##### 

1)  
2)  
3)  
4)  

##### 

# 

1.  
2.  
3.  
4.  
5.  
6.  
7.  
8.  
9.  
10. 

##### 

[Calibration of NIS data]{.underline}

Calibration of NIS data follows a standard step-wise process originally
defined in Warren *et al.* (1997) and modified by experience with
in-flight data. The calibration pathway follows photons in reverse from
the detector to the source of reflected light (*e.g.*, a geologic
surface or caltarget).

The calibration equation for converting raw spectral signal in counts or
data numbers (DN) to physical units of radiance (W m^-2^ sr^-1^ µm^-1^)
has the form:

$$\text{Radiance}_{\lambda,t} = \frac{\left\{ \left\lbrack \frac{\text{DN}_{\lambda,t,T,M,s,i}}{\text{Obs}} - \text{Dark}_{\lambda\text{, t},T} \right\rbrack - \text{Xtalk}_{\lambda} \right\} \cdot \text{Mir}_{\lambda\text{,M},s} \cdot \text{Phot}_{\lambda\text{,i}} \cdot \text{Resp}_{\lambda\text{,s}} \cdot \text{Pol}_{\text{mir}} \cdot \text{Ecor}}{\text{Gain}_{\lambda}}$$

The variables are defined below, and their values are given in
appendices A and B.

  ------------------ --------------------------------------------------------------
  DN*~,t,T,M,s,i~*   Raw analog-to-digital count level at each detector channel of
                     wavelength at time *t*

  Obs                number of one-second observations summed to make a single
                     spectral measurement

  Dark*~,t,T~*       one-second detector dark signal, at time *t* close to the time
                     of the data spectra, including possible bias induced by
                     instrument temperature *T*

  Gain               corrects high-gain (10x) Germanium channel data to low (1x)

  Xtalk              correction applied to the first five Ge channels from second
                     order light

  Mir*~,M,s~*        correction factor for scan-mirror position *M* at slit
                     position *s*

  Phot*~,i~*         photometric correction for caltarget observations only at
                     solar illumination angle *I*

  Resp*~,s~*         per-channel DN-to-radiance conversion factor determined on the
                     ground using slit *s* (narrow or wide)

  Pol*~mt~*        change in detector response due to polarization effect on some
                     mirror positions.

  Ecor               Empirical correction to remove nonvariant high-frequency noise
                     in spectrum
  ------------------ --------------------------------------------------------------

Izenberg et al., 2000 (see Table IV) detail the evaluation of variables
used in the NIS calibration, from ground tests and operations in space.
More details on the ground calibrations are presented in Warren *et al.*
(1997).

The following table outlines the NIS calibration process, and lists
possible sources and effects of errors. The steps in the pathway are
discussed in the following sections.

