recorder Realtime simulation (% convergence of aerodynamic resistance with number of iteration) T_cells= Total cells C_cells= Converged cells N_cells= Nonconverged cells T_cells = C_cells + N_cells P_Convg = float(C_cells)/T_cells * 100.0000 N = 50 y= P_Convg colors = np.random.rand(N) s = 8 * iteration ** 1.2 plt.scatter(iteration, y,s,c=colors,alpha=0.5,marker=(5, 3),zorder=2)
https://www.linkedin.com/pulse/realtimesimulationiterativecalculationsatellitebaseddhungel?trk=profpost
3/29
12/22/2015
Realtime simulation of the iterative calculation of the satellite based surface energy fluxes | Ramesh Dhungel | LinkedIn
plt.hold(True) stop=time.time() test=(stop start) / 60 test1=("%.2f" % test) plt.title('Improved Methodology Minutes=%s' % test1, fontsize=18) Increased dots means increased % of convergence: Wind speed at set 0.8 m/s (minimal value) to understand the extreme behavior. Traditional Methodology (97.5 % convergence of pixels (0.8 m/s wind speed at 30 m), process manually stopped at about 70 minutes)
Figure 2: Realtime simulation graph
https://www.linkedin.com/pulse/realtimesimulationiterativecalculationsatellitebaseddhungel?trk=profpost
4/29
12/22/2015
Realtime simulation of the iterative calculation of the satellite based surface energy fluxes | Ramesh Dhungel | LinkedIn
Real-time simulation of the surface en...
Realtime simulation (videoOnly instantaneous time of convergence is recorded to reduce the recording time) Improved Methodology (99.5 % convergence of pixels (0.8 m/s wind speed at 30 m), process automatically stopped at about 13 minutes)
Home
Pulse
Profile
Interests Jobs Figure 3: Realtime simulation graph
Connections
Publish a post
Search for people, jobs, companies, and more...
Realtime simulation of the Advanced iterative calculation of the satellite based surface energ…
1
https://www.linkedin.com/pulse/realtimesimulationiterativecalculationsatellitebaseddhungel?trk=profpost
5/29
12/22/2015
Realtime simulation of the iterative calculation of the satellite based surface energy fluxes | Ramesh Dhungel | LinkedIn
Ramesh Dhungel
Real-time simulation of the surface en...
What's Really Behind Skyrocketing Drug Prices? Bill George
Space Past Failure: The Musk of Zero David L. Katz, MD, MPH,...
From Oprah to Richard Branson, the Biggest Names in Business Share How They… Florencia Iriondo Made it SpaceX Successfully Lands Rocket After Launch of Satellites Into Orbit www.nytimes.com
Realtime simulation (videoOnly instantaneous time of convergence is recorded to reduce the recording time) For the further reading, references and to cite the work, please refer the following literature.
The Top 6 GoodNews Stories of 2015
Dhungel, Ramesh, Richard G. Allen, Ricardo Trezza, and Clarence W. Robison.
Bill Gates
"Comparison of Latent Heat Flux Using Aerodynamic Methods and Using the Penman–Monteith Method with SatelliteBased Surface Energy
Can Phil Schiller fix the Apple App Store?
Balance." Remote Sensing 6, no. 9 (2014): 88448877.
qz.com
Dhungel, R.; Allen, R. Time Integration of Evapotranspiration Using a Two Source Surface Energy Balance Model Using NARR Reanalysis Weather and Satellite Based METRIC Data. Ph.D. Thesis, University of Idaho, Kimberly, ID, USA, 2014 http://digital.lib.uidaho.edu/cdm/ref/collection/etd/id/829 Dhungel et al., 2015. Improving iterative surface energy balance convergence for satellitebased flux calculation, 15804L. Journal of Applied Remote Sensing (Underreview).
Written by
Ramesh Dhungel
Like
Comment
https://www.linkedin.com/pulse/realtimesimulationiterativecalculationsatellitebaseddhungel?trk=profpost
1 like 0 comments
6/29
