The Nobeyama 45-m Telescope (hereafter NRO45) is one of the largest millimeter radio telescope in the world. It has a Cassegrain-Coud´e optics. The paraboloidal main reflector consists of about 600 pieces of panels, each of which has a surface accuracy of about 60 microns, and the deviation of the whole antenna from an ideal paraboloid is about 90 microns. The sub-reflector has a diameter of 4 m with a convex hyperboloid surface, the position of which is computer-controlled to follow the moving focal point because the main reflector deforms as the elevation angle changes. The slewing speed of the telescope is 20◦/min (i.e., 0.3◦/sec). The (EL, AZ) driving ranges are also summarized in Table 2. More details on the NRO45 can be found in the Nobeyama Radio Observatory official website [2].
The aperture efficiency and beam size of the NRO45 at K- and Q-bands are listed in Table 3. The values for NRO45 are based on the latest measurements in autumn 2017, where the Jupiter or the Mars was used as a reference source. The elevation dependence of the aperture efficiency is approximately constant over a range of El ∼ 25◦ – 50◦ at both K- and Q-bands.
Site | East Longitude [◦ ′ ′′] |
North Latitude [◦ ′ ′′] |
Ellipsoidal Height [m] |
X [m] |
Y [m] |
Z [m] |
---|---|---|---|---|---|---|
Nobeyamaa | 138 28 21.2 | 35 56 40.9 | 1350 | -3871025.4987 | 3428107.3984 | 3724038.7361 |
Tianmab | 121 08 09.4 | 30 55 19.8 | 49.2 | -2826708.6380 | 4679237.0440 | 3274667.5330 |
Mizusawac | 141 07 57.3 | 39 08 00.7 | 116.4 | -3857244.6475 | 3108782.9982 | 4003899.2132 |
Irikic | 130 26 23.6 | 31 44 52.4 | 573.6 | -3521719.8292 | 4132174.6212 | 3336994.1399 |
Ogasawarac | 142 12 59.8- | 27 05 30.5 | 273.1 | -4491068.5584 | 3481545.0777 | 2887399.7419 |
Ishigakijimac | 124 10 15.6 | 24 24 43.8 | 65.1 | -3263995.1630 | 4808056.3180 | 2619948.7989 |
Yonseid | 126 56 27.4 | 37 33 54.9 | 139 | -3042280.9137 | 4045902.7164 | 3867374.3544 |
Ulsand | 129 14 59.3 | 35 32 44.2 | 170 | -3287268.6186 | 4023450.1799 | 3687380.0198 |
Tamnad | 126 27 34.4 | 33 17 20.9 | 452 | -3171731.5580 | 4292678.4878 | 3481038.7252 |
aThe position was measured in late 2016. bbThe epoch of the coordinate is January 01, 2014. cThe epoch of the coordinates is January, 01, 2015. dThe antenna positions are obtained by the KaVA K-band geodesy program on January 24, 2014. |
EAVN ( East Asia VLBI Network )