LRO Pointing Allocations Stephen Andrews Code 595 August 16-17, 2005

Introduction some data products and instruments drive knowledge, some drive accuracy instruments on spacecraft bus have different allocations than instruments on instrument module pointing allocations will be shown for each of the LRO Instruments the mini-RF the High Gain Antenna System the Solar Array System

Notes All values are 3-sigma, zero (or mean) to peak Allocations derived so that if allocations are met, requirements will be met Considering rotational errors only; no orbit (translation) errors included Difference between knowledge and accuracy is ACS control error

CRaTER Knowledge Allocation = 7.42 deg CRaTER knowledge requirement = 10 degrees two-axis RSS

CRaTER Accuracy Allocation = 7.44 deg CRaTER accuracy requirement = 35 degrees two-axis RSS

Diviner Knowledge Allocation Diviner spacecraft knowledge requirement = 3000 microrad = 619 asec

Diviner Accuracy Allocation Diviner spacecraft accuracy requirement = 6000 microrad = 1238 asec

LAMP Knowledge Allocation LAMP knowledge desired = 0.2 pixel = 0.06 deg = 216 asec

LAMP Accuracy Allocation LAMP accuracy requirement = 0.15 deg = 540 asec

LEND Knowledge Allocation LEND knowledge requirement = 0.1 deg = 360 asec

LEND Accuracy Allocation LEND accuracy requirement = 0.1 deg = 360 asec

LOLA Knowledge Allocation LOLA knowledge requirement = TBD asec

LOLA Accuracy Allocation LOLA accuracy requirement = 1 deg = 3600 asec

LROC NAC Knowledge Allocation LROC NAC knowledge requirement = TBD asec

LROC NAC Accuracy Allocation LROC NAC accuracy requirement = TBD asec

LROC NAC Coalignment Allocation LROC NAC coalignment accuracy requirement = TBD asec

LROC WAC Knowledge Allocation LROC WAC knowledge requirement = TBD asec

LROC WAC Accuracy Allocation LROC WAC accuracy requirement = TBD asec

Mini-RF Knowledge Allocation Mini-RF knowledge requirement = TBD asec

Mini-RF Accuracy Allocation Mini-RF accuracy requirement = TBD asec

HGA Pointing Accuracy Allocation HGA pointing accuracy requirement = 0.3 deg

HGA Pointing Accuracy Notes Known bias errors assumed measurable/predictable, removable by compensation. Ground-to-orbit bias errors can be measured and corrected after on-orbit deployment. Assumes a calibration is done right after ephemeris upload. Single calibration done to remove thermal distortion bias. Random/ground to orbit column total is analytical calibration residual error.

SA Pointing Accuracy Allocation SA pointing accuracy requirement = 5 deg

SA Pointing Accuracy Notes Known bias errors assumed measurable/predictable, removable by compensation. Ground-to-orbit bias errors can be measured and corrected after on-orbit deployment No calibration needed.

Conclusion Pointing allocations understood Thermal distortions will vary from component to component Allocations meet component requirements