# TRAO 2021 - 2022 Season Call for Proposal

The next deadline for proposals is 23:59 KST on 2021 August 10.

Proposals should be emailed as a single file in PDF format to:

traoprop@kasi.re.kr

The Korea Astronomy and Space Science Institute (KASI) invites proposals for the Taeduk Radio Astronomy Observatory (TRAO) 14-meter telescope for the 2021 Fall - 2022 Spring season. Proposal candidates should submit up to three pages of scientific and technical justifications (including figures, tables, and references) in addition to their Proposal Cover Sheet in English using the latex templates (form here):

There are two categories of proposals for the 2021-2022 observing season.

1. General Program (GP): single-year observing program with a telescope time of up to 300 hours
2. Key Science Program (KSP): multi-year observing program with a telescope time of 400 hours per year, for up to three years

TRAO supports multi-beam spectroscopy observations (4 x 4 array: SEQUOIA-TRAO) at a frequency range of 85 - 115.6 GHz. The TRAO system supports single-sideband observations for position-switched or OTF observations. The backend has two spectral windows controlled independently, each window with 4096 channels in a 62.5 MHz bandwidth. In addition, a single-pixel wide-band (2 GHz) spectrometer is available. Proposal candidates should consult the TRAO Status Report for additional technical specifications:

TRAO has a shared-risk remote observing mode available. However, inexperienced users are advised to do the observations on the site. Outside (non-KASI) PIs who intend to use the remote observing mode should specify local collaborators in the proposal. The local collaborators are responsible for handling on-site tasks during the remote observations, such as resetting the system in case of system failure, which happens occasionally.

TRAO, KASI

1. TRAO's multi-beam receiver system (SEQUOIA-TRAO) is a cryogenic focal plane array equipped with 16 high-performing InP MMIC amplifiers. The receiver temperature ranges from 60 ~ 80 K for 86 to 110 GHz, and 80 ~ 110 K for 115 GHz, and the system temperature ranges from about 200 K for 86 to 110 GHz, and 400 K for 115 GHz.
2. Two bedrooms and a fully equipped kitchen are available for on-site observers from outside. See https://radio.kasi.re.kr/trao/lodging.php for details.

### Beam parameters

Frequency ~ (GHz) ΘB('') ηA ~ (%) ηB ~ (%)
86.243 60 39 ± 2 46 ± 2
98.000 53 44 ± 1 52 ± 1
110.201 47 46 ± 1 54 ± 1
115.271 45 43 ± 2 51 ± 2

These parameters will be updated in Dec. 2016, further observations will be made in order to find details for new TRAO receiver systems. Beam sizes are calibrated with 86 GHz Rleo and Orion continuum data. Aperture and Beam efficiencies are measured from Venus and Jupiter continuum data observed at March 2016.

### OTF time estimation

#### Equation of RMS temperature

$\dpi{100}\bg_white T_{rms}=\frac{T_{sys}}{\eta_{spec}\times\sqrt{\Delta\nu\times (t_{\textrm{on}} + t_{\textrm{ref}})}}\times \Biggl[1+\frac{1}{\sqrt{N}}\Biggr]$

where,

• $\dpi{100}\bg_white T_{sys}:~500~\textrm{K}~at~115~\textrm{GHz},~300~\textrm{K}~at~110~\textrm{GHz},~200~\textrm{K}~at~86~\textrm{GHz}$
• $\dpi{100}\bg_white \eta_{spec}:~\sim 0.5~for~16~\textrm{beams}$
• $\dpi{100}\bg_white \Delta\nu:~15.3\times10^3~\textrm{(Hz)} \ ( \ \approx 62.5 \ MHz/4096 \ chs; \ fixed \ )$
• $\dpi{100}\bg_white t_{\textrm{on}}~=~X_{\textrm{length}}/\textrm{HPBW} \times t_{\textrm{samp}} \times X_{\textrm{step}} \times 16$   ( exposure time for source position )
• $\dpi{100}\bg_white t_{\textrm{ref}}~=~\sqrt{X_{\textrm{length}}\times N_{\textrm{ScanPerCal}}/\textrm{HPBW}}~ \times t_{\textrm{samp}}/2$   ( minimum required integration time on refence position )
• $\dpi{100}\bg_white X_{\textrm{ramp}}~=~\frac{X_{\textrm{step}}}{t_{\textrm{samp}}} \times 3$   ( 3 sec are required in order to get proper scan velocity )
• $\dpi{100}\bg_white N~=~X_{\textrm{length}}/\textrm{HPBW}$
• $\dpi{100}\bg_white T_{rms,final}~=~T_{rms}/\sqrt{\alpha}$   ( α: Scan iteration number in the same area )

### Example 1:

HPBW = 44", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.25 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 500 K, Cell size = 30"
map size time estimation raw data size (LO1+LO2) commant
6' × 6' > 30 min ~ 0.9 GB minimum size for OTF
10' × 10' > 47 min ~ 1.7 GB Trms ~ 0.7 K
12' × 12' > 57 min ~ 2.2 GB
15' × 15' > 73 min ~ 3.0 GB

Note. Overhead time will be varied upon your reference position. Cell size means the regridded pixel size of output data using OTFtools for CLASS and FITS files.

### Example 2:

HPBW = 44", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.75 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 500 K, Cell size = 30"
map size time estimation raw data size (LO1+LO2) commant
6' × 6' > 10 min ~ 0.3 GB minimum size for OTF
10' × 10' > 16 min ~ 0.6 GB Trms ~ 1.2 K
12' × 12' > 19 min ~ 0.8 GB
15' × 15' > 25 min ~ 1.0 GB

### Example 3:

HPBW = 22", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.25 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 500 K, Cell size = 30"
map size time estimation raw data size (LO1+LO2) commant
6' × 6' > 57 min ~ 2.2 GB minimum size for OTF
10' × 10' > 105 min ~ 4.8 GB Trms ~ 0.35 K
12' × 12' > 132 min ~ 6.3 GB

### Example 4:

HPBW = 22", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.75 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 500 K, Cell size = 30"
map size time estimation raw data size (LO1+LO2) commant
6' × 6' > 19 min ~ 0.8 GB minimum size for OTF
10' × 10' > 36 min ~ 1.6 GB Trms ~ 0.6 K
12' × 12' > 45 min ~ 2.2 GB
15' × 15' > 61 min ~ 3.2 GB