NIS Calibration Pathway

+-----------------+-------------+------------+-------------+----------+
| ### Step        | ##          | #          | ### E       | ### Ef   |
|                 | # Variables | ## Output  | rror source | fect of  |
|                 |             |            |             | Error^1^ |
+-----------------+-------------+------------+-------------+----------+
| ### 1. Star     | ###         | ###        | ###         | ###      |
| t with Raw data |             |            |             |          |
+-----------------+-------------+------------+-------------+----------+
| ### 2. Spe      | ### \# s    | ### Raw D  | ### Inc     | ### Valu |
| ctral Averaging | pectra per  | N; .rfd^2^ | orrect \# s | es off b |
|                 | observation |            | pectra per  | y factor |
|                 |             |            | observation |          |
+-----------------+-------------+------------+-------------+----------+
| ### 3. Da       | ###  T      | ### Dark   | ### Dark    | ### Vari |
| rk Subtraction  |             |  subtracte |  spec. temp | able, gr |
|                 |             | d DN; .dks | orally dist | eater in |
|                 |             |            | ant from ta |  longer  |
|                 |             |            | rget spec.; |          |
|                 |             |            |  Motor bias |          |
+-----------------+-------------+------------+-------------+----------+
| ### 4. G        | ###  Gain   | ###        | ### 1x      | #        |
| ain correction  |             |  N/A (inte | or 10x Gain | ## Syste |
|                 |             | rnal step) |             | matic er |
|                 |             |            |             | ror in G |
|                 |             |            |             | e values |
+-----------------+-------------+------------+-------------+----------+
| ### 5. Cross    | ### Ge      | ###        | ### C       | ### Er   |
| talk correction |  Correspond |  N/A (inte | oefficients | ror in l |
|                 | ing InGaAs  | rnal step) |  for 2^nd^- | ower Ge  |
|                 |             |            | order light |          |
+-----------------+-------------+------------+-------------+----------+
| ### 6. Mirror p | ###         | ### Cal    | ###         | ###      |
| os. correction  | Mirror pos. | ibrated DN | Wrong mirro | Variable |
|                 |             |            | r pos. or c |          |
|                 |             |            | oefficients |          |
+-----------------+-------------+------------+-------------+----------+
| ### 7. Photome  | ###  Of     | ###        | ### I       | ### Po   |
| tric correction | f-Sun angle | Calibrated | mproper mod | or corre |
|  for caltarget  |             |  DN (calta | el; s/c poi | lation o |
|                 |             | rget obs.) | nting error | f caltar |
|                 |             |            |             | get obs. |
+-----------------+-------------+------------+-------------+----------+
| ### 8. Radia    | ###  Slit   | ### Radi   | ### Artifa  | ###      |
| nce calibration |             | ance; .rad | cts/ inaccu |  Propaga |
|                 |             |            | racies in c | ted arti |
|                 |             |            | oefficients | facts in |
|                 |             |            |             |  spectra |
+-----------------+-------------+------------+-------------+----------+
| ###             | ### Sol     | ###        | ### Inc     | #        |
| 9. Radiance Fac | ar distance |  Radiance  | orrect sola | ## Non-r |
| tor conversion  |             | factor (*I | r distance/ | ealistic |
|                 |             | /F*); .iof | solar model |  radianc |
|                 |             |            |             | e factor |
+-----------------+-------------+------------+-------------+----------+
| ### 10. Empir   | ### none    | ###        | #           | ### Ad   |
| ical correction |             |  Radiance  | ## Variatio | ded nose |
|                 |             | factor (*I | n in effect |          |
|                 |             | /F*); .iof |             |          |
+-----------------+-------------+------------+-------------+----------+
| ##              | ### Mirr    | ###        | ### Incorr  | ###      |
| # 11. Polarizat | or position |  Radiance  | ect polariz | variable |
| ion correction  |             | factor (*I | ation effet |          |
|                 |             | /F*); .iof |             |          |
+-----------------+-------------+------------+-------------+----------+

## 

## **1. Raw NIS Data**

## 

## Raw NIS data are represented in counts or data numbers (DN). For each channel, a DN corresponds to one least significant bit from the 12-bit analog-to-digital converter of the individual detector and represents a certain number of photons of the appropriate wavelength passing though the slit. A DN has a value of approximately 1.22 mV output from the detector pre-amplifiers from the InGaAs channels and the Ge channels when at gain 1x (0.12 mV at gain 10x). Warren et al. (1997) discuss the electronics governing detector response in greater detail. 

## 

## **2. Spectral Averaging**

The basic unit of spectral data for any given NIS channel is the
integrated DN accumulated by each detector element. For any single
observation, up to 63 one-second integrations can be summed. To get the
average raw signal per second for each channel, the total signal is
divided by the number of seconds in the observation. Available proxies
for the standard deviation of the NIS signal include noise values
derived from proximate dark observations and reference in-space
sequences of dark spectra obtained during cruise (Warren *et al.*, 1997
and Izenberg et al., 2000.)

## 

## **3. Dark Subtraction**

Dark data are spectra taken with the slit closed, or open and looking
into empty space. The signal in a dark spectrum represents the
background electronic and other noise inherent in the instrument (e.g.
the voltage applied to the NIS shutter motor) and is removed as part of
the calibration process.

Dark spectra are derived from interleaved darks and spectra, bounding
observations before and after spectra, or as a running fit of darks
between many data observations. Dark spectra are subtracted from the
averaged target spectrum. The standard deviation of the dark data is a
representation of the noise for the associated spectra in the sequence.

## **4. Gain Correction**

The Germanium detector has a selectable gain of 1x or 10x. If the gain
is set at 10x, then the Ge signal needs to be corrected to 1x in order
to use radiometric coefficients generated for 1x gain.

The observed effect on the Ge gain ratio in-flight *vs.* on-ground is
approximately a 0.9% decrease. This variation does not affect the
relative channel-to-channel response and is within the noise when
comparing Ge and InGaAs spectra. Currently, NIS calibration uses the
in-space-derived coefficient for 10x gain. TheGain correction factor is
9.84 3+/- 0.030.

## **5. Spectral Crosstalk Correction**

## 

## Spectral crosstalk in NIS results from first-order wavelength light falling onto and being detected by the shortest-wavelength Ge detector elements. The first five Ge channels have measurable crosstalk signals, which can be removed by subtracting the proper percentage of the corresponding InGaAs signal from the Ge signal. The coefficients for the crosstalk correction are given in Table A-I.

