Crystal B. Schaaf

Prof. Crystal B. Schaaf


Research Focus & Metrics

Academic Career Length

40Years (1987-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2014 in Remote Sensing of Environment
Verified
Journal Article
Open access
DRD.P. Roy
D.P. Roy
MWMichael Wulder
Michael Wulder
TLT.R. Loveland
T.R. Loveland
WCWoodcock C.E.
Woodcock C.E.
RAR.G. Allen
R.G. Allen
Zhe ZhuZhe Zhu
Zhe Zhu
Landsat 8, a NASA and USGS collaboration, acquires global moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave, and thermal infrared. Landsat 8 extends the remarkable 40year Landsat record and has enhanced capabilities including new spectral bands in the blue and cirrus cloud-detection portion of the spectrum, two thermal bands, improved sensor signal-to-noise performance and associated improvements in radiometric resolution, and an improved duty cycle that allows collection of a significantly greater number of images per day. This paper introduces the current (2012–2017) Landsat Science Team's efforts to establish an initial understanding of Landsat 8 capabilities and the steps ahead in support of priorities identified by the team. Preliminary evaluation of Landsat 8 capabilities and identification of new science and applications opportunities are described with respect to calibration and radiometric characterization; surface reflectance; surface albedo; surface temperature, evapotranspiration and drought; agriculture; land cover, condition, disturbance and change; fresh and coastal water; and snow and ice. Insights into the development of derived ‘higher-level’ Landsat products are provided in recognition of the growing need for consistently processed, moderate spatial resolution, large area, long-term terrestrial data records for resource management and for climate and global change studies. The paper concludes with future prospects, emphasizing the opportunities for land imaging constellations by combining Landsat data with data collected from other international sensing systems, and consideration of successor Landsat mission requirements

1 November 2002 in Remote Sensing of Environment
Verified
Journal Article
Closed access
MFM.A Friedl
M.A Friedl
DMD.K McIver
D.K McIver
JHJ.C.F Hodges
J.C.F Hodges
XZX.Y Zhang
X.Y Zhang
DMD Muchoney
D Muchoney
CSCrystal B. Schaaf
Crystal B. Schaaf

1 November 2002 in Remote Sensing of Environment
Verified
Journal Article
Closed access
CSCrystal B. Schaaf
Crystal B. Schaaf
Feng GaoFeng Gao
Feng Gao
ASAlan H Strahler
Alan H Strahler
WLWolfgang Lucht
Wolfgang Lucht
XLXiaowen Li
Xiaowen Li
DRDavid Roy
David Roy

1 March 2003 in Remote Sensing of Environment
Verified
Journal Article
Closed access
XZXiaoyang Zhang
Xiaoyang Zhang
MFMark A. Friedl
Mark A. Friedl
CSCrystal B. Schaaf
Crystal B. Schaaf
ASAlan H. Strahler
Alan H. Strahler
JHJohn C.F. Hodges
John C.F. Hodges
Alfredo R HueteAlfredo R Huete
Alfredo R Huete

1 March 2000 in IEEE Transactions on Geoscience and Remote Sensing
Verified
Journal Article
Closed access
WLW. Lucht
W. Lucht
CSCrystal B. Schaaf
Crystal B. Schaaf
ASA.H. Strahler
A.H. Strahler
Spectral albedo may be derived from atmospherically corrected, cloud-cleared multiangular reflectance observations through the inversion of a bidirectional reflectance distribution function (BRDF) model and angular integration. This paper outlines an algorithm suitable for this task that makes use of kernel-based BRDF models. Intrinsic land surface albedos are derived, which may be used to derive actual albedo by taking into account the prevailing distribution of diffuse skylight. Spectral-to-broadband conversion is achieved using band-dependent weighting factors. The validation of a suitable BRDF model, the semiempirical Ross-Li (reciprocal RossThick-LiSparse) model and its performance under conditions of sparse angular sampling and noisy reflectances are discussed, showing that the retrievals obtained are generally reliable. The solar-zenith angle dependence of albedo may be parameterized by a simple polynomial that makes it unnecessary for the user to be familiar with the underlying BRDF model. The algorithm given is that used for the production of a BRDF/albedo standard data product from NASA's EOS-MODIS sensor, for which an at-launch status is provided. Finally, the algorithm is demonstrated on combined AVHRR and GOES observations acquired over New England, from which solar zenith angle-dependent albedo maps with a nominal spatial resolution of 1 km are derived in the visible band. The algorithm presented may be employed to derive albedo from space-based multiangular measurements and also serves as a guide for the use of the MODIS BRDF/albedo product.

1 June 2008 in Remote Sensing of Environment
Verified
Journal Article
Closed access
DRDavid Roy
David Roy
JJJunchang Ju
Junchang Ju
PLPHILIP EDWARD LEWIS
PHILIP EDWARD LEWIS
CSCrystal B. Schaaf
Crystal B. Schaaf
Feng GaoFeng Gao
Feng Gao
ELErik Lindquist
Erik Lindquist