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. J

    Spacetime Interval & Metric: Equivalent?

    This may seem an odd question but it will clear something up for me. Are "The spacetime interval is invariant." and the "The spacetime metric is a tensor." exactly equivalent statements? Does one imply more or less information than the other? Thanks!
  2. K

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  3. G

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  4. C

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  5. T

    Understanding Einstein Field Equation & Metric Tensor

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  6. E

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  7. N

    Experimental determination of the metric tensor

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  8. M

    Understanding the Metric Tensor: A 4-Vector Perspective

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  9. binbagsss

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  10. binbagsss

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  11. binbagsss

    Form of Rienmann Tensor isotrpic & homogenous metric quick Question

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  12. P

    Ricci tensor of schwarzschild metric

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  13. Berlin

    Does the Square Root of the Inverse Metric Unify Geometry and Physics?

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  14. C

    Null geodesics of the FRW metric

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  15. Einj

    Understanding the FRW Metric: Exploring Physical and Comoving Coordinates

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  16. C

    Determining Metric of Space-Time (H.P. Robertson 1949)

    In a paper published in Reviews of Modern Physics in 1949, http://journals.aps.org/rmp/pdf/10.1103/RevModPhys.21.378 , H.P. Robertson provided an analysis of the physical implications of the Michelson/Morley, Kennedy and Thorndike, and Ives and Stilwell experiments which seems definitive with...
  17. S

    How did Einstein derive the meaning of Schwarzchild's metric

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  18. Breo

    Doubt: Why Quadratic in Matrix but Power 4 in Einstein-Rosen Metric?

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  19. Breo

    What is the Unique Metric Tensor in this Line Element?

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  20. P

    Israel Wilson Perjes Metric: Tetrad Formalism Reference

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  21. B

    Can g_00 of the metric tensor depend on time

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  22. M

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  23. Orion1

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  24. K

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  25. N

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  26. arpon

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  27. R

    How does one get time dilation, length contraction, and E=mc^2 from spacetime metric?

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  28. RCopernicus

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  29. stevendaryl

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  30. D

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  31. P

    Deriving Metric $$g_{ij}$$ w/ Respect to Time t

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  32. S

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  33. R

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  34. K

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  35. Ravi Mohan

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  36. S

    Temporal components in metric tensors

    As you may know, the metric tensor for 3D spherical coordinates is as follows: g11= 1 g22= r2 g33= r2sin2(θ) Now, the Minkowski metric tensor for spherical coordinates is this: g00= -1 g11= 1 g22= r2 g33= r2sin2(θ) In both of these metric tensors, all other elements are 0. Now...
  37. B

    Lorentz transformations and Minkowski metric

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  38. X

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  39. S

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    After my recent studies of the curvature of the 2- sphere, I would like to move on to Minkowski space. However, I can not seem to find the metric tensor of the 4 sphere on line, nor can I seem to think of the vector of transformation properties that I would use to derive the metric tensor of the...
  40. ChrisVer

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  41. B

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  42. S

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  43. ChrisVer

    Schwarz's Metric Gamma: Inertial Coordinates & Time Dilation

    Can the above logic be applied to Schw. Metric as well? Suppose I have an object moving with a radial velocity v=const, then can I do the same to derive the Schwarchild time dilation as in the Minkowski? dr = v ~ dt ds^{2} = [K - \frac{v^2}{K} ] dt^2 So \gamma ^{-1} = \sqrt{K} [1 -...
  44. shounakbhatta

    The question: What are the components of the gab metric in Kaluza-Klein theory?

    Hello, I am trying to understand Kaluza Klein theory on the five dimensional unification. It was mentioned over there: " Of the 15 components of gαβ, five had to get a new physical interpretation, i.e. gα5 and g55; the components gik, i,k = 1,...,4, were to describe the gravitational field...
  45. W

    What is a metric for uniformly moving frame?

    The Schwarzschild Metric has a form: ##ds^2 = Kdt^2 - 1/K dr^2 - r^2dO^2## where: K = 1 - a/r; There is a time scaled by K, but a space radially by 1/K. This is a typical time dilation and a space contraction, which is known from SR, but the Schwarzschild metrics is spherically...
  46. J

    Local Conformal Transformations:Coordinate or metric transformations?

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  47. M

    Confusion with Dot Product in Polar Coordinates with the Metric Tensor

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  48. ChrisVer

    Mass in Schwarzschild's Metric: Exploring Vacuum Solutions

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  49. Markus Hanke

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    In the Wiki article about the Vaidya metric : http://en.wikipedia.org/wiki/Vaidya_metric there is mention of a "further generalisation" called the Kinnersley metric, without giving any details or even a reference. Is this a generalisation of the Vaidya metric to include angular momentum (...
  50. grav-universe

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