What is Metric: Definition and 1000 Discussions

METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is a computer model developed by the University of Idaho, that uses Landsat satellite data to compute and map evapotranspiration (ET). METRIC calculates ET as a residual of the surface energy balance, where ET is estimated by keeping account of total net short wave and long wave radiation at the vegetation or soil surface, the amount of heat conducted into soil, and the amount of heat convected into the air above the surface. The difference in these three terms represents the amount of energy absorbed during the conversion of liquid water to vapor, which is ET. METRIC expresses near-surface temperature gradients used in heat convection as indexed functions of radiometric surface temperature, thereby eliminating the need for absolutely accurate surface temperature and the need for air-temperature measurements.

The surface energy balance is internally calibrated using ground-based reference ET that is based on local weather or gridded weather data sets to reduce computational biases inherent to remote sensing-based energy balance. Slope and aspect functions and temperature lapsing are used for application to mountainous terrain. METRIC algorithms are designed for relatively routine application by trained engineers and other technical professionals who possess a familiarity with energy balance and basic radiation physics. The primary inputs for the model are short-wave and long-wave thermal images from a satellite e.g., Landsat and MODIS, a digital elevation model, and ground-based weather data measured within or near the area of interest. ET “maps” i.e., images via METRIC provide the means to quantify ET on a field-by-field basis in terms of both the rate and spatial distribution. The use of surface energy balance can detect reduced ET caused by water shortage.
In the decade since Idaho introduced METRIC, it has been adopted for use in Montana, California, New Mexico, Utah, Wyoming, Texas, Nebraska, Colorado, Nevada, and Oregon. The mapping method has enabled these states to negotiate Native American water rights; assess agriculture to urban water transfers; manage aquifer depletion, monitor water right compliance; and protect endangered species.

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  1. P

    A Gauge Invariance of Transverse Traceless Perturbation in Linearized Gravity

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  2. J

    I Metric Signature Choice & Physical Consequences: Exploring Pin(1,3) & Pin(3,1)

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  3. M

    Conservation law for FRW metric

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  4. robphy

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  5. S

    I Spherically Symmetric Metric: Is Singularity Free?

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  6. George Keeling

    A Exploring Null Basis Vectors, Metric Signatures Near Kruskal

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  7. Q

    I Metric Tensor: Symmetry & Other Constraints

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  8. JD_PM

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  9. K

    I Vanishing of Contraction with Metric Tensor

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  10. J

    I Metric defined with a non-coordinate basis

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  11. Q

    A Can you numerically calculate the stress-energy tensor from the metric?

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  12. Buzz Bloom

    I Formula: velocity of circular orbit wrt Schwartzschild metric

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  13. Buzz Bloom

    I Question re spacial curvature K(r) w/r/t the Shwarzchild metric

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  14. Math Amateur

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  15. H

    A Metric Form of ##g_{μν}## - Solving a Challenge

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  16. V

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  17. S

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  18. E

    A Time Measurement in Friedman Metric: Physically Possible?

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  19. Q

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  20. S

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  21. N

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  22. E

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  23. P

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  24. M

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  25. D

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  26. George Keeling

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  27. D

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  28. R

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  29. R

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  30. Q

    I Minkowski Metric: When to Use It

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  31. M

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  32. W

    I Raising/Lowering Metric Indices: Explained

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  33. Arman777

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  34. P

    I Active Diffeomorphisms of Schwarzschild Metric

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  35. A

    Coordinate transformations on the Minkowski metric

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  36. W

    MHB Forecasting metric using regression. Is this a sound approach?

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  37. Pencilvester

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  38. George Keeling

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  39. J

    I How do charts on differentiable manifolds have derivatives without a metric?

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  40. S

    I Godel metric in a cylindrical chart

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  41. W

    Solving Metric Tensor Problems: My Attempt at g_μν for (2)

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  42. Math Amateur

    MHB Exploring Theorem 4.29: Compact Metric Spaces & Inverse Functions

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  43. K

    I Is this the only form of the Minkowski metric?

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  44. Math Amateur

    MHB The Metric Space R^n and Sequences .... Remark by Carothers, page 47 ....

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  45. K

    Introduce Newtonian Metric for SR & Lorentz

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  46. Math Amateur

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  47. J

    I Does G effectively change in an expanding metric?

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  48. K

    I Metric Nomenclature: Lorentz & Minkowski

    Can I say that the Lorentz metric is the specific form ##-c^2dt^2 + dx^2 + dy^2 + dz^2## whereas the Minkowski metric is the metric of Minkowski space which can take the Lorentz form I just gave, but can also, e.g., be written in spherical coordinates?
  49. T

    Did I Get These Metric Tensors Right?

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  50. D

    I Trying to construct a particular manifold locally using a metric

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