2023-11-27-NSW1: Transect NSW Site 1, Landsat 9 and Sentinel-2B dual overpass

This is a report of the field data collected on 27 November 2023 at the location of Transect NSW Site 1 to validate the satellite data of the Landsat 9 and Sentinel-2B dual overpass. The full collection of data is contained in the National Spectral Database. Satellite data can be found on DEA maps.

Variables

These variables and environmental factors were present on the day the data were collected.

Instrument(s) used

ASD FR4 (18179/3)

Time of field site measurements (UTC)

2023-11-26 22:37:46 to 2023-11-26 23:37:06

Time of Landsat 9 overpass (UTC)

2023-11-27 00:26:53

Time of Sentinel-2B overpass (UTC)

2023-12-07 00:45:52

GPS quality

Good

Reference position

142.1036962E, 31.8135401S (WGS84)

Matchup quality for Landsat 9

Good

Matchup quality for Sentinel-2B

Good

Results

The surface reflectance statistics collected on this day are grouped into bands. This allows the data to be used to validate Geoscience Australia’s other datasets that use the same standardised bands.

Results of Field data versus Landsat 9 Satellite

Band

Sat Mean

Sat rms

Field mean

Field rms

CA

0.072

0.01

0.048

0.003

blue

0.082

0.009

0.06

0.004

green

0.122

0.007

0.105

0.011

red

0.197

0.011

0.18

0.028

NIR

0.27

0.011

0.248

0.03

SWIR1

0.407

0.011

0.389

0.038

SWIR2

0.321

0.012

0.314

0.039

Results of Field data versus Sentinel-2B Satellite

Band

Sat Mean

Sat rms

Field mean

Field rms

CA

0.055

0.0

0.049

0.003

blue

0.066

0.001

0.064

0.004

green

0.102

0.005

0.104

0.01

red

0.185

0.014

0.188

0.028

RE1

0.208

0.014

0.209

0.031

RE2

0.224

0.015

0.225

0.033

RE3

0.234

0.015

0.237

0.033

NIR1

0.244

0.015

0.246

0.031

NIR2

0.25

0.012

0.251

0.03

SWIR2

0.387

0.011

0.395

0.038

SWIR3

0.307

0.012

0.322

0.039

Figures

The following figures provide visual representations of the data. (Click a figure to view it at full size.)

../../../_images/RGB-2023-11-27-NSW1.png

Satellite imagery tiles of true colour (RGB) surface reflectance. They each cover an area of approximately 2 km × 2 km. The white box indicates the size and location of the field site.

../../../_images/SiteComparison-2023-11-27-NSW1.png

Band-by-band plots of surface reflectance for field data versus each satellite. Satellite uncertainty error bars for each band are the standard deviation of pixel values over and surrounding the field site. Field uncertainty error bars are the standard deviation of values after averaging all spectra within the same satellite pixels.

../../../_images/OverallComparison-2023-11-27-NSW1.png

Plots of Satellite Surface Reflectance for each satellite versus Field Site Surface Reflectance on this day. The solid line represents the one-to-one equality between field and satellite measurements. The black dots are the values from all field site measurements prior to this date. The line of best fit is not shown, but its parameters are given in the bottom-right corner.