## **6. Mirror Position Correction**

The NIS scan mirror gives the instrument a 140° wide, selectable field
of view with 350 distinct mirror positions. Varying mirror position
affects the light coming into the detectors in a wavelength-dependent
manner as a result of polarization and reflection efficiency variations.
An interpolated curve-fit correction for each channel based on mirror
position is applied to NIS data as part of the calibration process.
Equations and coefficients describing relative response as a function of
mirror position are shown in Appendix B.

## **7. Caltarget Photometric Correction** 

The NIS caltarget consists of a roughened surface coated with a smooth
deposit of gold (Infragold™). The target is fixed and viewed by the
instrument at a constant emission angle, *e*, of 75° (mirror position
0), with 5° of yaw, and with an incidence angle *[i]{.underline}* = 50°.

In caltarget observations, small differences in observing geometry
caused by small variations in spacecraft pointing are compensated by a
photometric correction. The equation for the correction is:

$\text{RRS}_{\lambda\text{,yaw}}\text{ = e}^{\text{-0}\text{.}\text{15764}\sqrt{\text{30-}\text{yaw}}}$
(4)

where RRS is the reflectance relative to specular geometry for
wavelength at the given spacecraft yaw off-Sun. The photometric
correction is the ratio of the RRS (at a yaw of 5°) with the RRS at the
actual yaw angle of the caltarget (Warren *et al.* 1997).

## **8. Radiance and Reflectance Conversion**

Calibration of NIS data to absolute radiometric units enables quick and
easy comparison with other spectroscopic datasets, essential to creating
complete spectral/spatial data cubes for mineral identification and
characterization.

The data are converted to radiance (W m^-2^ sr^-1^ µm^-1^) using APL
OCF-determined tables (Appendix A). The radiance factor (*I/F*; Hapke
1981) of the area targeted by NIS is calculated as the ratio of the
target radiance observed by NIS to the radiance of a solar-illuminated
Lambertian surface of albedo = 1 observed at 0 phase angle and located
at the same distance from the Sun. For generation of NIS I/F spectra, we
used the World Meteorological Organization 1 AU top-of-atmosphere solar
flux spectrum (Wehrli, 1986) convolved to the NIS bandpasses and scaled
by the square of the heliocentric distance of the NIS observations.

## **9. High Frequency Noise Correction**

This corrects a channel to channel systematic variation that is constant
throughout the orbital mission. The smoothes the spectrum considerably
by removing an invariant noise signal.

## 

## **10. Polarization Correction**

Data at certain mirror positions (usually high positions e.g. low phase
flyby) are affected by the polarization properties of the NIS Mirror. A
polarization correction is implemented to solve this.

##### Calibration Error Sensitivity

See Izenberg et al., 2000 for a discussion of possible effects of
calibration error by source.

##### Validation of Calibration Coefficients

Validation of the absolute calibration was performed through
observations of the Earth and Moon and of Eros itself during the initial
flyby (see Izenberg et al., 2000.)

**NISCAL**

The calibration of NIS described in this paper has been implemented in a
command-line driven set of algorithms called NISCAL. The program, coded
in Interactive Data Language (IDL^®^), reads an editable configuration
file and processes ASCII lists of NIS raw FITS files. Each sequence in
the input list is calibrated to the selected level (raw,
dark-subtracted, or calibrated DN, radiance, or *I/F*). The calibration
software used to produce the PDS-archived data sets will also be
available from the MSI/NIS team. An example of this software
(unsupported) will be provided in the document area of Level 2 NIS data.

**[Appendix A. NIS Calibration Coefficients]{.underline}**

Table A-I presents basic wavelength and calibration data for the NIS
detectors. The crosstalk correction is the value by which the signal in
the crosstalk channels is multiplied before subtracting from the
respective Ge channel. The slit ratio is the factor by which the DN
values taken with the wide slit are divided to get equivalent values to
the narrow slit. The DN-Radiance coefficients are in units of DN/(W
m^-2^ sr^-1^ m^‑1^). Coefficients are derived from in-lab measurements
using a gold integrating sphere.

Noise-equivalent spectral radiance (NESR) values are derived from 2112
10-second observations of dark space and given in radiance units of W
m^-2^ sr^-1^ m^‑1^ as discussed in section 5.4.2.2. Channels that are in
cutoff and receive little or no signal are italicized.

######## Appendix B. NIS Scan Mirror Coefficients

Coefficients for the polynomial fits to the relative response of spectra
at different mirror positions for each NIS channel are shown for the
Narrow slit, along with the goodness of fit (r^2^), in Table B-I. The
equation followed is:

> Relative Response = $\sum_{i = 0}^{5}{m_{i}x^{i}}$ (B1)

where *x* is the mirror position. Relative response in the lab was
normalized to 1.0 at position 188 (the mirror position of the primary
radiometric calibration measurements). Error values are well under 1% in
most channels, the exceptions being those in cutoff. Selected channels
are plotted in Fig. B1. Wide-slit corrections are similar, though error
bars are smaller.

