2024-07-05-NSW6: Transect NSW Site 6, Landsat 9 and Sentinel-2B dual overpass

This is a report of the field data collected on 5 July 2024 at the location of Transect NSW Site 6 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

SR-3500_20680T1

Time of field site measurements (UTC)

2024-07-04 23:41:39 to 2024-07-05 00:38:22

Time of Landsat 9 overpass (UTC)

2024-07-04 23:54:33

Time of Sentinel-2B overpass (UTC)

2024-07-15 00:15:28

GPS quality

Good

Reference position

150.02628167E, 30.78772667S (WGS84)

Matchup quality for Landsat 9

Good

Matchup quality for Sentinel-2B

Excellent

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

0.019

0.004

0.033

0.007

blue

0.022

0.004

0.037

0.009

green

0.046

0.01

0.068

0.016

red

0.039

0.01

0.054

0.025

NIR

0.304

0.137

0.42

0.191

SWIR1

0.14

0.021

0.189

0.053

SWIR2

0.073

0.018

0.098

0.05

Results of Field data versus Sentinel-2B Satellite

Band

Sat Mean

Sat rms

Field mean

Field rms

CA

0.036

0.004

0.029

0.007

blue

0.036

0.005

0.035

0.008

green

0.057

0.01

0.064

0.016

red

0.044

0.014

0.048

0.024

RE1

0.09

0.014

0.107

0.027

RE2

0.295

0.138

0.337

0.158

RE3

0.339

0.164

0.393

0.189

NIR1

0.348

0.169

0.403

0.188

NIR2

0.362

0.165

0.409

0.186

SWIR2

0.152

0.02

0.183

0.051

SWIR3

0.076

0.021

0.093

0.047

Figures

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

../../../_images/RGB-2024-07-05-NSW6.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-2024-07-05-NSW6.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-2024-07-05-NSW6.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.