No abstract

No abstract

ABSTRACT:NASADEM is a near-global elevation model that is being produced primarily by completely reprocessing the Shuttle Radar Topography Mission (SRTM) radar data and then merging it with refined ASTER GDEM elevations. The new and improved SRTM elevations in NASADEM result from better vertical control of each SRTM data swath via reference to ICESat elevations and from SRTM void reductions using advanced interferometric unwrapping algorithms. Remnant voids will be filled primarily by GDEM3, but with reduction of GDEM glitches (mostly related to clouds) and therefore with only minor need for secondary sources of fill.

B ar c el o n a, S p ai n (e-m ail: f vi c e nt e @ d ar es.t e c h; j d ur o @ d ar es.t e c h). C. L o p e z-M arti n e z a n d J. J. M all or q uí Fr a n q u et ar e wit h t h e Si g n al T h e or y a n d C o m m u ni c ati o n D e p art m e nt, U ni v ersit at P olit é c ni c a d e C at al u n y a, 0 8 0 3 4 B ar c el o n a, S p ai n (e-m ail: c arl os.l o p e z @ts c. u p c. e d u; m all or q ui @ts c. u p c. es). J. M. L o p e z-S a n c h e z a n d A. M estr e-Q u er e d a ar e wit h t h e D e p art m e nt of P h ysi cs, S yst e m E n gi n e eri n g, a n d Si g n al T h e or y, U ni v ersit y of Ali c a nt e, 0 3 6 9 0 Ali c a nt e, S p ai n (e-m ail: j u a n m a.l o p e z @ u a. es; al ej a n dr o. m estr e @ u a. es). D. Zi ół k o ws ki is wit h t h e I nstit ut e of G e o d es y a n d C art o gr a p h y, 0 2-6 7 9 Wars a w, P ol a n d (e-m ail: D ari us z. Zi ol k o ws ki @i gi k. e d u. pl). M. L a v all e is wit h t h e J et Pr o p ulsi o n L a b or at or y, C alif or ni a I nstit ut e of Te c h n ol o g y, P as a d e n a, C A 9 1 1 0 9 U S A (e-m ail: m ar c o.l a v all e @j pl. n as a. g o v). G. S ur es h is wit h t h e F e d er al A g e n c y f or C art o gr a p h y a n d G e o d es y, 6 0 5 9 8 Fr a n kf urt a m M ai n, G er m a n y (e-m ail: g o pi k a 7 7 8 7 @ g m ail. c o m). O. A ntr o p o v is wit h t h e V T T Te c h ni c al R es e ar c h C e ntr e of Fi nl a n d, 0 2 0 4 4 Es p o o, Fi nl a n d (e-m ail: ol e g. a ntr o p o v @ vtt. fi). S. G e is wit h t h e S c h o ol of El e ctr o ni c a n d O pti c al E n gi n e eri n g, N a nji n g U ni v ersit y of S ci e n c e a n d Te c h n ol o g y, N a nji n g, C hi n a (e-m ail: g es h a oji a @ nj ust. e d u. c n). J. Pr a ks is wit h t h e D e p art m e nt of El e ctr o ni cs a n d N a n o e n gi n e eri n g, S c h o ol of El e ctri c al E n gi n e eri n g, A alt o U ni v ersit y, 0 2 1 5 0 H elsi n ki, Fi nl a n d (e-m ail: j a a n. pr a ks @ a alt o. fi). Y. B a n is wit h t h e Di visi o n of G e oi nf or m ati cs, D e p art m e nt f or Ur b a n Pl a nni n g a n d E n vir o n m e nt, K T H R o y al I nstit ut e of Te c h n ol o g y, 1 1 4 2 8 St o c k h ol m, S w e d e n (e-m ail: yif a n g @ kt h.s e). E. P otti er is wit h t h e I nstit ut d' El e ctr o ni q u e et d e T él e c o m m u ni c ati o ns d e R e n n es, U ni v ersit e d e R e n n es 1, 3 5 0 0 0 R e n n es, Fr a n c e (e-m ail: eri c. p otti er @ u ni v-r e n n es 1.fr). M. E. E n g d a hl is wit h t h e E ur o p e a n S p a c e R es e ar c h I nstit ut e, E ur o p e a n S p a c e A g e n c y, 0 0 0 4 4 Fr as c ati, It al y (e-m ail: m ar c us. e n g d a hl @ es a.i nt). Di git al O bj e ct I d e nti fi er 1 0.

ABSTRACT:NASADEM is a near-global elevation model that is being produced primarily by completely reprocessing the Shuttle Radar Topography Mission (SRTM) radar data and then merging it with refined ASTER GDEM elevations. The new and improved SRTM elevations in NASADEM result from better vertical control of each SRTM data swath via reference to ICESat elevations and from SRTM void reductions using advanced interferometric unwrapping algorithms. Remnant voids will be filled primarily by GDEM3, but with reduction of GDEM glitches (mostly related to clouds) and therefore with only minor need for secondary sources of fill.

No abstract

We present an empirical assessment of the impact of temporal decorrelation on interferometric coherence measured over a forested landscape. A series of repeat-pass interferometric radar images with a zero spatial baseline were collected with UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar), a fully polarimetric airborne L-band radar system. The dataset provided temporal separations of 45 minutes, 2, 7 and 9 days. Coincident airborne lidar and weather data were collected. We theoretically demonstrate that UAVSAR measurement accuracy enables accurate quantification of temporal decorrelation. Data analysis revealed precipitation events to be the main driver of temporal decorrelation over the acquisition period. The experiment also shows temporal decorrelation increases with canopy height, and this pattern was found consistent across forest types and polarization

No abstract