Table A-I. Germanium (1-32) and Indium/Gallium/Arsenide (33-64) Detector
Channels

<table>
<colgroup>
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 4%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 4%" />
<col style="width: 8%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 7%" />
</colgroup>
<tbody>
<tr class="odd">
<td><h1 id="section-14"><strong>#</strong></h1></td>
<td><p><strong>Band Center</strong></p>
<p><strong>(nm)</strong></p></td>
<td colspan="2"><strong>Crosstalk Corr. Ch</strong></td>
<td><strong>Slit ratio</strong></td>
<td><strong>DN-rad</strong></td>
<td><strong>DN-rad err.</strong></td>
<td><strong>NESR</strong></td>
<td><h1 id="section-15"><strong>#</strong></h1></td>
<td><strong>Band Center (nm)</strong></td>
<td><strong>Slit ratio</strong></td>
<td><strong>DN-rad</strong></td>
<td><strong>DN-rad err.</strong></td>
<td><strong>NESR</strong></td>
</tr>
<tr class="even">
<td>1</td>
<td>816.2</td>
<td>0.675</td>
<td>39</td>
<td>1.94</td>
<td>15.8</td>
<td>0.07</td>
<td>0.35</td>
<td><em>33</em></td>
<td><em>1371.8</em></td>
<td><em>2.67</em></td>
<td><em>0.3</em></td>
<td><em>1.00</em></td>
<td><em>13.60</em></td>
</tr>
<tr class="odd">
<td>2</td>
<td>837.8</td>
<td>0.654</td>
<td>40</td>
<td>2.04</td>
<td>19.2</td>
<td>0.08</td>
<td>0.25</td>
<td><em>34</em></td>
<td><em>1414.9</em></td>
<td><em>3.20</em></td>
<td><em>1.3</em></td>
<td><em>0.09</em></td>
<td><em>4.06</em></td>
</tr>
<tr class="even">
<td>3</td>
<td>859.4</td>
<td>0.218</td>
<td>41</td>
<td>2.11</td>
<td>24.1</td>
<td>0.09</td>
<td>0.23</td>
<td>35</td>
<td>1458.0</td>
<td>2.39</td>
<td>12.9</td>
<td>0.28</td>
<td>0.34</td>
</tr>
<tr class="odd">
<td>4</td>
<td>881.0</td>
<td>0.091</td>
<td>42</td>
<td>2.06</td>
<td>28.7</td>
<td>0.06</td>
<td>0.18</td>
<td>36</td>
<td>1501.1</td>
<td>1.98</td>
<td>54.8</td>
<td>0.11</td>
<td>0.07</td>
</tr>
<tr class="even">
<td>5</td>
<td>902.7</td>
<td>0.045</td>
<td>43</td>
<td>2.06</td>
<td>32.1</td>
<td>0.12</td>
<td>0.19</td>
<td>37</td>
<td>1544.2</td>
<td>1.87</td>
<td>112.6</td>
<td>0.29</td>
<td>0.03</td>
</tr>
<tr class="odd">
<td>6</td>
<td>924.3</td>
<td>0.008</td>
<td>44</td>
<td>2.08</td>
<td>36.5</td>
<td>0.10</td>
<td>0.16</td>
<td>38</td>
<td>1587.3</td>
<td>2.00</td>
<td>145.3</td>
<td>0.51</td>
<td>0.03</td>
</tr>
<tr class="even">
<td>7</td>
<td>945.9</td>
<td>0.003</td>
<td>45</td>
<td>2.07</td>
<td>41.6</td>
<td>0.08</td>
<td>0.14</td>
<td>39</td>
<td>1630.4</td>
<td>2.03</td>
<td>163.2</td>
<td>0.49</td>
<td>0.03</td>
</tr>
<tr class="odd">
<td>8</td>
<td>967.5</td>
<td>0.002</td>
<td>46</td>
<td>2.06</td>
<td>47.7</td>
<td>0.11</td>
<td>0.10</td>
<td>40</td>
<td>1673.6</td>
<td>2.00</td>
<td>192.9</td>
<td>0.43</td>
<td>0.02</td>
</tr>
