Leonardo spaceborne infrared payloads for Earth observation: SLSTRs for Copernicus Sentinel 3 and PRISMA hyperspectral camera for PRISMA satellite
Peter Coppo, Fabio Brandani, Marco Faraci, Francesco Sarti, Michele Dami, Leandro Chiarantini, Beatrice Ponticelli, Lorenzo Giunti, Enrico Fossati, and Massimo Cosi
Peter Coppo,*
Fabio Brandani,
Marco Faraci,
Francesco Sarti,
Michele Dami,
Leandro Chiarantini,
Beatrice Ponticelli,
Lorenzo Giunti,
Enrico Fossati,
and Massimo Cosi
Leonardo, Via delle Officine Galileo, 1, 50013 Campi Bisenzio, Florence, Italy
Peter Coppo, Fabio Brandani, Marco Faraci, Francesco Sarti, Michele Dami, Leandro Chiarantini, Beatrice Ponticelli, Lorenzo Giunti, Enrico Fossati, and Massimo Cosi, "Leonardo spaceborne infrared payloads for Earth observation: SLSTRs for Copernicus Sentinel 3 and PRISMA hyperspectral camera for PRISMA satellite," Appl. Opt. 59, 6888-6901 (2020)
Leonardo has been involved in the realization of several infrared payloads for Earth observation since 1990. Among the currently in-orbit operative instruments are the two Sea and Land Surface Temperature Radiometers (SLSTRs) and PRISMA (PRecursore IperSpettrale della Missione Applicativa, meaning Hyperspectral Italian Pre-cursor of Operational mission). The SLSTRs are high-accuracy radiometers that provide sea surface temperature data continuity with respect to previous (A)ATSRs in order to serve climatology over the next 20 years, and exist within the framework of the European Space Agency Sentinel-3 mission, which is part of the Copernicus program. The PRISMA program is the first Agenzia Spaziale Italiana optical hyperspectral mission for Earth observation. It is based on a high spectral resolution spectrometer operating in the visible-short wave infrared channels optically integrated with a panchromatic camera.
David Morales-Norato, Sergio Urrea, Hans Garcia, Julian Rodriguez-Ferreira, Elizabeth Martinez, Henry Arguello, Alberto Silva-Lora, Rafael Torres, Ignacio F. Acero, Francisco L. Hernández, Lorena P. Cárdenas, and Sonia Rincón Appl. Opt. 62(8) C88-C98 (2023)
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NeDT In-flight Performance Evaluated by Looking at the Two Blackbodies for Models S3A and S3Ba
S3A
S3A
S3B
S3B
Mathematical Model BOL-EOL
EOL Requirement Goal-Threshold
Tscene
267 K
304 K
267 K
304 K
270 K (F1 = 350 K, F2 = 330 K)
300 K
270 K
S7
47 mK
17 mK
42 mK
16 mK
51–56 mK
22–24 mK
50–80 mK
S8
14 mK
11 mK
17 mK
13 mK
19–21 mK
15–16 mK
30–50 mK
S9
22 mK
18 mK
18 mK
14 mK
20–24 mK
17–19 mK
30–50 mK
F1
1.1 K
0.266 K
1.5 K
0.364 K
85–95 mK
0.377–0.42 K
1 K (350–500 K)
F2
28 mK
36 mK
31 mK
30 mK
30–33 mK
35–38 mK
0.5 K (330–400 K)
Noise equivalent differential temperature (NeDT) is the input brightness temperature variation corresponding to an instrument SNR equal 1 (at 1 $\sigma$ of standard deviation). Compliant means NedT performance less than requirement; (Cycle 052 and 033: both views in [6, 7]) compared with begin of life (BOL), end of life (EOL) mathematical model and instrument requirements.
Table 2.
