Sudan 1 | EROS CalVal Center of Excellence

EROS Cal/Val Center of Excellence (ECCOE)

Test Sites Catalog

Sudan 1

Landsat 8 LandsatLook Image Path 177 Row 45 Acquired 13 Aug 2020 with ROI indicated

Google Earth Image centered on Sudan ROI

Description

The Sudan 1 site is located in Sudan, Africa. The spatial homogeneity and temporal stability of this site meets the 3 percent threshold criteria to be considered invariant. Some seasonal variations of cloud cover do exist, but the magnitude of these variations is moderate, and this site can be used throughout the year [1]. There are dunes at detailed scale, but choppier and less linear than other North African desert sites. The pattern is somewhat patchy (in color and intensity) overall, but there are a few uniform patches of 10 x 10 kilometers (km).

Usability

Like other Pseudo Invariant Calibration Sites (PICS), Sudan 1 has greater importance in calibration stability monitoring. Cross-calibration of medium-resolution sensors have been performed using the Sudan 1 site [2]. Moreover, further research demonstrated the site’s importance in absolute calibration [3] and emphasized the stability of the site [4].

Location (City, State, Country):	Sudan, Africa
Landsat WRS - 2 Path / Row:	177/45
Center Latitude (degrees):	N 21.40
Center Longitude (degrees):	E 27.70
CNES Region of Interest	N 22.00, E 27.90 N 22.00, E 28.10 N 21.80, E 28.10 N 21.80 E 27.90 Search this area in EarthExplorer (Landsat 8-9 Collection 2 Level-1) - date range, datasets, cloud cover and other criteria can be modified once initial results are returned KML (Need help with this file?)
SDSU Region of Interest	N 21.75, E 27.59 N 21.75, E 27.81 N 21.40, E 27.81 N 21.40, E 27.59 Search this area in EarthExplorer (Landsat 8-9 Collection 2 Level-1) - date range, datasets, cloud cover and other criteria can be modified once initial results are returned KML (Need help with this file?)
Size of Usable Area (km):	10 x 10
UTM Zone:	35
Altitude above sea level (meters):	325
Purpose:	Radiometry
Status:	Active

References:

Cosnefroy, Helene, Marc Leroy, and Xavier Briottet. "Selection and characterization of Saharan and Arabian desert sites for the calibration of optical satellite sensors." Remote Sensing of Environment 58, no. 1 (1996): 101-114.
Chander, Gyanesh, Amit Angal, Taeyoung Choi, and Xiaoxiong Xiong. "Radiometric cross-calibration of EO-1 ALI with L7 ETM+ and Terra MODIS sensors using near-simultaneous desert observations." IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 6, no. 2 (2013): 386-399.
Raut, Bipin, Morakot Kaewmanee, Amit Angal, Xiaoxiong Xiong, and Dennis Helder. "Empirical Absolute Calibration Model for Multiple Pseudo-Invariant Calibration Sites." Remote Sensing 11, no. 9 (2019): 1105.
Tuli, Fatima Tuz Zafrin & Pinto, Cibele & Angal, Amit & Xiong, Xiaoxiong & Helder, Dennis. (2019). New Approach for Temporal Stability Evaluation of Pseudo-Invariant Calibration Sites (PICS). Remote Sensing. 11. 1502. 10.3390/rs11121502. 
Barsi, Julia A., Bahjat Alhammoud, Jeffrey Czapla-Myers, Ferran Gascon, Md Obaidul Haque, Morakot Kaewmanee, Larry Leigh, and Brian L. Markham. "Sentinel-2A MSI and Landsat-8 OLI radiometric cross comparison over desert sites." European Journal of Remote Sensing 51, no. 1 (2018): 822-837.

Note: This information has been compiled by the USGS ECCOE Team, using the best sources currently known. Updates will be made as more information becomes available. Please contact eccoe@usgs.gov with any updates you would like to contribute.