<tr class="even">
<td>9</td>
<td>989.1</td>
<td>-</td>
<td>-</td>
<td>2.06</td>
<td>51.7</td>
<td>0.15</td>
<td>0.11</td>
<td>41</td>
<td>1716.7</td>
<td>2.06</td>
<td>222.2</td>
<td>0.52</td>
<td>0.02</td>
</tr>
<tr class="odd">
<td>10</td>
<td>1010.7</td>
<td>-</td>
<td>-</td>
<td>2.07</td>
<td>56.6</td>
<td>0.15</td>
<td>0.10</td>
<td>42</td>
<td>1759.8</td>
<td>2.05</td>
<td>248.8</td>
<td>0.68</td>
<td>0.02</td>
</tr>
<tr class="even">
<td>11</td>
<td>1032.3</td>
<td>-</td>
<td>-</td>
<td>2.07</td>
<td>59.2</td>
<td>0.15</td>
<td>0.09</td>
<td>43</td>
<td>1802.9</td>
<td>2.03</td>
<td>273.3</td>
<td>0.69</td>
<td>0.01</td>
</tr>
<tr class="odd">
<td>12</td>
<td>1053.9</td>
<td>-</td>
<td>-</td>
<td>2.07</td>
<td>65.6</td>
<td>0.20</td>
<td>0.08</td>
<td>44</td>
<td>1846.0</td>
<td>2.01</td>
<td>296.4</td>
<td>0.97</td>
<td>0.01</td>
</tr>
<tr class="even">
<td>13</td>
<td>1075.5</td>
<td>-</td>
<td>-</td>
<td>2.07</td>
<td>68.4</td>
<td>0.17</td>
<td>0.07</td>
<td>45</td>
<td>1889.1</td>
<td>2.12</td>
<td>321.1</td>
<td>1.03</td>
<td>0.01</td>
</tr>
<tr class="odd">
<td>14</td>
<td>1097.1</td>
<td>-</td>
<td>-</td>
<td>2.08</td>
<td>70.7</td>
<td>0.20</td>
<td>0.08</td>
<td>46</td>
<td>1932.2</td>
<td>2.27</td>
<td>358.1</td>
<td>0.89</td>
<td>0.01</td>
</tr>
<tr class="even">
<td>15</td>
<td>1118.8</td>
<td>-</td>
<td>-</td>
<td>2.08</td>
<td>37.2</td>
<td>0.11</td>
<td>0.13</td>
<td><em>47</em></td>
<td><em>1975.3</em></td>
<td><em>2.04</em></td>
<td><em>395.3</em></td>
<td><em>1.96</em></td>
<td><em>0.03</em></td>
</tr>
<tr class="odd">
<td>16</td>
<td>1140.4</td>
<td>-</td>
<td>-</td>
<td>2.08</td>
<td>77.9</td>
<td>0.24</td>
<td>0.07</td>
<td>48</td>
<td>2018.4</td>
<td>1.99</td>
<td>437.3</td>
<td>1.02</td>
<td>0.01</td>
</tr>
<tr class="even">
<td>17</td>
<td>1162.0</td>
<td>-</td>
<td>-</td>
<td>2.08</td>
<td>77.5</td>
<td>0.20</td>
<td>0.07</td>
<td>49</td>
<td>2061.5</td>
<td>2.09</td>
<td>439.1</td>
<td>1.12</td>
<td>0.01</td>
</tr>
<tr class="odd">
<td>18</td>
<td>1183.6</td>
<td>-</td>
<td>-</td>
<td>2.13</td>
<td>73.4</td>
<td>0.20</td>
<td>0.07</td>
<td>50</td>
<td>2104.7</td>
<td>2.11</td>
<td>438.6</td>
<td>1.34</td>
<td>0.01</td>
</tr>
<tr class="even">
<td>19</td>
<td>1205.2</td>
<td>-</td>
<td>-</td>
<td>2.11</td>
<td>69.9</td>
<td>0.18</td>
<td>0.07</td>
<td>51</td>
<td>2147.8</td>
<td>2.07</td>
<td>452.1</td>
<td>1.13</td>
<td>0.01</td>
</tr>
<tr class="odd">
<td>20</td>
<td>1226.8</td>
<td>-</td>
<td>-</td>
<td>2.18</td>
<td>68.0</td>
<td>0.17</td>
<td>0.08</td>
<td>52</td>
<td>2190.9</td>
<td>2.06</td>
<td>492.8</td>
<td>1.67</td>
<td>0.01</td>
</tr>
<tr class="even">
<td>21</td>
<td>1248.4</td>
<td>-</td>
<td>-</td>
<td>2.07</td>
<td>77.6</td>
<td>0.13</td>
<td>0.07</td>
<td>53</td>