SNR (at 1 standard deviation) In-flight Performance Evaluated by Looking at the Visible Calibration (VISCAL) Unit for Models S3A and S3Ba
The reference radiance for each channel (${{{L}}_{\text{VISCAL}}}$) is obtained by means of the following equation: ${{{L}}_{\text{VISCAL}}} = {{\text{BRDF}}_{\text{VISCAL}}}\;*$${{{I}}_{\text{SUN}}}$, with ${{\text{BRDF}}_{\text{VISCAL}}} = {\rho _{\text{VISCAL}}}/\pi$ the VISCAL bidirectional reflectance distribution function (BRDF), ${\rho _{\text{VISCAL}}}$ the VISCAL reflection factor, and ${{{I}}_{\text{SUN}}}$ the top of atmosphere (TOA) sun irradiance. By defining the sun radiance (${{{L}}_{\text{SUN}}}$) from an ideal Lambertian diffuser illuminated with the TOA sun irradiance with the equation ${{{L}}_{\text{SUN}}} = {{{I}}_{\text{SUN}}}/\pi$, it is possible to obtain the following simplified relationship: ${{{L}}_{\text{VISCAL}}} = {\rho _{\text{VISCAL}}}\;*{{{L}}_{\text{SUN}}}$. The S4-S5-S6 SNR performance represents the average value between all measured detector pixels multiplying for a ${\sqrt 2}$ factor, due to the double sampling achieved with the two column pixels. Comparison between requirements and performance are reported in the last three columns. Compliant means SNR performance higher than requirement. (Cycle 052 and 033 nadir view in [7].)
Value of RFW approved by the agency.
Table 3.
PRISMA Performance Compared with Requirements (V Column Reports the Verification Method for Each Performance: F = in Flight, G = on Ground, NA = Not Applicable)
Value of the RFW approved by the agency.
Compliance of absolute radiometric accuracy has been verified after the submission of this paper and detailed results will be reported in a new dedicated paper.
Tables (3)
Table 1.
NeDT In-flight Performance Evaluated by Looking at the Two Blackbodies for Models S3A and S3Ba
S3A
S3A
S3B
S3B
Mathematical Model BOL-EOL
EOL Requirement Goal-Threshold
Tscene
267 K
304 K
267 K
304 K
270 K (F1 = 350 K, F2 = 330 K)
300 K
270 K
S7
47 mK
17 mK
42 mK
16 mK
51–56 mK
22–24 mK
50–80 mK
S8
14 mK
11 mK
17 mK
13 mK
19–21 mK
15–16 mK
30–50 mK
S9
22 mK
18 mK
18 mK
14 mK
20–24 mK
17–19 mK
30–50 mK
F1
1.1 K
0.266 K
1.5 K
0.364 K
85–95 mK
0.377–0.42 K
1 K (350–500 K)
F2
28 mK
36 mK
31 mK
30 mK
30–33 mK
35–38 mK
0.5 K (330–400 K)
Noise equivalent differential temperature (NeDT) is the input brightness temperature variation corresponding to an instrument SNR equal 1 (at 1 $\sigma$ of standard deviation). Compliant means NedT performance less than requirement; (Cycle 052 and 033: both views in [6, 7]) compared with begin of life (BOL), end of life (EOL) mathematical model and instrument requirements.
Table 2.
SNR (at 1 standard deviation) In-flight Performance Evaluated by Looking at the Visible Calibration (VISCAL) Unit for Models S3A and S3Ba
The reference radiance for each channel (${{{L}}_{\text{VISCAL}}}$) is obtained by means of the following equation: ${{{L}}_{\text{VISCAL}}} = {{\text{BRDF}}_{\text{VISCAL}}}\;*$${{{I}}_{\text{SUN}}}$, with ${{\text{BRDF}}_{\text{VISCAL}}} = {\rho _{\text{VISCAL}}}/\pi$ the VISCAL bidirectional reflectance distribution function (BRDF), ${\rho _{\text{VISCAL}}}$ the VISCAL reflection factor, and ${{{I}}_{\text{SUN}}}$ the top of atmosphere (TOA) sun irradiance. By defining the sun radiance (${{{L}}_{\text{SUN}}}$) from an ideal Lambertian diffuser illuminated with the TOA sun irradiance with the equation ${{{L}}_{\text{SUN}}} = {{{I}}_{\text{SUN}}}/\pi$, it is possible to obtain the following simplified relationship: ${{{L}}_{\text{VISCAL}}} = {\rho _{\text{VISCAL}}}\;*{{{L}}_{\text{SUN}}}$. The S4-S5-S6 SNR performance represents the average value between all measured detector pixels multiplying for a ${\sqrt 2}$ factor, due to the double sampling achieved with the two column pixels. Comparison between requirements and performance are reported in the last three columns. Compliant means SNR performance higher than requirement. (Cycle 052 and 033 nadir view in [7].)
Value of RFW approved by the agency.
Table 3.
PRISMA Performance Compared with Requirements (V Column Reports the Verification Method for Each Performance: F = in Flight, G = on Ground, NA = Not Applicable)
Value of the RFW approved by the agency.
Compliance of absolute radiometric accuracy has been verified after the submission of this paper and detailed results will be reported in a new dedicated paper.