Technical Specifications

This page summarizes the NGPS technical specifications from the May 14, 2026 Version 2 specification sheet.

General Specifications

Category

Specification

Instrument type

4-channel UV-NIR spectrograph

Wavelength coverage

3050 to 10400

Telescope focus

Cassegrain focus at P200, F/13.6, 2.54 arcsec/mm

Slit / IFU

3-slit adjustable-width IFU

Slice length

50 arcsec long

Slice width

0.36 to 10 arcsec wide per slice

Spectral resolution

R > 4000 for the narrowest slit setting

Exposure timing

Common exposure time

Detector binning

Independently binned spatial and spectral directions

Readout mode

BOI mode

Channel Performance

Channel

Bandpass

Max Efficiency, Slit

Spectral Resolution at 0.4 arcsec

Spatial Resolution

U

3050 to 4430

65%

4100

Seeing limited

G

4250 to 5960

60%

4200

Seeing limited

R

5620 to 7950

74%

4300

Seeing limited

I

7530 to 10400

74%

4500

Seeing limited

Detector and Readout Properties

Channel

Plate Scale (arcsec/pixel)

Dispersion (A/pixel)

Read Noise (e rms)

Dark Current (e/pixel/hour)

U

0.193

0.340

2.8

< 5.6 TBC

G

0.189

0.435

7.8

< 1.7

R

0.186

0.577

3.7

< 1.2

I

0.186

0.713

4.6

< 1.0

Detector Format and Cosmic-Ray Rate

Channel

Active Detector Region

Pixel Size

Cosmic-Ray Rate (% pixel/hour)

2x1 Bin Readout Time (s)

U

1024 x 4102

15 um square pixels

1.1

64

G

1020 x 4114

15 um square pixels

2.8

31

R

1020 x 4114

15 um square pixels

3.2

55

I

1020 x 4114

15 um square pixels

2.1

55

Calibration System

Area

Specification

Calibration input

Telescope-mimicking f/14 telecentric input beam

Arc lamps

ThAr, FeAr

Continuum sources

Quartz halogen continuum, red; laser-pumped continuum, blue

Additional calibration sources

UV LEDs, etalon spectra

Calibration control

Concurrent calibration, individual lamp shutters, mechanical PWM control

Dome lamps

Palomar dome lamps: low, high, ultrahigh, He

Acquisition and Guidance

Area

Specification

Acquisition and guidance system

Offset guider

Field of view

4.44 x 4.15

Pixel scale

0.26 arcsec/pixel

Astrometry

Full-field solution

Filters

Photometric filters: g’, r’, i’, clear

Camera mode

EMCCD mode

Slice Viewing Cameras

Area

Specification

Configuration

Two fields of view adjacent to outer slices

Field of view

21 x 50 arcsec each

Pixel scale

0.060 arcsec/pixel

Additional Features

Feature

Exposure time calculator

Automated target acquisition

Guided afternoon calibration

Quick-look pipeline

Flexure compensation

Focus compensation

Observation Timeline Modeler (OTM)

Automatic binning adjustment

Frame transfer capability