<td>2234.0</td>
<td>2.05</td>
<td>497.8</td>
<td>1.76</td>
<td>0.01</td>
</tr>
<tr class="odd">
<td>22</td>
<td>1270.0</td>
<td>-</td>
<td>-</td>
<td>2.10</td>
<td>84.7</td>
<td>0.17</td>
<td>0.07</td>
<td>54</td>
<td>2277.1</td>
<td>2.13</td>
<td>519.7</td>
<td>1.71</td>
<td>0.01</td>
</tr>
<tr class="even">
<td>23</td>
<td>1291.6</td>
<td>-</td>
<td>-</td>
<td>2.12</td>
<td>216.4</td>
<td>0.45</td>
<td>0.03</td>
<td>55</td>
<td>2320.2</td>
<td>2.19</td>
<td>499.4</td>
<td>2.36</td>
<td>0.01</td>
</tr>
<tr class="odd">
<td>24</td>
<td>1313.2</td>
<td>-</td>
<td>-</td>
<td>2.14</td>
<td>215.5</td>
<td>0.42</td>
<td>0.03</td>
<td>56</td>
<td>2363.3</td>
<td>2.14</td>
<td>481.5</td>
<td>1.99</td>
<td>0.02</td>
</tr>
<tr class="even">
<td>25</td>
<td>1334.9</td>
<td>-</td>
<td>-</td>
<td>2.13</td>
<td>204.6</td>
<td>0.48</td>
<td>0.03</td>
<td><em>57</em></td>
<td><em>2406.4</em></td>
<td><em>2.15</em></td>
<td><em>386.3</em></td>
<td><em>6.00</em></td>
<td><em>0.11</em></td>
</tr>
<tr class="odd">
<td>26</td>
<td>1356.5</td>
<td>-</td>
<td>-</td>
<td>2.22</td>
<td>189.6</td>
<td>0.44</td>
<td>0.03</td>
<td>58</td>
<td>2449.5</td>
<td>2.17</td>
<td>422.2</td>
<td>4.00</td>
<td>0.08</td>
</tr>
<tr class="even">
<td>27</td>
<td>1378.1</td>
<td>-</td>
<td>-</td>
<td>2.17</td>
<td>186.7</td>
<td>0.37</td>
<td>0.03</td>
<td>59</td>
<td>2492.6</td>
<td>2.2</td>
<td>355.8</td>
<td>6.00</td>
<td>0.04</td>
</tr>
<tr class="odd">
<td>28</td>
<td>1399.7</td>
<td>-</td>
<td>-</td>
<td>2.18</td>
<td>195.4</td>
<td>0.30</td>
<td>0.03</td>
<td>60</td>
<td>2535.8</td>
<td>2.19</td>
<td>281.3</td>
<td>2.11</td>
<td>0.04</td>
</tr>
<tr class="even">
<td>29</td>
<td>1421.3</td>
<td>-</td>
<td>-</td>
<td>2.20</td>
<td>204.3</td>
<td>0.29</td>
<td>0.03</td>
<td>61</td>
<td>2578.9</td>
<td>2.43</td>
<td>138.9</td>
<td>4.07</td>
<td>0.10</td>
</tr>
<tr class="odd">
<td>30</td>
<td>1442.9</td>
<td>-</td>
<td>-</td>
<td>2.19</td>
<td>200.3</td>
<td>0.35</td>
<td>0.03</td>
<td><em>62</em></td>
<td><em>2622.0</em></td>
<td><em>2.59</em></td>
<td><em>48.5</em></td>
<td><em>2.07</em></td>
<td><em>0.31</em></td>
</tr>
<tr class="even">
<td>31</td>
<td>1464.5</td>
<td>-</td>
<td>-</td>
<td>2.21</td>
<td>168.5</td>
<td>0.34</td>
<td>0.03</td>
<td><em>63</em></td>
<td><em>2665.1</em></td>
<td><em>3.00</em></td>
<td><em>31.7</em></td>
<td><em>3.00</em></td>
<td><em>0.54</em></td>
</tr>
<tr class="odd">
<td><em>32</em></td>
<td><em>1486.1</em></td>
<td><em>-</em></td>
<td><em>-</em></td>
<td><em>2.27</em></td>
<td><em>126.4</em></td>
<td><em>0.29</em></td>
<td><em>0.05</em></td>
<td><em>64</em></td>
<td><em>2708.2</em></td>
<td><em>2.57</em></td>
<td><em>40.2</em></td>
<td><em>0.38</em></td>
<td><em>0.30</em></td>
</tr>
</tbody>
</table>

