calibration introduction of china land observation satellites

Calibration introduction of China land observation satellites

China Center for Resources Satellite Data and ApplicationMay 16, 2014

Pan Zhiqiang

1. Introduction1.1 CRESDA1.2 Land observation satellites of China

2. Calibration site2.1 Dunhuang gobi2.2 Qinghai lake2.3 Etuokeqi grassland2.4 Songshan stationary target

3. GF-1 on-orbit radiometric calibration3.1 site calibration3.2 cross-calibration

OUTLINE

1. Introduction

CRESDA(China Center for Resource Satellite Data and

Application) is the national center for data processing, archiving,

distributing and user service of land observation satellites developed

by China. It is responsible for many series satellite's operational

management, such as China-Brazil resources series satellite,

environment and disaster series satellite, high resolution series

satellite, mapping satellite, and so on.

1. Introduction

With more than 20 years’ development, CRESDA has been constantly improving its capability in satellite ground processing system construction, satellite operational management, satellite remote sensing data application technical research and development, and so on.

1. Introduction

CRESDA has successfully operated 11 satellites , including CBERS-01/02/02B,HJ-1A/1B/1C, ZY-1 02C ,ZY-3 and SJ-9A/B.Now,8 of these satellites are on orbit.

LAND RSSATELLITE

CBERS-01/02/02B

1999.10~2010.04

First land remote sensing satellite of China

SJ-9a/B

2012.10~now

2.5m PAN/10m MUX

GF-1

HJ-1A/B/c

2008.09~now HJ-1A/1BLarge swoth coverage, revisit time 2 days2012.11~now HJ-1C

SAR with 5m resolution

ZY-1 02C2011.12~now2.36m resolution 54km image width

ZY-3 2012.01~nowMapping satelliteDEM production

2013.4~now

GF-1 with 2m/8m resolution.

Satellite Payloadspatial

resolution(m)swath(km) 侧摆能力侧摆能力侧摆能力侧摆能力

Revisit time （（（（day））））

HJ-1ACCD 30 700

4HSI 100 50 ±30°

HJ-1BCCD 30 700IRS 150 720

HJ-1C SAR

5（Single vision，strip）

20（4visions，scan）

40（strip）

100（scan）

31°44.5° 4

ZY-1 02CHR 2.36

27（single）54（double）

±25º3～5

PMS5

60 ±32º10

ZY-3

FWD 3.552

±32° 3～5BWD 3.5NAD 2.1

51MUX 6 5

SJ-9APAN 2.5 30 ±35° 69MUX 10 30

SJ-9B TDI 73 18 ±15° 69

GF-1

PAN 2 60±25° 4

MUX 8 60

WFV 16 800 2

1. Introduction

2. Calibration site

2. Calibration site

2.1 Dunhuang gobi

actual view of Dunhuang Gobi

GF-1 image of Dunhuang

Dunhuang Test Site

N40.04 °~ 40.28 °E94.17 °~ 94.5 °

Area 60*40km2

Area: 400m2

Altitude:1229m

The site is constructed with black, gray and white gravel;atmospheric aerosol type : closer to the desert type;Air condition: clean , dry.

2. Calibration site

2.2 Qinghai lake

Qinghai Lake Test Site

Area: 4473km2

Perimeter: 360kmmaximum depth:38maverage elevation:3.196km

36°41'N~36°45'N，100°22'E~100°30'E

high altitudelow aerosol particlescontinental aerosol typeuniform surface temperature

2. Calibration site

2.3 Etuokeqi grassland-SAR calibration

Ground type is mainly made up of grasslands and sandy loam, which has lower scatter properties and relatively stable. Distance range and azimuth range is greater than 100km and 30km respectively, with an area of 130km× 40km. Noise ratio between the calibration reference and background clutter signal is less than 30dB. Topography of the site is less than 20 meters.

2. Calibration site

2.4 Songshan stationary target

For radiation calibration, there are fan- resolution target, blade edge target, a large area of gray target and point source matrix et al.

2. Calibration site

2.4 Songshan stationary target

For geometry calibration, there are two straight lines from the east to west, with the artificial signs in black and white diagonal cross pattern.

3. GF-1 on-orbit radiometric calibration

3.1 site calibration

high reflectance(40%)

gypsum crystal

(6600mx5000m)

Middle reflectance(20%)

gobi(550mx550m)

low reflectance(<10%)

water(2500mx500m)

3. GF-1 on-orbit radiometric calibration

3.1 site calibration

�Dunhuang calibration site- data measurement

�atmospheric parameter - aerosol

�ground parameter -surface reflectance

3. GF-1 on-orbit radiometric calibration

3. GF-1 on-orbit radiometric calibration

3. GF-1 on-orbit radiometric calibration

3.2 cross-calibration

Target sensor

4 Wide Field of View (WFV)

Spatial resolution 16m

Swath 830km

3. GF-1 on-orbit radiometric calibration

3.2 cross-calibration

Reference sensor

VelocityVector

• OBCs: SD/SDSM, BB, SRCA, SV• Lunar observations

SDSM

Scan Mirror

SolarDiffuser

SRCA

Blackbody

SpaceView

3. GF-1 on-orbit radiometric calibration

3.2 cross-calibration

3. GF-1 on-orbit radiometric calibration

3.2 cross-calibration

3. GF-1 on-orbit radiometric calibration

3.2 cross-calibration

201306~201402

26 pairs

16pairs

Cloud

9pairs

3. GF-1 on-orbit radiometric calibration

3.2 cross-calibration

3. GF-1 on-orbit radiometric calibration

3.2 cross-calibration

errorBlue Green Red Near-infrared

number percent number percent number percent number percent

>10% 1 11.1% 0 0% 0 0% 0 0%

5-10% 5 55.6% 1 11.1% 1 11.1% 1 11.1%

<5% 3 33.3% 8 88.9% 8 88.9% 8 88.9%

谢谢谢谢谢谢谢谢!Thank you !