Table B-I. Mirror Equation Coefficients for the Narrow Slit

  -------- ---------- ---------- ----------- ----------- ----------- ----------- ---------- -------- ---------- ----------- ----------- ----------- ----------- ----------- ----------
  **Ch**   **m~0~**   **m~1~**   **m~2~**    **m~3~**    **m~4~**    **m~5~**    **R^2^**   **Ch**   **m~0~**   **m~1~**    **m~2~**    **m~3~**    **m~4~**    **m~5~**    **R^2^**

  1        0.92321    0.000565   -5.35E-07   -1.54E-09   \-          \-          0.982      33       7.6643     -0.13172    0.0004      \-          \-          \-          0.142

  2        0.92386    0.000736   -2.11E-06   1.79E-09    \-          \-          0.974      34       1.2016     0.001208    -5.72E-06   \-          \-          \-          0.238

  3        0.9366     0.000591   -1.51E-06   9.70E-10    \-          \-          0.986      35       0.9494     0.003073    -5.12E-05   3.34E-07    -9.56E-10   9.95E-13    0.405

  4        0.94422    0.000103   8.37E-06    -7.43E-08   2.37E-10    -2.62E-13   0.991      36       0.98749    0.000724    -1.32E-05   9.10E-08    -2.56E-10   2.41E-13    0.803

  5        0.93631    0.000664   -2.10E-06   2.07E-09    \-          \-          0.992      37       0.94082    0.001196    -9.57E-06   3.42E-08    -4.43E-11   \-          0.969

  6        0.94158    0.000345   3.88E-06    -4.26E-08   1.41E-10    -1.57E-13   0.992      38       0.92704    0.001448    -1.52E-05   8.70E-08    -2.38E-10   2.43E-13    0.990

  7        0.93443    0.00071    -2.55E-06   3.06E-09    \-          \-          0.981      39       0.93902    0.00074     -2.94E-06   3.82E-09    \-          \-          0.990

  8        0.93493    0.00072    -2.54E-06   2.92E-09    \-          \-          0.998      40       0.9404     0.000726    -2.93E-06   3.91E-09    \-          \-          0.990

  9        0.93558    0.000702   -2.33E-06   2.49E-09    \-          \-          0.988      41       0.93967    0.000856    -4.92E-06   1.34E-08    -1.40E-11   \-          0.992

  10       0.93641    0.00067    -2.08E-06   1.97E-09    \-          \-          0.988      42       0.93807    0.000845    -4.73E-06   1.26E-08    -1.33E-11   \-          0.993

  11       0.93222    0.000774   -2.88E-06   3.55E-09    \-          \-          0.999      43       0.93685    0.000833    -4.20E-06   9.58E-09    -8.21E-12   \-          0.991

  12       0.93144    0.000761   -2.77E-06   3.34E-09    \-          \-          0.997      44       0.92948    0.001302    -1.24E-05   6.76E-08    -1.88E-10   2.01E-13    0.991

  13       0.93151    0.000756   -2.69E-06   3.17E-09    \-          \-          0.998      45       0.93572    0.000732    -2.54E-06   -2.48E-10   9.95E-12    \-          0.949

  14       0.93127    0.000802   -3.01E-06   3.76E-09    \-          \-          0.999      46       0.92028    0.00196     -2.30E-05   1.38E-07    -3.86E-10   4.05E-13    0.988

  15       0.9273     0.000865   -3.33E-06   4.23E-09    \-          \-          0.996      47       0.91705    0.001431    -1.31E-05   6.92E-08    -1.68E-10   1.36E-13    0.970

  16       0.92504    0.000853   -3.17E-06   3.93E-09    \-          \-          0.996      48       0.93987    0.000612    -2.04E-06   2.31E-09    \-          \-          0.995

  17       0.9094     0.001261   -6.93E-06   1.79E-08    -1.78E-11   \-          0.997      49       0.9243     0.001433    -1.43E-05   7.89E-08    -2.16E-10   2.27E-13    0.982

  18       0.89415    0.001618   -9.98E-06   2.86E-08    -3.05E-11   \-          0.996      50       0.93946    0.000789    -3.40E-06   2.43E-09    1.76E-11    -3.07E-14   0.992

  19       0.89229    0.00192    -1.55E-05   6.87E-08    -1.61E-10   1.54E-13    0.988      51       0.92551    0.001923    -2.29E-05   1.34E-07    -3.64E-10   3.64E-13    0.964

  20       0.90546    0.002412   -2.81E-05   1.65E-07    -4.59E-10   4.77E-13    0.991      52       0.93157    0.001736    -2.31E-05   1.54E-07    -4.70E-10   5.26E-13    0.968

  21       0.9042     0.002365   -2.61E-05   1.45E-07    -3.86E-10   3.87E-13    0.995      53       0.92516    0.000956    -4.31E-06   7.01E-09    -1.90E-12   \-          0.983

  22       0.89116    0.002572   -2.77E-05   1.52E-07    -4.02E-10   4.02E-13    0.993      54       0.91338    0.002182    -2.44E-05   1.37E-07    -3.65E-10   3.68E-13    0.964

  23       0.88659    0.002631   -2.80E-05   1.53E-07    -4.05E-10   4.09E-13    0.995      55       0.9388     0.00058     1.17E-06    -4.23E-08   1.91E-10    -2.54E-13   0.686

  24       0.88366    0.002716   -2.88E-05   1.56E-07    -4.10E-10   4.10E-13    0.994      56       0.87962    0.003977    -5.87E-05   4.07E-07    -1.27E-09   1.42E-12    0.757

  25       0.87886    0.002887   -3.11E-05   1.70E-07    -4.51E-10   4.58E-13    0.992      57       0.85153    -5.70E-05   6.33E-05    -6.89E-07   2.54E-09    -3.08E-12   0.483

  26       0.86747    0.003478   -3.99E-05   2.26E-07    -6.10E-10   6.24E-13    0.989      58       0.78555    0.009053    -0.00014    9.56E-07    -2.83E-09   3.03E-12    0.724

  27       0.85509    0.004041   -4.77E-05   2.73E-07    -7.36E-10   7.49E-13    0.987      59       0.85173    0.002986    -1.93E-05   5.40E-09    2.34E-10    -4.29E-13   0.689

  28       0.84261    0.004447   -5.21E-05   2.94E-07    -7.84E-10   7.92E-13    0.982      60       0.8848     0.002725    -2.80E-05   1.63E-07    -4.71E-10   5.08E-13    0.652

  29       0.83447    0.004708   -5.57E-05   3.16E-07    -8.45E-10   8.53E-13    0.983      61       1.0154     -0.00789    0.000162    -1.21E-06   3.79E-09    -4.21E-12   0.271

  30       0.81989    0.005046   -6.03E-05   3.47E-07    -9.43E-10   9.64E-13    0.983      62       0.31387    0.03131     -0.0005     3.39E-06    -1.03E-08   1.13E-11    0.593

  31       0.79523    0.005453   -6.37E-05   3.65E-07    -9.87E-10   1.01E-12    0.984      63       2.682      0.008776    -0.00029    9.16E-07    \-          \-          0.629

  32       0.75231    0.006354   -7.40E-05   4.28E-07    -1.17E-09   1.20E-12    0.992      64       0.19726    -0.00642    9.18E-05    -2.21E-07   \-          \-          0.372
  -------- ---------- ---------- ----------- ----------- ----------- ----------- ---------- -------- ---------- ----------- ----------- ----------- ----------- ----------- ----------

High Frequency noise correction factors (1/channel for 64 channels)

0.97195099

1.0080530

1.0011220

1.0373142

1.0165215

0.99610201

0.98198248

0.98214284

1.0068402

1.0137654

0.98472317

1.0053838

1.0104629

1.0065989

1.0023619

0.99349747

0.99075956

0.99311879

0.98999957

0.98399399

1.0047502

0.98706266

1.0215776

1.0136570

1.0161188

0.97822087

1.0159139

0.99563183

1.0082314

0.99687000

0.99146403

1.0245403

1.00000

1.00000

1.00000

1.0013578

0.98990027

0.99141693

0.99755823

1.0093125

1.0013340

1.0101287

0.98040833

1.0037661

1.0072696

1.0190822

1.0143599

1.0066883

0.96399363

0.95082114

0.95760306

0.98213811

1.0190246

1.0601838

0.98500674

1.0860694

0.97710449

0.96796369

0.92283385

1.0708286

1.00000

1.00000

1.00000

1.00000

**References**

[Hapke, B. W.]{.smallcaps} 1981. Bidirectional reflectance
spectroscopy, 1. Theory. *J. Geophys. Res*. **86**, 3039-3054.

Izenberg N.R. et al., In flight calibration of the Near Earth Asteroid
Rendezvous Mission's Near Infrared Spectrometer, Icarus 148, 550-571,
2000.

[Warren, J., K. Peacock, E. H. Darlington, S. L. Murchie, S. Oden, J.
Hayes, J. F. Bell III, S. Krein, and A. Mastandrea]{.smallcaps} 1997.
Near-infrared spectrometer for the Near Earth Asteroid Rendezvous
mission. *Space Sci. Rev*. **82**, 101-167.

W[ehrli]{.smallcaps}, C. (Ed.) 1986. World Climate Research Programme
Publication Series, No. 7, WMO ITD-No. 149, 119-126, October.